Contents

Welcome message

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Practical information
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Public transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to get to the conference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Internet access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Slack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Social media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Broadcasting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gastronomy meets astronomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Information for speakers and poster presenters
Speakers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The day before your talk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The day of your talk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Poster presenters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
First ﬂash session - Monday, 25th September - 5 pm/5:30 pm . . . . . . . . . . . . . . . .
Second ﬂash session - Tuesday, 26th September - 4:30 pm/5 pm . . . . . . . . . . . . . .

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Social activities
Astronomy on Tap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Excursion to Varberg Fortress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Social dinner at Wijkanders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Excursion to the Onsala Space Observatory . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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About
Scientiﬁc Organising Committee (SOC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Local Organising Committee (LOC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Timetable
Monday, 25th September, 2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tuesday, 26th September, 2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wednesday, 27th September, 2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thursday, 28th September, 2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Friday, 29th September, 2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Posters

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Talks abstracts
Monday, 25th September, 2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tuesday, 26th September, 2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wednesday, 27th September, 2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thursday, 28th September, 2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Friday, 29th September, 2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Posters abstracts

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Code of conduct

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Covid-19 recommendations

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Welcome message
Dear Participants,
It is our great pleasure to welcome you to the Cosmic Dust conference, held from the 25th to the 29th of
September in the beautiful city of Gothenburg, Sweden. This conference aims to serve as a multidisciplinary
platform for researchers from around the world to exchange ideas, discover novel opportunities, andbroaden their understanding of the fascinating subject of interstellar dust.
The conference is unique in its endeavor to bring together experts from theoretical, observational, andexperimental backgrounds to create a dialogue about dust in various cosmic settings. We believe that eachof these approaches oﬀers invaluable insights.
As we delve into the intricacies of dust grains that permeate our universe, inﬂuence star formation, and contribute to complex chemical networks, it becomes clear that understanding these seemingly inconspicuous
particles has implications far beyond what meets the eye—or even the telescope.
We have carefully curated a program that we believe caters to the diversity of topics and methodologies inthe ﬁeld of interstellar dust studies. We are delighted to have you in Gothenburg, a city that epitomises theblend of tradition and modernity, much like the interdisciplinary nature of our conference. While you’rehere, we encourage you to explore the city’s rich history, dynamic culture, and natural beauty, and hopethat your experience extends beyond the academic setting.
We want to extend special thanks to the Knut and Alice Wallenberg foundation as well as the Astrophysics
and Plasma physics department (AoP) for the ﬁnancial support. We also would like to thank all the volunteers
who have worked behind the scenes to make this conference a reality. A special thank to Carlos Buchmann,
the technician of the Venue, for taking care of the sounds and images during the conference as well as fordesigning the oﬃciel poster of the conference. Your time, eﬀort, and contributions have been invaluable.
We invite you to actively participate, collaborate, and contribute, making the most of the opportunities
for learning and networking that these next few days will oﬀer. Together, let us pave the way for new
understandings, methodologies, and even the paradigms through which we understand interstellar dust.
Wishing you an inspiring and productive time at the conference.
Best regards,
The LOC of the Cosmic Dust conference4Practical information

General information
Currency, ATMs, and credit cards
The currency of Sweden is the swedish krona (SEK). SEK 1 corresponds to roughly EUR 0.084 or USD 0.09.
In general, there is no need to withdraw any cash as virtually all places accept debit and credit cards. Should
you anyway need to withdraw cash, there are ATMs at the airport and train station, and few can be found in
the city as well.
We, however, strongly recommend using your credit/debit card only as we cannot guarantee that you will
be able to use all the cash you bring with you.
Göteborg City Card
Göteborg City Card gives you free admission to lots of entertainment, sights, excursion, Liseberg amusementpark (opposite the conference venue) and many museums. Parking and travel with trams, buses and boats
are included. You will also get shopping booklets with discounts in selected stores. Maximise your stay in
Gothenburg. The card is valid for 24, 48 or 72 h. More information: www.goteborg.com/citycard
Bike rental: Styr & Ställ
Gothenburg is a bike friendly city. Throughout the city you will ﬁnd bike stands with rental bikes. For only SEK
75 you can rent a bicycle as often as you wish. The ﬁrst half hour of each journey is always free, regardlessof the number of journeys per day. Short time visitors can choose the 3-Day Pass, which can be purchasedfrom any of the credit card terminals for just SEK 25. It is also included in the Göteborg City Card. Moreinformation: goteborg.com/en/styr-stall
Emergency contacts
Emergency number: 112
Healthcare advices: +46 771 1177 00
Police: +46 77 33 113 13
Thiebaut Schirmer (chair): +46 73 890 44 82
LOC mail address: cosmic-dust-sweden@sciencesconf.org

Public transport• is run by Västtraﬁk. Tickets cannot often be purchased on board on buses (mostly trams, by a bankcard) and from the app you can also email the receipts.
• The recommended way of purchasing tickets is, therefore, through the mobile app (Västtraﬁk ToGo).
5You can also buy tickets at vending machines inside trams, or at some kiosks (Pressbyrån). Note thatcash payment is not possible, and a bank card (preferably a credit card) is required.
• Tickets are valid for 90 minutes in trams, buses, trains, ferries (zone of Gothenburg).
• If you need to book a taxi, it costs approximately SEK 500 to/from Landvetter Airport. Ask for a ﬁxed
price. The driver should have a taxi ID card clearly displayed in the vehicle. Service is included in
the taximeter price; therefore, tipping is not expected. Avoid unlicensed taxis. We recommend Taxi
Göteborg: +46 (0)31 650 00 or their website.
• Airport buses – Flygbussarna. It takes 30 minutes to travel between the “Landvetter” airport and thecity center, the bus stop by central station is called “Nils Ericson Terminalen (Göteborg C)”. Tickets
costs SEK 119 single way and SEK 238 return, no cash is accepted on the bus only credit cards. For
information and timetable, please visit www.ﬂygbussarna.se
We recommend you to install the mobile app and connect your credit/debit card to it before your arrival
to Gothenburg such as you just have to buy a ticket whenever you want.

How to get to the conference
The conference will take place in the room called RunAn (450 places, marked by the red pin on the image
below) located in the Chalmers conference center, at the ﬁrst ﬂoor.
Visiting address: Chalmers Konferens & Restauranger, Main entrance, Chalmers platsen 1, 412 58 Göteborg,
Sweden.
Train station

Tram/BusstationEntrance 1

VENUE

Entrance 2

Getting here by tram or by bus: The following buses are operating Chalmers: 16, 18, 19, 55, 58, 158 and 753.
In addition, the trams 6, 7, 8 10 and 13 are operating Chalmers. Please visit Västtraﬁk for details.
By car: Please consult a map and/or GPS for the best alternatives for reaching your destination on campus
by car.
Arriving in Gothenburg by train: Exit the train at the central station/the Nils Ericson terminal. Take bus 16,
destination Högsbohöjd, from the stop Nordstan, just outside the terminal. From Drottningstorget, also just6

outside the central station, you can take tram 13, heading “Sahlgrenska”, to Chalmers. From Brunnsparken,
approximately 500 meters from the central station, there are additional tram lines that will take you to
Chalmers. Please visit Västtraﬁk for details.
If you travel via train from the south: your train will have ﬁnal stop at Mölndal station, and it will not reachthe central station. Buses to reach the Chalmers Johanneberg Campus will be available (20 to 25-minuteride), and also to reach the central station. Please visit Västtraﬁk for details or download the Västtraﬁk ToGo
app to plan your journey.

Internet access
Eduroam is available on the entire campus including the conference venue at Kårhus (union building). In
case you do not have an eduroam account, there is the possibility to connect as a guest to NOMAD, and wewill have a list of usernames and passwords to connect locally. If you need one username and a password,
we will provide you with one when you register.

SlackThis conference uses Slack as its main method of communication during the conference and to facilitate
real-life socialising. Each day has a separate “Channel”, where we provide space to discuss the topics raised
during the talks. Similarly, we prepared a poster channel as a convenient place to contact and address yourquestions to the poster presenters. Questions during the talks will be copied to Slack, and we encourage
participants to continue their discussions with the audience as “Replies” to their talk. Please join us on
Slack, and please say hi and introduce yourselves in our “Introductions” channel: link to the Slack
We remind our participants of our code of conduct, and note that unwelcome messages can be reported toany of the members of the LOC.

Figure 1: QR code towards the slack.

Social media
For those who are active on social media (X, Instagram, Facebook, etc.), feel free to use this hashtag if you
post pictures associated to the conference: #CosmicDustSweden2023. We will gather the pictures after
the conferences for the website.
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Broadcasting
For those who were not able to come, here is the information to access the conference (for free) online.
Please do not hesitate to share this link:
Join from a PC, Mac, iPad, iPhone or Android device:
Please click this URL to join. https://chalmers.zoom.us/j/68451951659
Passcode: 926471
Description: Within our collaboration on Cosmic Dust, funded by the Knut and Alice Wallenberg foundation,
we are organizing a conference in Gothenburg (25th-29th September 2023) on dust, near and far.
Or One tap mobile:+46850163827„68451951659#„„*926471# Sweden+46850500828„68451951659#„„*926471# Sweden
Or join by phone:
Dial(for higher quality, dial a number based on your current location):
Sweden: +46 8 5016 3827 or +46 8 5050 0828 or +46 8 5050 0829 or +46 8 5052 0017 or +46 850 539 728
or +46 8 4468 2488
Webinar ID: 684 5195 1659
Passcode: 926471
International numbers available: https://chalmers.zoom.us/u/cctbCB7mIt
Or an H.323/SIP room system:
H.323: 109.105.112.236 or 109.105.112.235
Webinar ID: 684 5195 1659
Passcode: 926471
SIP: 68451951659@109.105.112.236 or 68451951659@109.105.112.235
Passcode: 926471

Gastronomy meets astronomy
The conference includes:• Morning breaks (coﬀee, tea, fruits, rolls with fresh bread, vegetables and cheese1 ).
• Afternoon breaks (coﬀee, tea, fruits, pastries of the day).
• Monday and Tuesday evenings’ mingles during the poster sessions with fresh juices and tapas:
18alternatives will be proposed for those who registered special allergies and/or diets

– Sourdough bread and goat cheese crème.
– Havgus cheese and rose hip marmelade.
– Marinated olives and artichoke.
– Thyme-glazed turnips and lemon crème.
– Smoked pork shoulder.
– Potato chips, smetana, dill and seaweed caviar.
• Wraps2 on Wednesday at 12:45 pm and Friday at 1:00 pm. Note that for technical reasons, we in theend have two options instead of four. Those who chose the meat or ﬁsh wraps will have a chicken
wrap instead (unless they speciﬁed they are vegetarian or that they have special allergies, in whichcase they will have a vegan wrap instead). Those who chose a vegetarian wrap will have a vegan wrap
instead (as for the chicken wraps, we have informed the company in charge of the wraps about theallergies). A list with the choice you made can be consulted on the registration desk and each memberof the LOC has the list so do not hesitate to ask us if you forgot what you had chosen.
– Vegan - Pulled soy, hummus, carrots, kimchi, quinoa & romaine.
– Chicken – Chili marinated chicken, soy-mayonnaise, cabbage, red onion & coriander.
Monday’s, Tuesday’s, and Thursday’s lunches are not included. Some options for lunch in the vicinity of theconference venue:Kårrestaurangen
Wijkanders
BOMBAY EXPRESS
Bov
Café Linsen
Waste
Kizuna Asian Eatery
Do not hesitate to use the Slack to discuss with other participants about possible places to eat.

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only for those who answer the poll sent two weeks before the conference.

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Information for speakers and poster presenters

Speakers
The day before your talk
Invited talks are 30 minutes long (25+5 minutes for questions), and contributed talks are 15 minutes long
(12+3 minutes for question).
We will use a Windows computer that will be connected to the video projector; thus, we need to copy
your talks on this computer before the sessions. To do so, here is the procedure: we would like you tosend us your presentation (.pdf format is recommended but it is also possible with a powerpoint format, at
this address thisch@chalmers.se) the day before your presentation, by 9 pm. The name of your ﬁle must
be ﬁrstname_lastname_daywhenyoutalk.pdf (thiebaut_schirmer_monday.pdf in my case if my talk werescheduled on Monday).

The day of your talkDuring your talk, you will be equipped with a tie microphone and a wireless device. A technician will equip
you with these devices before your session. Therefore:• if your talk is scheduled during the ﬁrst session of the day, please come in front of the stage 15
minutes before the session starts. Someone from the LOC and the technician will then take care of
you and equip you with these devices.
• if your talk is scheduled after a coﬀee break, please come in front of the stage just after the end of
the previous session (and therefore before going to the coﬀee break. In practice, if the coﬀee breakis scheduled between 10 am and 10:45 am, please come in front of the stage at 10 am if your talk isscheduled during the session that starts at 10:45 am).
• if your talk is scheduled just after lunch, please come in front of the stage 10 minutes before thesession starts. Someone from the LOC and the technician will then take care of you and equip youwith these devices.

Poster presenters
General information
The poster format is A0 with vertical orientation (portrait). Posters will be available for viewing during thewhole duration of the conference at the coﬀee-break area. You are free to hang your poster on the board
10with the corresponding number as soon as you register. Posters should be taken down by Friday lunch timeat the latest.
We have two sessions dedicated to poster viewing and discussion on Monday and Tuesday evening. During
these sessions, snacks will also be provided. On Monday and Tuesday there will be poster ﬂash presentations
which will take place in the conference room (RunAn).
Additionally, we will have a prize for the best poster(s) and a poster quiz which will be compiled based onquestions submitted by the poster presenters. Everyone is welcome and encouraged to vote on the bestposters and take part in the quiz!

First ﬂash session - Monday, 25th September - 5 pm/5:30 pm
After a few-minute introduction of this ﬂash session by members of the LOC, we will invite all the 12 membersof this ﬁrst ﬂash session to wait in line close to the stage, following the order that is indicated below. Then,
you will have one minute to advertise your poster with the help of the slide you sent us (for those who
did not send the slide on time but who want to participate, we will create a simple slide with your name,institution and poster title).
After this ﬂash presentation, we invite the following 12 speakers of this ﬁrst ﬂash session to stay close to
their respective posters as we will encourage people to come and discuss with you.
Presenter

Title

Arya M Nair

Collision induced dissociation of water pyrene molecularclusters

Miora Andriantsaralaza

DEATHSTAR – Accurate mass-loss-rate estimates for AGB
stars

Stefan van der Giessen

Disentangling galaxy and dust evolution mechanisms
through chemical abundances

Joseph Nuth

Dust coagulation in oxygen-rich circumstellar outﬂows

Minju Lee

Dust content in a z∼2 quiescent galaxy

Christina Konstantopoulou

Dust depletion of metals from from the Milky Way to z∼6

Monica Relano

Dust grain size evolution in local galaxies as a key to understand galaxy evolution

Petia Yanchulova Merica-Jones

Dust properties and extinction curves in the magellanic
clouds, M31, and M33

Pablo Rivière

Dust surface chemistry in the AB Aur protoplanetary disk:
observations and models

Elvire De Beck

Dusty feedback from massive stars

Andreas Møller Slavensky

Generating candidates in global optimization algorithms using complementary energy landscapes

11Thomas Vannieuwenhuyse

Paradigmatic examples for testing models of optical lightpolarization by spheroidal dust

Second ﬂash session - Tuesday, 26th September - 4:30 pm/5 pm
After a few-minute introduction of this ﬂash session by members of the LOC, we will invite all the 14 membersof this ﬁrst ﬂash session to wait in line close to the stage, following the order that is indicated below. Then,
you will have one minute to advertise your poster with the help of the slide you sent us (for those who
did not send the slide on time but who want to participate, we will create a simple slide with your name,institution and poster title).
After this ﬂash presentation, we invite the following 16 speakers of this ﬁrst ﬂash session to stay close to
their respective posters as we will encourage people to come and discuss with you.

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Presenter

Title

Jun YangHigh resolution spectra of the Galactic Binary Pulsar 4U
1907+09

Ilse De Looze

High-resolution view of the inner circumgalactic medium of
NGC891

Karl Gordon

Interstellar dust extinction from the far-ultraviolet to the
mid-infrared

Burcu Günay (Karl Gordon)

Mapping the interstellar dust and ice with JWSTJihye Hwang

Magnetic ﬁeld revealed by polarized dust emission in G28.34

Marco Palla

Modelling the dust cycle in local discs: unveiling the contribution of dust processes at kpc scales.

Tom Bakx

A Novel sub-mm Galaxy Emission Line Survey (ANGELS)

Ramón J. Peláez

Plasma generation and characterization of ‘dense’ and‘ﬂuﬀy’ hydrocarbon cosmic dust analogs

Gent Frederick

Project SUPERPIG

Joachim Wiegert

Radiative transfer through 3D models of dust clouds around
AGB-stars

Szanna Zsíros

Serendipitous detection of the dusty Type IIL SN 1980K with
JWST/MIRI

Giovanni Tedeschi Prades

Simulating dust dynamics in SPH and MFM hydrodynamical
simulations

Nina Sanches Sartorio

Supernova shocks and dust destruction: what role does theenvironment play?

Emelie Siderud

The eﬀect of dust opacities on winds of carbon-rich AGB
stars

Maharana SiddharthDevelopment of the Integral-ﬁeld Spectro-Polarimetry Modefor the 1.9m SAAO Spectrograph for study of ISM of nearby
galaxies

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Social activities

Astronomy on Tap

Astronomy on Tap @ Pitcher’s
Tuesday | September 26
Doors opens at 19:00 | First talk at 19:30

Clare Wethers
Quasars: Illuminating the Secrets of our Universe Since 1963
Roberta Tripodi
The first galaxies through the cosmic laboratories
After the talks we will have an astronomy related quiz. The event is free and the talks
and quiz will be held in English.
Bring your friends and come enjoy Astronomy in the pub with us!
@ Pitcher’s Majorna at Karl Johansgatan 92, 414 55 Göteborg

Astronomy on Tap is a public outreach initiative designed to bring astronomy and space science to thegeneral audience in relaxed settings like bars and breweries. These events feature short, informal talks
by experts in the ﬁeld, along with interactive activities like trivia games and quizzes. Aimed at making
science accessible and engaging, Astronomy on Tap oﬀers attendees the opportunity to learn about thelatest research and discoveries while enjoying a social, casual atmosphere.
On Tuesday evening, we are excited to present two speakers to you:
• Clare Wethers, Post-doctoral researcher at Chalmers. Quasar: Illuminating the secrets of our Universe
since 1963.
• Roberta Tripodi, PhD Student at University of Trieste. The ﬁrst galaxies through the cosmic laboratories.
This event is free and will take place in Pitcher’s Marjorna at Karl Johansgatan 92, 414 55 Göteborg. Somepeople from the LOC will probably directly go there from the Venue, after the Tuesday evening mingle. We
will make an announcement to go there as a group for those who want.

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Excursion to Varberg Fortress

BUS MEETING POINT
TO ONSALA AND VARBERG

VENUE

Buses will depart from Chalmers, nearby the library (see image above for the exact location and/or byclicking here), at 1.30 pm and take us to the small town of Varberg where we will visit the historic fortress
Varberg fortress. After a 15-minute introduction of the fortress and museum, you can keep exploring thefortress many museum-exhibitions. You can learn about fascinating ﬁnds, such as the bog body called “theBocksten man”, found in a bog in 1936 dating back to medieval times, and learn about the history of theregion, from ice sheets to beaches, and about the people who lived there. During our visit, you will be
provided with ﬁka, including coﬀee/tea and pastries (as the coﬀee place is small, we will make three groups
which will enjoy the coﬀee break during three diﬀerent time slots). You can also stroll around looking various
landmarks. The bus will then leave at 5:30 pm for an arrival at Chalmers around 6:30 pm.
Schedule:• 1:30 pm Departure from Chalmers near the library.
• 2:30 pm Arrival in Varberg.
• 2:30 pm–5:30 pm Visit.
• 5:30 pm Departure from Varberg.
• 6:30 pm Arrival at Chalmers.

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Social dinner at Wijkanders

WIJKANDERS(DINNER)

VENUE

We will have the conference dinner in Wijkanders, located on the Campus, a 5-minunte walk from the Venue.
A list with the choice you made will be available at the dinner, and each member of the LOC has the list
so do not hesitate to ask us if you forgot what you chose. During the dinner and when you will be served,
please make sure you take the right meal.
Before the dinner, some canapés and bubbles (with or without alcohol) will be oﬀered by the host institution.
Only water is included in the dinner but you will have the opportunity to buy other beverages (wine, beer,
juices, soda) during the dinner.
For those who already speciﬁed special diets (vegan, gluten free, lactose free, etc.), alternatives will be
proposed.

Starters
Salmon / Trout roe / Sesame (Salmon sashimi, ponzu, ginger emulsion, roasted cashew nuts, sesame seeds,
black cabbage, kale chips & trout roe)OR
Beetroot / Avocado / Goat cheese (vegetarian) (Beetroot steak, avocado, goat cheese cream, mache salad,salt roasted walnuts, beetroot chips & fried capers)

Main course
Cod / Trout roe / Chervil (Cod loin, champagne sauce, amandine potatoes, trout roe, chervil, chives & chiveoil)OR
Arancini / Burrata / Zucchini (vegetarian) (Arancini, smoked paprika, baked cauliﬂower, grilled zucchini,burrata, cress & basil emulsion)

DessertApple / Ice cream / Buckwheat (Apple pie with tosca topping, vanilla ice cream & fried buckwheat)16

Excursion to the Onsala Space Observatory

BUS MEETING POINT
TO ONSALA AND VARBERG

VENUE

We organise an excursion to the Onsala Space Observatory on Friday afternoon, which is free for allparticipants. This includes ﬁka and bus transfer to the observatory. Buses will depart from Chalmers, nearby
the library (see the image above for the exact location and/or by clicking there), at 1 pm.
Schedule:• 1 pm Departure from Chalmers near the library.
• 1.50 pm Arrival. Bus parks in the parking area and stays there.
• 2 pm Brief presentation in the seminar room.
• 2.20 pm Visit to 20-m telescope• 2.35 pm Walk to the visitor center.
• 2.50 pm Visit to the visitor center. Fika served.
• 3.30 pm Walk to the OTT, the FTIR spectrometer and the super tide gauge. Rerurn to the visitor center.
• 4.20 pm End of visit. Bus departs from visitor center.
• 5.20 pm Arrival at Chalmers.

17AboutScientiﬁc Organising Committee (SOC)
Susanne Aalto - Chalmers University of Technology, Sweden
Ambra Nanni - Narodowe centrum badań jądrowych (NCBJ), Poland
Denis Burgarella - Laboratoire d’Astrophysique de Marseille (LAM), France
Benoit Commerçon - Ecole Normale Supérieure de Lyon (ENS Lyon), France
Herma Cuppen - Radboud University Nijmegen, Netherlands
Frederic Galliano - Commissariat à l’Energie Atomique (CEA Saclay), France
Karl Gordon - Space Telescope Science Institute (STScI), USA
Thiem Hoang - Korea Astronomy and Space Science Institute, Korea
Liv Hornekær - Aarhus University, Denmark
Kirsten Knudsen - Chalmers University of Technology, Sweden
Gunnar Nyman - University of Gothenburg, Sweden
Dimitra Rigopoulou - University of Oxford, UK
Thiebaut Schirmer (Co-chair) - Chalmers University of Technology, Sweden
Wouter Vlemmings (Chair) - Chalmers University of Technology, Sweden
Nathalie Ysard - Institut d’Astrophysique Spatiale (IAS Orsay), France

Local Organising Committee (LOC)
Thiebaut Schirmer (Chair) - Chalmers University of Technology
Wouter Vlemmings (Co-chair) - Chalmers University of Technology
Gunnar Nyman - University of Gothenburg
Susanne Aalto - Chalmers University of Technology
Kirsten Knudsen - Chalmers University of Technology
S. Rasoul Hashemi - University of Gothenburg
Duncan Bossion - University of Gothenburg
David Gobrecht - University of Gothenburg
Martina Šimsová - University of Gothenburg
Tom Bakx - Chalmers University of Technology
Gustav Olander - Chalmers University of Technology
Theo Khouri - Chalmers University of Technology
Matthias Maercker - Chalmers University of Technology

18

Timetable
CT: Contributed Talk, IT: Invited Talk.

Monday, 25th September, 2023
8am–10am
10am–10:30am
10:30am–11am
11am–11:30am

IT

11:30am–
11:45amCT

11:45am–12pm

CT

12pm–1:30pm
1:30pm–2pmIT

2pm–2:15pm

CT

2:15pm–2:30pmCT

2:30pm–2:45pmCT

2:45pm–
3:30pmCoﬀee break

3:30pm–4pm

IT

4pm–4:30pm

IT

4:30pm–4:45pmCT

4:45pm–5pm

CT

5:00pm–
5:30pm
5:30pm–
8:00pmRegistrationCoﬀee break
WelcomeChair: Karl Gordon
Els Peeters
SETI Institute/Western
PDRs4All: JWST’s view of the Orion Bar
University
Dust grain properties in the gas-richMonique Aller
absorption systems of diverse galaxies at
Georgia Southern University
z<2Raphaël Meshaka
The dust population in PDRs: impact on
Observatoire de
PDR structure and observable tracers
Paris-Meudon/IAS
Lunch
Chair: Gunnar Nyman
Christine Joblin
AstroPAHs: from laboratory experiments
Institut de recherche en
to observational diagnostics
astrophysique et planétologie
Polycyclic aromatic hydrocarbons and dust
Ismael Garcia-Bernete
in star-forming regions and the vicinity of
University of Oxford
AGN: a JWST view
Zeyuan Tang
A computational anharmonic IR database
Center for Interstellar Catalysis,of nanosilicate clusters at astrochemicallyAarhus University
relevant temperatures
Karine Demyk
Temperature-dependent optical propertiesof dust analogues for the interpretation of
Institut de recherche en
astrophysique et planétologie
astronomical observations
Chair: Kirsten Knudsen
Ralf Siebenmorgen
Dark dust
European Southern Observatory
Tomoko Suzuki
Dust content of galaxies at high redshift
Kavli IPMU
Vladan Markov
Constraining the dust attenuation law in
Scuola Normale Superiore
early galaxies with JWST
Roberta Tripodi
University of Trieste, INAF ALMA view on the dust properties of theOsservatorio Astronomico di
HYPERION QSOs
TriestePoster ﬂash session
Poster session and mingle

19

Tuesday, 26th September, 2023
08:00–09:00
9:00am–
9:30am
9:30am–9:45amITCT

9:45am–
10:00amCT

10:00am–
10:15amCT

10:15am–
11:00amCoﬀee break

11:00am–
11:30amIT

11:30am–
11:45amCT

11:45am–
12:00pmCT

12pm–1:30pm
1:30pm–2pmIT

2pm–2:15pm

CT

2:15pm–2:30pmCT

2:30pm–3:15pmChair: Gunnar Nyman
Stefan Bromley
Assessing the astronomical relevance ofinterstellar nanosilicate dust grains from IR
Institució Catalana de Recerca ispectra: theory, experiment andEstudis Avançats [Barcelona],
observation
Universitat de Barcelona
Sascha Zeegers
Exploring the dust properties in the nearby
ESA - ESTEC
diﬀuse interstellar medium with JWST
Marjorie Decleir
Studying dust grain properties and growthSpace Telescope Scienceby combining extinction and depletion
Institutemeasurements in the Milky Way
Lunch
Chair: Dimitra RigopoulouAnaëlle Maury
What do dust grains look like at the onset
CEA/CNRS AIM, Université Parisof the star and disk formation sequence?
SaclayAngelos NersesianModelling the cold dust in nearby spiral
Ghent University
galaxies with radiative transfer
Elisa Costantini
SRON Netherlands Institute for
The X-ray view of dust in the Milky Way
Space ResearchCoﬀee break

3:15pm–3:45pmIT

3:45pm–4pm

CT

20

Registration
Chair: Karl Gordon
Anthony Jones
Dust evolution between diﬀuse and dense
Institut d’Astrophysique Spatiale
environments — It’s complicated
Meriem El Yajouri
Dust evolution across the Orion bar: new
insights from the JWSTInstitut d’Astrophysique Spatiale
Siddharth Maharana
PASIPHAE Survey: Large opticalSouth African Astronomical
polarimetric sky survey for dust cloud andObservatory
magnetic ﬁeld tomography
Christian Kranhold
Astrophysical Institute andSmall amounts of iron(II) sulphides canUniversity Observatory,
signiﬁcantly aﬀect the SEDs ofFriedrich-Schiller-University
circumstellar disks
Jena

Chair: Wouter Vlemmings
Francois Menard
Dust properties from the Lab applied to
IPAG - Institut de Planetologie
young disks: 3D-printing and a Microwave
et d’Astrophysique de Grenoble
Analogy Experiment
The inﬂuence of a clumpy outﬂow andMarie Van de Sandecompanion star on the surface
University of Leeds
composition of AGB dust

4pm–4:15pm

CT

4:15pm–
4:30pmCT

4:30pm–4:45pmCT

4:45pm–5pm
5pm–6:30pm
7pm–10pm

Dries Van De Putte
The far-UV-extinction-to-H2 correlation
Space Telescope Scienceand insights from IR emission in
Institute
photodissociation regions
Jun Yang
The Si K edge gas and dust optical depths
Massachusetts Institute of
toward the galactic bulge
Technology
Ekta Sharma
Investigating the Magnetic Fields under
National Astronomicalstellar feedback using dust polarization
Observatories of China
Poster ﬂash session
Poster session and mingle
Astronomy on Tap

Wednesday, 27th September, 2023
9:00am–
9:30amIT

9:30am–9:45amCT

9:45am–
10:00amCT

10:00am–
10:15amCT

10:15am–
10:30amCT

10:30am–
11:15amChair: Elvire De Beck
Martha Boyer
Space Telescope Science
Dust in AGB stars
Institute
Matthias Maercker
The contribution of dust from AGB stars to
Chalmers University of
the ISM
Technology
Susanne Höfner
Stardust: From micro-physics to global
Department of Physics anddynamics
Astronomy, Uppsala University
Leen Decin
Instituut voor Sterrenkunde, KU
Small pieces make up the big story
LeuvenDust millimetre emission in Nearby
Lara Pantoni
Galaxies with NIKA2/IRAM-30m: major
challenges and latest results of the IMEGIN
IAS, Irfu/Dap
Large Program
Coﬀee break

11:15am–
11:45amIT

11:45am–
12:15pm

IT

12:15pm–
12:30pm

CT

Chair: Liv Hornekær
Cornelia Jäger
Laboratory studies on the production andLaboratory Astrophysics Group,
processing of major cosmic dust
Max Planck Institute forcomponents in laboratory
Astronomy, Heidelberg
Ilse De Looze
Supernova dust formation: a
Department of physics andhigh-resolution view with JWST
astronomy, Ghent University
Arkaprabha Sarangi
Modeling dust formation in supernovae in
Niels Bohr Institutethe JWST era[Copenhagen]21

12:30pm–
12:45pmCT

12:45pm–
1:30pm
1:30pm–
6:30pm

Hiddo Algera
Hiroshima University, National
Astronomical Observatory ofJapan

Massive dust reservoirs in normal galaxies
at redshift 7
Lunch1

Excursion to Varberg fortress

Thursday, 28th September, 2023
9:00am–
9:30am
9:30am–9:45am9:45am–
10:00amCT

10:00am–
10:15am

CT

IT

CT

10:15am–
11:00amIT

11:30am–
11:45amCT

1:30pm–2pm
2:00pm–2:30pm2:30pm–2:45pm2:45pm–3pm

1

Coﬀee break

11:00am–
11:30am

11:45am–
12:00pm
12:00pm–
1:30pmChair: Frederic Galliano
Anja Andersen
Dust growth in nearby galaxies
University of Copenhagen
Massimiliano Parente
The z<1 drop of cosmic dust abundance
SISSA, INAF
Joris Witstok
The origin of dust grains within galaxies
Kavli Institute for Cosmology
seen in the ﬁrst billion years of cosmic time
Gina Panopoulou
Constraining ISM dust properties with
Chalmers University ofstellar polarization and dust emission
Technology

CT

Chair: Liv Hornekær
Emmanuel Dartois
Inﬂuence of grain growth on ices
Institut des Sciences
spectroscopic proﬁlesMoléculaires d’Orsay
Sandra Wiersma
Molecular content in Si + C dust growth
IRAP, Université de Toulouse III processes for laboratory astrophysics
Paul Sabatier, CNRS, CNES
Leonardo Testi
From dust to pebbles: revisiting grain
Università di Bologna
growth in protoplanetary disks
Lunch

IT
IT
CT
CT

Chair: Arka Sarangi
Julia Roman-Duval
The nearby universe:A laboratory to study
Space Telescope Science
the cosmic build-up of interstellar dust in
Institutegalaxies
Brandon Hensley
Rethinking the Nature of Dust in the
JPL/Caltech
Diﬀuse ISM
David Gobrecht
Predicting the dust condensation
University of Gothenburg
sequence from a bottom-up perspective
Jessica Sutter
Using JWST Photometry to Determine
University of California [SanWhat Sets the PAH Distribution in Nearby
Diego]
Galaxies

According to what you answered in the poll, wraps are provided after the session.

22

3pm–3:45pm
3:45pm–4:15pm4:15pm–
4:30pmITCT

4:30pm–4:45pmCT

4:45pm–5pmCT

5pm–5:15pm
7pm–11pm

Coﬀee break
Chair: Susanne Aalto
Hiroyuki Hirashita
Dust growth in high-redshift galaxies andAcademia Sinica
its impact on the grain size distribution
Valentin Le Gouellec
Observational constrains on dust grainalignment: from protostellar cores to PDRs
NASA Ames Research Center
Aleksandra Leśniewska
Astronomical Observatory
Observational evidence of morphological
Institute, Faculty of Physics,
quenching in dusty elliptical galaxies
Adam Mickiewicz University,
Dark Cosmology Centre
Ilsang Yoon
Rise and fall of anomalous microwave
National Radio Astronomy
emission in extragalactic star forming
Observatory
regions
Poster and quiz prices
Conference dinner at Wijkanders

Friday, 29th September, 2023
9am–9:30am

IT

9:30am–9:45amCT

9:45am–
10:00amCT

10am–10:15am

CT

10:15am–
11:00am2

Coﬀee break

11:00am–
11:30amIT

11:30am–
11:45amCT

11:45am–
12:00pm
12:00pm–1pm
1pm–5:45pm

Chair: Arka Sarangi
Elisabetta Micelotta
Dust destruction in supernova remnants
Nanoform
Elizabeth Tarantino
The disappearing act: exploring the PAH
Space Telescope Sciencedeﬁcit at low metallicities
Institute
Felix Priestley
Empirical constraints on dust destruction
Cardiﬀ University
in supernova remnants
Interstellar carbonaceous dust erosion
Ko-Ju Chuang
induced by X-rays irradiation of water ice
Leiden Observatory
in star-forming regions
Chair: Frederic Galliano
Le Ngoc Tram
Max Planck Institute for Radio
Astronomy
Florian Kirchschlager
Ghent University

Radiative Torque Disruption and
Implications

From total destruction to complete
survival: Dust in supernova remnants at
diﬀerent evolutionary stages

Conclusion
Lunch2
Excursion to the Onsala Space Observatory

According to what you answered in the poll, wraps are provided after the session.

23

Posters

24#

Presenter

Title

1

Maryam Saberi

ALMA observations of titanium and aluminium bearing
species in Mira

2

C. Zachary Palmer

Alternative dust grain formation: Pathways of formationfrom alane and ammonia

3

Arya M Nair

Collision induced dissociation of water pyrene molecularclusters

4

Miora Andriantsaralaza

DEATHSTAR – Accurate mass-loss-rate estimates for AGB
stars

5

Stefan van der Giessen

Disentangling galaxy and dust evolution mechanisms
through chemical abundances

6

Joseph Nuth

Dust coagulation in oxygen-rich circumstellar outﬂows

7

Minju Lee

Dust content in a z ∼ 2 quiescent galaxy

8

Christina Konstantopoulou

Dust depletion of metals from from the Milky Way to z ∼ 6

9Monica Relano

Dust grain size evolution in local galaxies as a key to understand galaxy evolution

10

Ekta Sharma

Investigating the Magnetic Fields under stellar feedback using dust polarization

11

Petia Yanchulova Merica-Jones

Dust properties and extinction curves in the magellanic
clouds, M31, and M33

12

Pablo Rivière

Dust surface chemistry in the AB Aur protoplanetary disk:
observations and models

13

Elvire De Beck

Dusty feedback from massive stars

14

Romain Basalgète

Experimental diﬀusion of water through porous amorphous
carbon dust analogues

15

Andreas Møller Slavensky

Characterization of Mg-rich silicate clusters in the interstellar
medium16

Jun YangHigh resolution spectra of the Galactic Binary Pulsar 4U
1907+09

17

Ilse De Looze

High-resolution view of the inner circumgalactic medium of
NGC891

18

Karl Gordon

Interstellar dust extinction from the far-ultraviolet to the
mid-infrared

19

Jihye Hwang

Magnetic ﬁeld revealed by polarized dust emission in G28.34

20

Burcu Günay (Karl Gordon)

Mapping the interstellar dust and ice with JWST21

Stefan Andersson

Mechanisms of SiO oxidation and dust formation

22

Marco Palla

Modelling the dust cycle in local discs: unveiling the contribution of dust processes at kpc scales.

23

Tom Bakx

Observations of dust in the epoch of reionization

24

Ramón J. Peláez

Plasma generation and characterization of ‘dense’ and‘ﬂuﬀy’ hydrocarbon cosmic dust analogs

25

Gent Frederick

Project SUPERPIG

26

Joachim Wiegert

Radiative transfer through 3D models of dust clouds around
AGB-stars

27

Szanna Zsíros

Serendipitous detection of the dusty Type IIL SN 1980K with
JWST/MIRI

28

Giovanni Tedeschi Prades

Simulating dust dynamics in SPH and MFM hydrodynamical
simulations

29

Nina Sanches Sartorio

Supernova shocks and dust destruction: what role does theenvironment play?

30

Emelie Siderud

The eﬀect of dust opacities on winds of carbon-rich AGB
stars

31

Thomas Vannieuwenhuyse

Paradigmatic examples for testing models of optical lightpolarization by spheroidal dust

32

Frederick Gent

Supernova dust destruction in the magnetized turbulent ISM

25

Talks abstracts

Monday, 25th September, 2023
PDRs4All: JWST’s view of the Orion Bar
Els Peeters
Monday, September 25

IT

SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043, USA (SETI)
Department of Physics & Astronomy & Institute of Earth and Space Exploration, Western University, London
ON N6A 3K7, Canada
Mechanical and radiative feedback from massive stars drive the evolution of interstellar matter in our Galaxy
and throughout the Universe, from the era of vigorous star formation at redshifts of 1-3 to the present day.
Photo-Dissociation Regions (PDRs), where far-ultraviolet photons from these stars create a largely neutral
but warm region of gas and dust, are ideal laboratories to study these main feedback processes.
In this talk, we present the ﬁrst results of the PDRs4All JWST Early Release Science program. We obtained
JWST NIRCAM and MIRI images and NIRSpec and MIRI IFU data of the Orion Nebula and the proto-typical
PDR, the Orion Bar. We identify and characterize an incredibly rich inventory of spectral features, showcasing
emission of HI and HeI recombination lines, ionic lines tracing the ionized and neutral gas, CI recombinationlines, ﬂuorescence lines of OI and NI, a wealth of H2 rovibrational and rotational lines, as well as CO, CH+
and HD emission lines, and the aromatic infrared bands.
The observations reveal a hyper-structured molecular cloud edge at small spatial scales of 0.1-1” ( 0.00020.002 pc or 40-400 AU at 414 pc). Towards the Orion Bar PDR, a highly sculpted interface is detected withvery sharp edges and density increases very near the ionization front and dissociation fronts. The PDR edge
is very steep and is followed by an extensive warm atomic layer as traced by the Aromatic Infrared Bands(AIBs). The transition to the molecular PDR as traced by H2 is very complex and structured with several
ridges.
The AIB emission displays an incredible richness of proﬁle shapes and subcomponents. The widths of many
AIBs show clear and systematic variations, being narrowest in the atomic PDR template and broadest in the
dissociation fronts. The relative strengths of AIB (sub)components vary across the mosaic with the aliphatic
3.4 um AIB being strongest in the dissociation fronts whereas the aromatic 3.3 um AIB peaks in the atomic
PDR. All AIB proﬁles are characteristic of class A sources, except for the 11.2 um AIB proﬁle deep in themolecular zone, which belongs to class B. We attribute this to the presence of small, more labile carriers in
the deeper PDR layers that are photolyzed away in the harsh radiation ﬁeld near the surface.

26

Dust Grain Properties in the Gas-Rich Absorption Systems of Diverse Galaxies at z<2
Monique Aller
Monday, September 25

CTGeorgia Southern University
Dust grain properties in the interstellar and circumgalactic media of galaxies can be studied using quasar
absorption systems. The galactic dust grains and gas produce absorption features in the spectra of luminous
background AGNs, whose sightlines serendipitously pass through the foreground galaxies. This techniqueallows investigations into the dust grains in gas-rich galaxies with diverse masses, morphologies, andevolutionary histories, and can probe varied internal environments, ranging from the diﬀuse interstellar
medium to dense molecular clouds. We present results from an ongoing program, using archival Spitzer
Infrared Spectrograph (IRS) spectra that cover the 10 and 18 micron silicate features, to investigate dust grainproperties in individual quasar absorption systems at z<2. Our spectral measurements include the peak
optical depth of the 10 micron feature, the ratio of the 10-to-18 micron features, and the shape and breadthof the absorption features, which allow us to constrain the silicate grain compositions, morphologies, andcrystallinities. We summarize our current results about the similarities and diﬀerences between the silicate
dust grains in varied systems, as a function of galaxy properties. We also compare and contrast the galaxy
dust grain properties in two dusty, gas-rich galaxies traced by Damped Lyman-Alpha (DLA) absorption
systems at z=0.4-0.5 in which we detect similar strength silicate dust absorption features, but which show
diﬀerences in the carbonaceous dust, as exempliﬁed by the strength of the 2175 Angstrom feature. We
discuss variations in dust depletions in quasar absorption systems, and present preliminary results from a
JWST GO-Cycle-1 program investigating silicate dust absorption in gas-rich quasar absorption systems at
z of 0.5-1.2 with 2175 A dust absorption features. A better understanding of the diversity of silicate dust
grain properties in individual systems, and the connections between the silicate and carbonaceous dust
grains, in relation to galactic gas properties and internal environment, may inform models of the evolutionof dust and metals in galaxies, as well as observational studies with facilities such as JWST. We acknowledge
support from NASA grants NNX17AJ26G and 80NSSC20K0887, and STScI grants for HST-GO-15092 and for
JWST-GO-02155.

27

The dust population in PDRs: impact on PDR structure and observable tracers
Raphaël Meshaka
Monday, September 25

CT

Sorbonne Université, Observatoire de Paris, Université PSL, CNRS, LERMA, Paris, France
Dust grains play a key role in the physics and chemistry of the Interstellar Medium. They heat the gas
through the photo-electric eﬀect, and therefore inﬂuence the thermal structure of the ISM. They absorb
the UV radiation of stars that dissociate molecules. They also act as catalysts of the formation of molecules
like H2. All these processes depend on the dust population: chemical composition (carboneous, silicatesetc.) and size distribution. Multiple dust population models have been proposed (Mathis et al. 1977, Zubko
et al. 2004, Draine & Li 2007, Compiegne et al. 2011, Jones et al. 2013). These dust population models
propose a various range of grain compositions and size distributions. They have been constrained by dust
IR-emission and UV-extinction in the diﬀuse ISM but, up to now, the impact of these new distributions on
the chemistry and the excitation of the gas has never been tested. Our goal is to ﬁnd a comprehensivemodel of both, able to explain consistently the gas and grain tracers in various environments. Our goal is
to study the link between the dust population and the thermal and chemical structure of PDRs, traced bygas emission lines. We have updated the treatment of dust physics in the Meudon PDR Code (Le Petit et al.
2006) to allow a wide range of possible dust populations to be used in the model, and reﬁned the treatmentof photoelectric eﬀect to account for the eﬀect of grain composition. The Meudon PDR code simulates
the physics and chemistry of PDRs, solving the chemistry of hundreds of species, the radiative transfer, thethermal balance and the excitation of main species. With this new version of the code, we compare the
THEMIS dust population model (Jones et al 2017) with older models (Mathis et al. 1977, Draine & Li 2007),and its impact on the chemical and thermal structure of various environments : diﬀuse ISM, dense andhighly illuminated PDRs such as the Orion Bar, and less excited PDRs such as the Horsehead Nebula. In
addition to this theoretical study, we try to get new constraints on the dust population parameters basedon gas emission lines observed with JWST, especially H2 ro-vibrational lines.

28

AstroPAHs: from laboratory experiments to observational diagnostics
Christine Joblin
Monday, September 25IT

Institut de recherche en astrophysique et planétologie, Université Toulouse III - Paul Sabatier, CNRS :UMR5277, CNES
The interaction of UV irradiation with large carbonaceous molecules, such as polycyclic aromatic hydrocarbons (PAHs), leads to various molecular processes impacting the physical and chemical conditions instar-forming regions [1,2]. Since a complete simulation of these processes in the laboratory is not possible,
models must be developed and their results validated by comparison with observational diagnostics. Thesemodels are based on experimental results and quantum chemistry calculations that provide quantitativevalues for molecular parameters and processes. I will focus on two examples. The ﬁrst is linked to theheating of the gas by thermalisation of the electrons emitted by ionisation, a process known as photoelectricheating. We recently found good agreement between modelled values and observational diagnostics for
PAH charge state and PAH heating eﬃciency [3]. We concluded that PAH ionisation is the primary sourceof neutral gas heating in diﬀuse gas at all scales from star- and planet-forming regions to distant galaxies.
The second aspect is related to radiative cooling and the analysis of aromatic infrared bands (AIBs), in thecontext of their observation by the James Webb Space Telescope with unprecedented sensitivity, spectral,and spatial resolutions [4]. Detailed analysis of AIBs requires taking into account molecular diversity andthe exciting UV radiation ﬁeld. In this context, we are developing the LAIBrary project [5], which aims
to generate a library of detailed synthetic emission spectra of PAHs and related species in a variety ofastrophysical environments, making use of all available molecular information for a realistic representationof the spectral proﬁles. Important molecular parameters in the emission model include the evolution of theinfrared spectrum with temperature [6,7] and the dynamics of infrared cooling in competition with otherrelaxation processes [8,9]. The quantiﬁcation of these parameters is the subject of speciﬁc experiments that
I will present. Ultimately, LAIBrary will enable us to reﬁne our understanding of emitting molecules and use
AIBs as observational diagnostics of physical conditions in astrophysical environments. [1] A.G.G.M. Tielens,
ARA&A 46, 289 (2008); [2] C. Joblin et al., J. Phys. Conf. Ser. 1412, id. 062002 (2020); [3] O. Berné et al., A&A
667, A159 (2022); [4] O. Berné, E. Habart, E. Peeters, et al., PASP 134, id.054301 (2022); [5] https://cosmicpah.irap.omp.eu/ ;[6] C. Pech et al., A&A 388, 639 (2002); [7] S. Chakraborty et al., JPC A 123, 4139 (2019);[8] M. Stockett et al., J. Chem. Phys. 153, 154303 (2020); [9] https://anr.fr/Project-ANR-21-CE30-0010

29

Polycyclic Aromatic Hydrocarbons and dust in star-forming regions and the vicinity of
AGN: a JWST view
Ismael Garcia-Bernete
Monday, September 25

CT

University of Oxford
Nowadays, it is widely accepted that most galaxies undergo an active phase in their evolution. The impactof the energy released by active galactic nuclei (AGN) in the interstellar medium (ISM) of the host galaxy
has been proposed as a key mechanism responsible for regulating star formation (SF). The mid-infrared (IR)is the ideal spectral range to investigate the nuclear/circumnuclear regions of AGN since dust extinction
is signiﬁcantly lower compared to the visible range. Furthermore, it provides unique tracers to study the
AGN-SF connection such as H2 rotational lines, ﬁne structure lines and Polycyclic Aromatic Hydrocarbons(PAHs). PAHs are also a powerful tool to characterize the ISM in diﬀerent environments. Recently, we
presented new JWST/MIRI MRS spectroscopy of three Seyfert AGN in which we compare their nuclear PAH
emission with that of star-forming regions. This study represents the ﬁrst of its kind to use sub-arcsecond
angular resolution data of local luminous Seyferts with a wide wavelength coverage (4.9-28.1 microns). Our
results showed that a suite of PAH features is present in the innermost parts of these Seyfert galaxies. We
found that the nuclear regions of AGN lie at diﬀerent positions of the PAH diagnostic diagrams, whereas
the SF regions are concentrated around the average values of SF galaxies. Furthermore, we ﬁnd that thenuclear PAH emission mainly originates in neutral PAHs while, in contrast, PAH emission originating in thestar forming regions favours small ionised PAH grains. Therefore, our results provide evidence that the AGN
have a signiﬁcant impact on the ionization state and size of the PAH grains on scales of 142-245 pc. This isfundamental since PAH bands are routinely used to measure star-formation activity in near and far SF andactive galaxies. Finally, I will summarise our ongoing JWST work using cycle 1 observations [id. 1670] andand our prospects for cycle 2 [approved program id. 3535] . In particular, I will focus on our recent study
about the survival of PAH molecules in AGN-driven outﬂows.

30

A computational anharmonic IR database of nanosilicate clusters at astrochemically
relevant temperatures
Zeyuan Tang
Monday, September 25

CTCenter for Interstellar Catalysis, Aarhus University
Silicate dust with diﬀerent compositions, sizes and shapes exhibit varied properties that can be probed
by infrared (IR) observations. The interpretation of IR observation depends on spectroscopic data fromlaboratory measurements and/or quantum chemical calculations. Here we build a computational IR databasefor nanosilicate clusters with anharmonic and temperature eﬀects considered. The IR calculations are basedon machine learning driven molecular dynamics, thereby having the accuracy of ab initio methods and acomputational cost comparable to that of classical force ﬁelds. The database contains pyroxene and olivine
nanosilicate clusters with various sizes and temperatures. Such spectroscopic data are helpful for aiding theinterpretation of the upcoming James Webb Space Telescope (JWST) observations and for understanding
the properties of silicate dust grains in the interstellar medium (ISM) and in circumstellar environments.

31Temperature-dependent optical properties of dust analogues for the interpretation ofastronomical observations
Karine Demyk
Monday, September 25

CTInstitut de recherche en astrophysique et planétologie (IRAP) CNRS : UMR5277, Observatoire Midi-Pyrénées,
Université Paul Sabatier [UPS] - Toulouse III, Université Paul Sabatier (UPS) - Toulouse III
A good understanding of the properties of cosmic dust analogues is essential to study the life cycle ofcosmic dust but also to interpret observations of dust-rich environments. As dust is present in astrophysicalenvironments as diverse as interstellar clouds, cold cores, circumstellar envelopes and disks around evolved
and young stars, planetary atmospheres, PDRs, etc., it is crucial to study the properties of dust analogues
over a wide range of physical conditions in terms of temperature, as well as on the widest possible spectral
range.
In this talk I will present the results of experimental studies of the optical properties of silicates dust
analogues at low temperature (10-300K) in the mid to far infrared range (5-1000 microns). The comparisonof these new optical constants, which are key ingredients of cosmic dust models, with those includedin current cosmic dust models will be shown and the impact on astrophysical studies of cold regions instar-forming regions and protoplanetary disks discussed.
I will also present recent results on the optical properties of PAHs as a function of temperature (14-723K) inthe mid-infrared domain (2-25 microns). The aim of this work is to retrieve empirical anharmonic parametersthat characterise the evolution of the IR spectra of PAHs with temperature. These data is mandatory tosimulate the emission of PAHs in a given astrophysical environment and compare the simulated IR spectrawith the astronomical Aromatic Infrared Bands (AIBs), which are currently observed with the James Webb
Space Telescope (JWST).
These fundamental data on silicate analogues are provided to the astronomical community via the STOPCODA
database (https://www.sshade.eu/db/stopcoda) and the Cosmic PAH portal (http://cosmic-pah.irap.omp.eu).

32

Dark Dust
Ralf Siebenmorgen
Monday, September 25ITEuropean Southern Observatory
1) Distance estimates derived from spectroscopy or parallax have been uniﬁed by considering extinction bylarge grains. The addition of such a population of what is called dark dust to models of the diﬀuse interstellar
medium is tested against a contemporary set of observational constraints. By respecting representative
solid-phase element abundances, the dark dust model simultaneously explains the typical Milky Way
wavelength-dependent reddening, extinction, and emission of polarised and unpolarised light by interstellar
dust particles between far-UV and millimetre wavelengths. The physical properties of dark dust were derived.
Dark dust consists of micrometre-sized particles and provides signiﬁcant wavelength-independent reddening
from the far-UV to the near-infrared. Light absorbed by dark dust is re-emitted in the submillimeter region
by grains at dust temperatures of 8-12K. This very cold dust has frequently been observed in external galaxies.
Optical constants for amorphous silicate dust analogous were investigated and mixing 3% in mass of Mg0.8
Fe2+
0.2 SiO3 to MgO0.5 SiO2 , a good ﬁt to the data of the general ﬁeld of the diﬀuse ISM was derived that
can accommodate up to 5-10% of the mass in dark dust. The additional dimming of light by dark dust is
unexplored when supernova Ia light curves are discussed and in other research.
2) The nature of dust in the diﬀuse interstellar medium can be best investigated by means of reddening
curves where only a single interstellar cloud lies between the observer and the background source. Publishedreddening curves often suﬀer from various systematic uncertainties. We analyse a total of 110 sightlines
toward OB stars with 174 reddening curves. We exclude stars with composite IUE of multiple, with uncertain
spectral type photometric variability, and inconsistent parallaxes. In total, 53 stars pass the rejection andwere included in the high-quality Milky Way reddening curve sample.

Dust content of galaxies at high redshift
Tomoko Suzuki
Monday, September 25ITKavli IPMU
Dust and gas contents in galaxies are key physical quantities to understand the evolution of galaxies via starformation, gas outﬂow, and gas inﬂow. Sub-mm/mm observations over past decades revealed the dust andgas properties of not only dusty galaxies but also UV/optical selected galaxies at z > 1, which allows us toinvestigate the dust properties of diﬀerent types of galaxies at high redshift. One of the missing pieces of
information is the chemical conditions of ISM in these galaxies. Whereas the formation of dust is considered
to be closely related to the gas-phase metallicity, the relation between the two quantities has not been fully
investigated yet for galaxies at high redshift. In this talk, I will share our observational study about the dust
(and gas) content and gas-phase metallicity of star-forming galaxies at z > 3 and more recent observational
studies on the dust properties of high redshift galaxies.

33

Constraining the dust attenuation law in early galaxies with JWST
Vladan Markov
Monday, September 25

CT

Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa - Italy
Constraining the dust attenuation law and its evolution over cosmic time is essential for understanding
the properties of the interstellar dust (dust content, grain size distribution, chemical composition) andthe dust production mechanisms, along with the global properties of early galaxies. The current standard
approach of "a priori" assuming a dust attenuation law based on local sources may not be appropriate forhigh-redshift galaxies.
I will present a new tool, based on the Spectral Energy Distribution (SED) ﬁtting, which allows for thesimultaneous characterization of the dust attenuation properties and global parameters of galaxies without
any prior assumption on the dust law. The advantage of using this robust model, is its capability to recover
the dust attenuation properties reddened by any well-known, or potential new dust curve that might exist
at the Epoch of Reionization (EoR). We apply our new tool to a sample of star-forming galaxies at the EoR,
using James Webb Space Telescope (JWST) observations. This approach, along with the new JWST data,
oﬀers means of constraining the dust properties of a large sample of galaxies at the EoR.

ALMA view on the dust properties of the HYPERION QSOs
Roberta Tripodi
Monday, September 25

IT

University of Trieste
INAF - Osservatorio Astronomico di Trieste
Dust properties are key elements to understand the assembly and nature of the ﬁrst QSOs at the Reionization
Epoch. Indeed a reliable and accurate determination of the dust properties, through the analysis of thecontinuum emission, enables us to determine the star formation rate of the QSO’s host galaxy. However, dust
masses and temperatures are often determined with huge uncertainties relying only on single-frequency
continuum detections. I will present results on the dust properties of some z>6 QSOs, belonging to the
HYperluminous QSOs at the Epoch of ReionizatION (HYPERION) sample (Zappacosta+23). HYPERION is a 2.4
Ms XMM-Newton Multi-Year Heritage Programme targeting the titans among z > 6 QSOs, powered by thefastest growing and most massive Super Massive Black Holes (SMBH) at their epoch, and likely assembled
from the largest black-hole (BH) seeds, or experienced peculiar, possibly supercritical, mass accretion
histories. We successfully proposed and obtained high-frequency ALMA observations for HYPERION QSOs,
which enabled us to probe the peak emission of the cold dust spectral energy distribution and therefore toconstrain the star formation rate of the QSO’s host galaxies with very high precision (Tripodi+23, Tripodi inprep.). The ﬁnal goal will be to have a broader picture of the dust properties of high-z QSOs and to discuss
the evolutionary scenario of these objects.

34

Tuesday, 26th September, 2023

There and back again — Dust evolution between diﬀuse and dense environments — It’scomplicatedAnthony Jones
Tuesday, September 26

IT

Institut d’Astrophysique Spatiale (IAS Orsay)
Within the framework of The Heterogeneous dust Evolution Model for Interstellar Solids (THEMIS) I will
discuss what we currently understand about the evolution of dust in the transition between low and highdensity regions. This evolution involves changes in the dust structural and chemical properties, encompassing: dust growth via carbonaceous (a-C:H) and icy mantle accretion, nanoparticle sweep-up or dust
aggregation, mantle disruption, coagulated grain disaggregation, (E)UV photo-processing, radiation pressure
sorting or segregation, ... Dust evolution is accelerated in the high density, extremely irradiated regions nearstars (star formation regions, PDRs and CS discs) and is driven by gas-grain, grain-grain and grain-photon
interactions. These processes can occur sequentially, co-spatially and/or co-temporally with changes in thelocal physical conditions (density, temperature, ionisation state, ISRF, ...) and occur in both the forward
or constructive and reverse or destructive senses. The primary observational evidence for these evolutionary processes includes: UV to IR extinction variations, changes in the UV extinction steepness, the(dis)appearance of nanoparticle extinction and emission, cloud- and core-shine (C-shine), carbon and oxygen
depletion variations, ... In order to study dust evolution we therefore need to understand how its size,
structural & shape distribution, chemical composition and charge state respond to the local environment.

Dust Evolution across the Orion Bar: new insights from the JWST
Meriem El Yajouri
Tuesday, September 26

CT

Institut d’Astrophysique Spatiale (IAS)
The interstellar medium (ISM) is a complex and dynamic environment that plays a crucial role in the formationof stars and planets. Dust is a fundamental component of the ISM, and its properties, including composition,
size distribution, abundance, and optical properties, evolve in response to changes in the local environment,such as radiation ﬁeld and density. In this study, we use data from the JWST program "PDRs4All" [1] to
explore the evolution of dust properties in the Orion Bar, a strongly FUV-irradiated photon-dominatedregion (PDR) at the interface between cold, dense molecular clouds and hot, ionized regions. We model thedust emission in the Orion Bar in seven photometric bands using THEMIS dust model [2] and SOC [3], a 3D
radiative transfer code that takes into account variations in the local physical conditions: geometry, density,and irradiation. The JWST allows us for the ﬁrst time to spatially resolve the steep density gradient at theilluminated edge of the PDR. By considering both carbonaceous nanograins and submicronic grains acrossthe PDR, we derive unprecedented constraints on the properties of the dust grains across the Orion bar.
This study provides new insights into the evolution of dust properties in PDRs and demonstrates the powerof JWST observations to spatially resolve these regions.

35

PASIPHAE Survey: Large optical polarimetric sky survey for dust cloud & magnetic ﬁeld
tomography
Siddharth Maharana
Tuesday, September 26

CTSouth African Astronomical Observatory
PASIPHAE (Polar-Areas Stellar Imaging in Polarization High Accuracy Experiment) project, scheduled to begin
in 2023, aims to create the ﬁrst large stellar polarization map of the sky, spanning thousands of square
degrees in the galactic polar regions. This new catalog will enable creation of magnetic ﬁeld and dust cloud
tomography map of the galactic polar regions using stellar polarimetry and GAIA stellar distances as tools.
Two WALOP (Wide-Area Linear Optical Polarimeter) instruments, to be mounted on 1 m class telescopes inSouth Africa and Greece are being developed to measure the linear polarization of stars up to 16 magnitudein SDSS-r broadband with 0.1 % accuracy. WALOPs have been designed to operate with the combined
capabilities of one-shot linear polarimetry, low polarization systematic (< 0.05%) and a large ﬁeld of viewof 35× 35 arcminutes, making it a unique astronomical instrument. In a single measurement, WALOPs canmeasure the linear Stokes parameters I, q and u in the SDSS-r broadband and narrowband ﬁlters between
500- 700nm. For each exposure, four images of the full ﬁeld corresponding to polarization angles of 0, 45,
90 and 135 degrees will be generated and by carrying out diﬀerential photometry on these images, theStokes parameters can be obtained. Some critical challenges in designing WALOPs include- (a) correcting
for the spectral dispersion introduced by Wollaston prisms used as analysers, (b) large vi- gnetting andthroughput loss for oﬀ-axis ﬁeld objects, and (c) large instrumental polarization. We have developed thecomplete instrument design including the optical and optomechanical design for WALOPs which overcomes
these challenges and are expected to meet the design goals. Both WALOPs are in advanced phases ofassembly and integration and are scheduled for commissioning in 2023. I will present the PASIPHAE project
details, how its requirements drive the technical goals of WALOP instruments, and our eﬀorts in their designand development.

36

Small amounts of iron(II) sulphides can signiﬁcantly aﬀect the SEDs of circumstellar
disks
Christian Kranhold
Tuesday, September 26

CT

Astrophysical Institute and University Observatory, Friedrich-Schiller-University Jena
Iron(II) sulphides are well-known environment sensitive inorganic compounds of iron and sulphur in our solar
system. They range from centimetre-sized macro-crystals down to nanoparticle inclusions in GEMS, IDPs,
meteorites, asteroids and comets. Only a few studies claim to have detected extrasolar iron(II) sulphides,
for example identifying troilite (FeS) in planetary nebulae. We study the inﬂuence of Fe/S ratios on the SEDsof silicate-rich circumstellar disks, including temperature dependencies of free-charge-carrier characteristics
and phonon bands. We show that the iron-to-sulphur ratio plays a crucial role in the detection of iron(II)sulphides. As a result, adding just small amounts of iron(II) sulphides to a pure silicate circumstellar disk
would increase its ﬂux in the middle- and far-infrared. Both troilite (FeS) and pyrrhotites (Fe1−x S, x=0... 0.125), cause absorption eﬃciencies to increase signiﬁcantly in the visible, near- and mid-infrared incomparison to the far-infrared. There, the troilite phonon bands have a small impact and the pyrrhotite
addition does not change the form of the spectrum. Future infrared-space missions could directly detect
troilite by phonon bands, whilst the metal-like ‘featureless’ behaviour of pyrrhotites would only inﬂuence
the relative SED ﬂux. Such observations would signiﬁcantly improve our understanding on the compositionand history of circumstellar disks.

37

Assessing the astronomical relevance of interstellar nanosilicate dust grains from IR
spectra: theory, experiment and observation
Stefan Bromley
Tuesday, September 26

IT

Institució Catalana de Recerca i Estudis Avançats [Barcelona] (ICREA)
Universitat de Barcelona (UB)
Silicates are ubiquitously found as small dust grains throughout the universe. These particles are frequently
subject to high-energy processes in the diﬀuse interstellar medium (ISM), where they are broken up into
many ultrasmall silicate fragments. The resulting species will likely range in size from the atomic scale (e.g.
metal ions) to molecular and nanoscales (e.g. nanosilicate grains with a few 10/100s of atoms). Due to their
reduced size, even if such grains constitute a small mass percentage of the dust budget, they should form ahighly numerous population with potential for seeding dust (re)growth and involvement in astrochemical
processes. Here, we assess the structures, spectroscopic properties and astronomical relevance of suchnanosilicates by employing accurate theoretical modelling [1] and cluster beam experiments [2]. We highlightthe potential role of abundant nanosilicates in: i) the anomalous microwave emission [3], ii) astrochemistry[4], iii) oxygen depletion [2], and iv) dust (re)formation [2] in the ISM. Finally, by considering the distinct
infrared (IR) spectra of nanosilicates with respect to that of larger silicate grains, we predict that nanosilicate
populations should be observable with the James Webb Space Telescope (JWST). These predictions will
be compared with our latest JWST observations considering lines of sight through the diﬀuse ISM [5]. 1.
Structure and Properties of Nanosilicates with Olivine (Mg2 SiO4 )N and Pyroxene (MgSiO3 )N Compositions,A. Macia Escatller, Tomas Lazaukas, S. M. Woodley, S. T. Bromley, ACS Earth and Space Chemistry (2019) 3,
2390. 2. Cluster Beam Study of (MgSiO3 )+-Based Monomeric Silicate Species and Their Interaction with
Oxygen: Implications for Interstellar Astrochemistry, J. Mariñoso Guiu, B-A. Ghejan, T. M. Bernhardt, J. M.
Bakker, S. M. Lang, S. T. Bromley, ACS Earth and Space Chemistry (2022), 6, 2465. 3. Assessing the viabilityof silicate nanoclusters as carriers of the anomalous microwave emission: a quantum mechanical study, A.
Macia Escatller, S. T. Bromley, Astronomy & Astrophysics (2020) 634, A77. 4. Trends in the adsorption andreactivity of hydrogen on magnesium silicate nanoclusters, I. Oueslati, B. Kerkeni, S. T. Bromley, Physical
Chemistry Chemical Physics (2015) 17, 8951. 5. Illuminating the dust properties in the diﬀuse ISM with JWST,
Zeegers et al., 2021, JWST Proposal. Cycle 1, ID. 2183.

38

Exploring the dust properties in the nearby diﬀuse interstellar medium with JWST
Sascha Zeegers
Tuesday, September 26

CT

ESA - ESTEC
The diﬀuse interstellar medium plays an essential role in regulating the energy balance of galaxies, byprocessing starlight and driving molecule formation. It contains the input ingredients of dense star forming
clouds and, consequently, of new stars and planets. Therefore, it is important to understand the properties,
formation and evolution of this dust. However, we lack a fundamental understanding of the dust cycle ingalaxies and its main elemental building blocks: H, C, O, Si, Mg, and Fe. The wavelength coverage, sensitivity,and spectral resolution of JWST at near- and mid-infrared wavelengths enables us to measure the abundanceand determine the composition of the major C and O dust reservoirs in the Milky Way’s diﬀuse interstellar
medium. By observing reddened O and B stars in the nearby diﬀuse interstellar medium we are able toobserve dust features in the spectra of these stars that will reveal the dust properties along the line of sight.
In this talk we present the ﬁrst exciting results of Webb Investigation of Carbon Silicates and Ices (WISCI)
project in which we study dust along the line of sight of twelve OB stars, using JWST MIRI and NIRCam (GOcycle 1 program id 2183) and HST STIS (cycle 30 program id 17078) spectroscopy. We will show how a global
multiwavelength view (FUV - MIR) provides a much deeper understanding of the dust properties in thediﬀuse interstellar medium.

39

Studying dust grain properties and growth by combining extinction and depletion measurements in the Milky Way
Marjorie Decleir
Tuesday, September 26

CTSpace Telescope Science InstituteInterstellar dust grains come in diﬀerent sizes and compositions, depending on the environment in which
they reside. An indirect, quantitative way to measure the chemical composition of dust grains is via dust
depletions: The dust abundance of an element (such as C, Si, Mg, Fe and O) in a given sightline can bederived by comparing the observed gas abundance to a reference total (gas + dust) abundance of thatelement in that particular sightline. In addition, depletion measurements can help us determine which
grain growth mechanism dominates, as accretion of gas particles onto existing dust grains will aﬀect the gas
and dust abundances, while coagulation of smaller dust grains does not change the atomic abundances. In
our ongoing HST GO program, we are using UV spectra to measure dust depletions in a sample of Milky
Way sightlines, that span a range of environments (as traced by their molecular hydrogen fraction). This
will pose strong constraints on the detailed dust grain composition and how it varies between diﬀerent
environments, which will allow us to directly assess the accuracy of existing dust grain models. Furthermore,
we will combine these depletion measurements with literature UV extinction curves, as well as NIR-MIR
extinction curves that will soon be measured with our JWST GO program, for the same sightlines. This
will enable us to correlate the properties of the extinction features (such as the UV bump, the 3.4 micron
carbonaceous feature and the 10 and 20 micron silicate features) to the atomic abundances and ratios, andas such reveal the carriers of these features. In this talk, I will explain the goals of our synergistic HST-JWST
project, and highlight our preliminary results towards constraining dust grain properties and their variationin the Milky Way.

40

What do dust grains look like at the onset of the star and disk formation sequence ?
Anaëlle Maury
Tuesday, September 26

IT

Unité Mixte CEA/CNRS AIM, Université Paris Saclay
The formation and properties of exoplanetary systems is a fascinating question, which has been at the heartof our quest to deﬁne mankind and the conditions for life to develop in a broader context. Observations
suggest there should be billions of planets in our Galaxy alone. What are the physical process that makeplanet formation so likely ? Which local conditions are required to transform the stardust of the interstellar
medium into pebbles around young stars, and grow these further into planets ? Investigating the dust
evolution along the star formation sequence is key to provide a complete picture of the planet formation
scenario.
Moreover, the properties of dust grains in star-forming structures are crucial because they regulate someof the key physical processes at work while the star and its disk are being built. For example, it has beenshown that the amount of small grains is a key parameter to set the eﬃciency of magnetic process allowing
to regulate the angular momentum of the infalling material during protostellar mass build-up, as they may
be the main charge carriers in such environments.
In this talk, I will provide a global outlook on the progresses made in the recent years to investigate theproperties of dust around the youngest stellar objects, embedded protostars, and the pristine circumstellar
disks observed around them. I will put a special emphasis on describing some puzzling observations andtheir comparison to state-of-the-art physical models of protostars. I will discuss how these data suggest theneed to develop revised dust models, in an attempt to describe the early evolution of dust grains towards
future planetary seeds.

41Modelling the cold dust in nearby spiral galaxies with radiative transfer
Angelos Nersesian
Tuesday, September 26CT

Ghent University
Cosmic dust grains are one of the fundamental ingredients of the interstellar medium (ISM). Despiteof their limited contribution to the total mass budget, dust grains play a signiﬁcant role in the physicaland chemical evolution of galaxies. Over the past decade, our knowledge on the cosmic dust in nearby
galaxies has increased substantially thanks to the availability of observational data from UV to far-infrared
wavelengths. However, one part of the spectrum, the mm range, has largely remained unexplored. We aim
to take advantage of the new, high-resolution data in the mm range observed with the NIKA2 instrument.
Combining these new observational data with our radiative transfer framework, would allow us to accurately
model the interplay between starlight and dust in a sizeable sample of spatially-resolved nearby galaxies. I
will present the methodology of our dust radiative transfer modelling and its application to a small group of
face-on spiral galaxies. I will highlight which modelling steps need to be improved, and how the new NIKA2
data would allow us to ﬁrmly characterize the physical properties of the very cold dust (<15K), as well as toquantify the importance of diﬀerent emission mechanisms in the mm.

The X-ray view of dust in the Milky Way
Elisa Costantini
Tuesday, September 26

CT

SRON Netherlands Institute for Space Research
Astronomical Institute Anton Pannekoek
In the last years tremendous improvement in our understanding of interstellar dust (ID) in the X-rays has
been made. Thanks to accurate modelling, derived from new dust laboratory measurements, X-rays proved
to be a powerful tool to investigate the chemistry, size and crystallinity of dust along our line of sight. By
studying the light absorbed by bright background X-ray sources, several dust environments, from diﬀuse todense regions, can be investigated. More often than not, X-ray studies challenged our understanding of dust
formation and structure (e.g. Zeegers et al. 2017, 2019; Rogantini et al. 2019, 2020; Psaradaki et al. 2020,
2022, Costantini & Corrales 2022). X-rays are able indeed to provide also complementary information withrespect to longer wavelength. In this contribution we will review the state-of-art from the X-ray point ofview and the new science window that upcoming X-ray missions (e.g. XRISM, to be launched in Aug 2023)
will open.

42

Dust Properties from the Lab applied to young disks: 3D-printing and a Microwave
Analogy ExperimentFrancois Menard
Tuesday, September 26

ITIPAG- Institut de Planetologie et d’Astrophysique de Grenoble
To set the stage of this review, I will very brieﬂy present some of the latest observational attempts to reveal
dust properties in protoplanetary disks. Dust sizes and chemical composition of dust in disks have beenstudied abundantly in the past via, e.g., spectral energy distributions and near- and mid-spectroscopy. In
this review I will place a special emphasis on recent attempts to highlight the particle shapes instead. Thiscan be done via the measurements of their scattering properties, i.e., intensity and linear polarisation phasefunctions, from the optical to the millimetric wavelength range. These recent advances are particularlyinteresting to connect the dust properties in disks to the dust evolution and growth mechanisms, a better
understanding of which is needed to advance our knowledge of the ﬁrst stages of planet formation. To
reveal the full meaning of these "phase functions", it is necessary to compare them with a database ofthe "measured" or "calculated" scattering properties of complex dust particles, be them irregular, withrough surfaces, or of fractal nature. I will therefore spend most of the review to present recent eﬀorts tomeasure the scattering properties of complex dust particles from Laboratory Experiments. In particular I
will describe the Micro-Wave Analogy experimental set-up we have been developing recently. I will describe
the experimental set-up itself as well as the methods we have developed to prepare relevant dust analogs
via 3D-printing. This implies using/developing "printable" materials with relevant refractive indices for
astronomical dust. I will wrap up by describing recent measurements and results and compare them withthose from purely numerical methods.

43

The inﬂuence of a clumpy outﬂow and companion star on the surface composition of
AGB dust
Marie Van De Sande
Tuesday, September 26

CT

University of Leeds
The asymptotic giant branch (AGB) phase of stars of low-to-intermediate initial mass is characterised bystrong mass loss via a stellar wind, which is thought to be propelled by a pulsation-enhanced dust-driven
outﬂow. The stellar wind creates an extended circumstellar envelope (CSE), that is a rich astrochemicallaboratory: close to 100 molecules have been detected in CSEs, together with various types of newly-formed
dust. Thanks to their outﬂows AGB stars are important contributors to the chemical enrichment of theinterstellar medium (ISM), contributing about 70% of the total stellar dust production rate. Understanding
the dust evolution cycle in the ISM crucially depends on better understanding the composition of its
starting point, i.e., stellar dust. Observations of AGB outﬂows continue to reveal their complexity. Sphericalasymmetries are ubiquitous and thought to be caused by binary interaction. Additionally, dust-gas chemistry
plays a role in higher density outﬂows, accreting gas-phase material onto the dust. We have combined ourprevious chemical model developments into the most chemically and physically advanced chemical kinetics
model of AGB outﬂows to date. The model includes a porous density distribution, comprehensive dust-gas
chemistry, and internal UV photons originating from a close-by companion star. The photoprocessing ofvolatile complex ices into refractory organic material is also included. We disentangle how the size andcomposition of the ice mantle and refractory organics depends on the clumpiness of the outﬂow, thepresence of a companion star, and the grain size distribution of the dust. In addition to studying the surface
chemistry and the composition of the ices and refractory material on the dust’s surface, we also identify
gas-phase tracers of dust-gas chemistry. We present suites of molecules to retrieve the speciﬁc physical andchemical properties of observed outﬂows and the evolution of the surface composition of the dust. These
will help guide the next suite of observations of both the gas phase and the ice phase and provide valuable
tools to better understand the input of stellar dust to the ISM.

44

The far-UV-extinction-to-H2 correlation and insights from IR emission in photodissociation regions
Dries Van De Putte
Tuesday, September 26

CTSpace Telescope Science InstituteIn a recent publication, we discovered a strong linear correlation between the far-UV rise of galactic extinction
curves, and the column density of H2. This extinction does not scale with HI, meaning that the carrier of the
far-UV rise and H2 are co-spatial. While the exact interpretation still open, one option is that the surfaces ofthe far-UV rise grains are directly responsible for the formation of H2. Alternatively, H2 and the grains inquestion could be related because their survival depends on similar shielding requirements.
A clue to the interpretation of this H2-extinction correlation, is likely found in photodissociation regions(PDRs). These regions are at the border between atomic and molecular hydrogen gas, where interstellar
clouds are illuminated by UV-bright stars, showing a rich and bright spectrum of IR bands. We present
spatially resolved IFU spectroscopy of the Orion Bar from the PDRs4All program, the Horsehead, and NGC
7023 (GTO program, data acquisition scheduled). An initial result for the Orion Bar NIRSpec data, is that the
3.4 micron band has a component which appears primarily where excited H2 lines are bright. We will obtain
NIRSpec data for the other two objects soon. This clue, the presence or lack of other correlations, andthe previously discovered far-UV-extinction-H2 relationship, can serve as new constraints for dust models
addressing the far-UV rise.

45

The Si K Edge Gas and Dust Optical Depths Toward the Galactic Bulge
Jun Yang
Tuesday, September 26

CT

Massachusetts Institute of Technology
Knowledge of the dust content in interstellar matter is important to our understanding of the composition andevolution of the interstellar medium. The Chandra High Energy Transmission Grating (HETG) Spectrometer
provides a unique opportunity to measure X-ray absorption of interstellar dust and its compositions throughthe X-ray edge absorption structure. We measure gas and dust optical depths at Si K toward nine bright
low-mass x-ray binaries in the Galactic Bulge with very high-precision and pileup-free spectra. We include alikely instrumental feature aﬀecting the Si K edge structure in our analysis. While gas optical depths growconsistently with broadband hydrogen-equivalent columns, the dust optical depths do not. Calculations
including dust self-shielding show that the observed dust optical depths can be explained by variations in dust
grain columns between various lines of sight. At least three grain column regimes can be identiﬁed toward
the Galactic Bulge. While grain sizes deﬁne the self-shielding eﬀect, variations in grain size distributions do
not seem relevant. This shows that the gas-to-dust optical depth ratio toward sources in the Galactic Bulge
is not homogeneous. The dust optical depths also roughly correlate with molecular hydrogen columns.
Lowly ionized Si K contributions toward the Galactic Bulge were detected but are very small. We also ﬁnd Si
xiii absorption with velocity widths of 800–1100 km s-1, which we attribute to the circumbinary medium.

Wednesday, 27th September, 2023

Dust in AGB Stars
Martha Boyer
Wednesday, September 27

ITSpace Telescope Science InstituteAsymptotic Giant Branch (AGB) stars have long been thought to be a source of dust injection into theInterstellar Medium. In the Spitzer era, several studies surveyed nearby galaxies in the infrared (IR) to
determine AGB dust composition and dust production rates, with particular focus on AGB stars in the
Magellanic Clouds. I will summarize those and other recent studies of AGB dust, and discuss recent/upcoming
results from the JWST. JWST is able to probe far more distant galaxies than were previously reachable in theIR, expanding investigations to lower and higher metallicities and providing more complete samples of thisshort-lived, and thus rare, stellar phase.

46

The contribution of dust from AGB stars to the ISM
Matthias Maercker
Wednesday, September 27

CTChalmers University of Technology
The detection of pre-solar grains in meteorites shows that at least some of the dust from asymptotic giant
branch (AGB) stars survives the transition into the ISM. It is likely that these grains act as seeds for further
dust-growth in the ISM leading to the ﬁnal observed interstellar dust. I will present a detailed analysisof the dust emission observed with Herschel/PACS at 70 and 160 micron towards wind-ISM interaction
regions around a sample of 22 carbon and oxygen-rich AGB stars. My results show that there is a tendency
for the grains in the wind-ISM interaction regions to be relatively large (approx. 2 micron), while several
uncertainties that aﬀect commonly made basic assumptions on interstellar dust (e.g., composition andmorphology) become obvious. This may have severe implications for our understanding of interstellar dust
and their eﬀect on the chemical evolution of the ISM. Interstellar dust grains contribute fundamentally tothe chemical evolution of the ISM. They provide surfaces for molecular chemistry, can incorporate complex
molecules, and shield the molecules from destruction by the interstellar radiation ﬁeld. However, the dust
observed in the ISM is distinctly diﬀerent from the dust observed in the circumstellar envelopes aroundevolved stars. The physical conditions in the regions where the stellar wind interacts with the ISM may leadto signiﬁcant reprocessing of the grains, strongly aﬀecting properties like the size, structure, geometry, andcomposition of the grains. Our lack of understanding aﬀects our knowledge of the chemical feedback to
the ISM from evolved stars, and the origin of the cycle of dust in the ISM. We calculated 3-dimensionalradiative transfer models of the thermal dust emission to constrain the geometry of the interaction regions,the total dust masses and temperatures, and the properties of the dust grains. The results show a pathforward in investigating the origin of interstellar dust, the cycle of dust in galaxies, and the eﬀect on thechemical evolution of the ISM.

Stardust: From micro-physics to global dynamics
Susanne Höfner
Wednesday, September 27

CT

Department of Physics and Astronomy, Uppsala University
Dust is a critical agent in cool giant stars, driving their winds through radiation pressure. The resulting heavy
mass loss dominates the evolution of these stars, turning them into white dwarfs. The local conditionsin the close stellar environment, set by convection, pulsation and radiation, determine where and whattypes of dust can form. The properties of the dust grains, in turn, aﬀect the dynamical structure of theouter atmosphere and wind. In our detailed radiation-hydrodynamical models we investigate this interplayof micro- and macro-scale processes, and how it shapes the complex morphology and dynamics of theemerging stellar wind around AGB stars. In this contribution we discuss recent results, including gradual Feenrichment of wind-driving silicate grains, and the ﬁrst global 3D RHD models of AGB stars with dust-driven
winds.

47

Small pieces make up the big story
Leen Decin
Wednesday, September 27

CT

Instituut voor Sterrenkunde, KU Leuven (KUL)
Small pieces make up the big story. And these small pieces are here interstellar molecules, Polycyclic
Aromatic Hydrocarbon (PAH) molecules. And the big story is the Universe, galactic and extra-galactic.
PAH molecules provide a tool to probe macroscopic aspects of the Universe, and vice-versa oﬀers theharsh environment of space unique insight in microscopic processes controlling formation and destruction,
excitation and relaxation of individual molecules. PAHs are believed to play a signiﬁcant role in the processof dust growth and formation in the interstellar mediums. Under certain conditions, PAHs can aggregate andform small clusters or nanoparticles, which can act as seeds for the subsequent growth of larger dust grains.
PAH molecules are responsible for infrared emission features in a large variety of (inter)stellar environments,
including HII regions, young stellar objects, post-Asymptotic Giant Branch stars, planetary nebulae, nuclei ofgalaxies, and ultraluminous infrared galaxies. They lock up some 10% of the elemental carbon, and together
with carbon monoxide (CO) form the main molecular reservoirs of carbon. As such, the story of interstellarorganic chemistry is undeniably linked with the story of PAH molecules. In this lecture, I will review someold and new knowledge on PAH molecules and their role in dust formation. I will touch on the question
whether only the most stable PAH molecules survive the harsh conditions of hot spots in photodissociation
regions, or whether we should interpret this survival of the ﬁttest in a Darwinian way, i.e. "It is not thestrongest species that survives, nor the most intelligent, but the one most responsive to change". I willend with a - maybe controversial - example based on a multi-disciplinary eﬀort, combining new laboratory
experiments, quantum chemical calculations, and astrophysical modelling that shows how buckyball-metal
complexes can be promising carriers of unidentiﬁed infrared emission bands.

48

Dust millimetre emission in Nearby Galaxies with NIKA2/IRAM-30m: major challenges
and latest results of the IMEGIN Large Program.
Lara Pantoni
Wednesday, September 27

CT

IAS, Irfu/Dap
The millimetre wavelength domain of the spectral energy distribution of galaxies is one of the least explored
wavelength domains, yet it contains emission from three fundamentally important physical processes:
thermal emission from dust, free-free emission from ionized gas and synchrotron emission from relativistic
charged particles moving in the galactic magnetic ﬁeld. The NIKA2 camera (IRAM-30m telescope), observing
at 1 mm and 2 mm, provides critical observations for input into comprehensive SED models and allows us
to: 1) disentangle spatially resolved galaxy spectral energy distribution from dust contribution, free-freeand synchrotron emission; 2) constrain the evolution of the dust-to-gas mass ratio within galaxies, which
provides a direct link to the chemical evolution of galaxies and the reservoirs for dust production; 3) study
the microscopic properties of dust, i.e. constraints on millimetric opacity; 4) study the sub-millimetre excess
in galaxies, the origin of which is still unknown. These are some of the main objectives of the IMEGIN Large
Program (Interpreting the Millimetre Emission of Galaxies with IRAM-NIKA2; PI S. Madden), targeting 22
nearby galaxies in the millimetre continuum regime with the NIKA2 camera. The NIKA2 millimetre data,
combined with a suite of multi-wavelength observations from mid-infrared to radio, including CO and HI,
allow us to model the IR-to-radio SED and put constraints on interstellar medium and dust grains propertiesof galaxies. Our SED analysis (performed globally and locally) makes use of the state-of-the-art hierarchicalbayesian ﬁtting code HerBIE with the prescriptions of the dust evolution model THEMIS, which is anchoredto the laboratory-measured properties of interstellar dust analogues. During my talk, I will focus on the
major challenges linked with data post-processing and uncertainty propagation, large-scale emission ﬁltering
in NIKA2 maps (due to atmosphere subtraction during the data reduction process) and I will present thelatest scientiﬁc results.

49

Laboratory studies on the production and processing of major cosmic dust components
in laboratory
Cornelia Jäger
Wednesday, September 27

IT

Laboratory Astrophysics Group, Max Planck Institute for Astronomy, Heidelberg, and Institute of Solid State
Physics, Friedrich Schiller University Jena
Refractory dust grains comprising silicates, oxides, metals, sulﬁdes, and carbon condense in circumstellar
environments around evolved stars and in the interstellar medium at temperatures ranging from 10 K up to
about 2000 K. The dust attests its existence by the interstellar extinction and polarization, IR emission andabsorption spectra, and elemental depletion patterns. Dust grains are constantly processed or even destroyed by energetic photons, ions, and shocks in nearly all astrophysical environments including the diﬀuse
interstellar medium, molecular clouds, and protoplanetary disks. In various astrophysical environments,
dust grains are covered by molecular ices and therefore, contribute or catalytically inﬂuence the chemical
reactions in these layers. Eventually, dust is the basic material for the formation of planets, asteroids, andcomets. Laboratory experiments are desperately required to understand the evolution and life cycle ofcosmic dust grains not only to identify cosmic dust components and to deﬁne building materials for larger
bodies such as planets and comets, but also to obtain information on conditions in the corresponding
astrophysical environments. This talk considers recent progress in laboratory approaches on dust anddust/ice experiments that help to understand the formation processes of diﬀerent dust materials, but also
demonstrates the possible signiﬁcant changes in composition and structure as well as erosion of major dust
components.

High-resolution view of the inner circumgalactic medium of NGC891
Ilse De Looze
Wednesday, September 27

ITDepartment of physics and astronomy, Ghent University
The baryonic cycling of the material pushed out of the galactic midplane by stellar and/or supernova feedback
processes, and the fallback of cool circumgalactic gas onto the disk is uniquely observed in edge-on galaxies.
As such, NGC 891 is a perfect target to study the life-cycle of baryonic material. Its virtually perfectly edge-on
inclination (89.7 degrees) and closeness ( 9.6 Mpc), together with the sensitivity and resolution of JWST
imaging instruments lets us probe faint structures in the circumgalactic medium down to 10 pc scales. We
were able to conﬁrm the presence of dust out to 5 kpc (S/N >= 3), forming a loop-like structure, tentatively
suggesting the existence of a galactic fountain. Using unsharp masking techniques and Spitzer/IRAC 8 micron
data, we investigate the connection of these ﬁlament-like structures to the disk, and their association topotential star forming regions, which could be the drivers of expelled interstellar material outside of thegalaxy. We also track the distribution of small clumps, whose sizes range from 10 to 30 pc, suggesting theexistence of small pockets of processed dust grains out in the CGM.

50

Modeling dust formation in supernovae in the JWST era
Arkaprabha Sarangi
Wednesday, September 27

CT

Niels Bohr Institute [Copenhagen]The formation of molecules, molecular clusters, and solid grains of dust, control the chemical budget ofsupernovae (SNe) from their nebular phase to the remnants. Quantifying the mass and composition ofdust in SN ejecta enable us to study the hydrodynamics of the SNe, in terms of the nature of the explosion,geometry of the ejecta, the mass of the ejecta, pre-explosion activities of the massive star, degree of mixing
and clumpiness of the layers induced by the explosion. Based on the type of progenitor, theories predictthe dominance of C-rich (expected in smaller progenitor stars) or O-rich dust components (expected inlarger progenitors). Moreover, the timescales of dust formation for individual species diﬀers based on
the densities of the clumps and the cooling rates deﬁned by elements present in those clumps. In recent
years, we have realized that the interaction of the SN shock with circumstellar environments inﬂuence thephysical and chemical evolution of the SN profusely. In many interaction-dominated SNe, dust is assumed
to form in the post-shock gas (behind the SN blast wave), with a larger survival rate when merging with
the ISM. The molecules are crucial in determining the pathways to form various dust grains, in addition to
being responsible for the rapid cooling of the gas. Possibility of detection of molecules in extragalactic SNe,decades after the explosion, provides the critical evidence for determining the pathways of dust formation.
In addition, tracing the rate of dust production until late times helps us understand the mechanism of
dust growth, which is connected to the compactness of the core and the mantle of these dust grains. The
destruction of these grains by the reverse shock is aﬀected by this outcome. At any given time, the range ofdust temperatures in SNe can vary over a wide range, thereby radiating at all wavelengths from near-IR
to submm wavelengths. Several evidence points towards the likely presence of large masses of cold dust,
however prior to the JWST era we had no tools to test that. Thanks to the ongoing detections of dust
reservoirs in several extragalactic supernovae, using the mid-IR data from the JWST, we now have a much
improved understanding of the role of SNe as dust producers in galaxies. In my talk, I will present the current
state-of-the-art in the ﬁeld of supernova dust, explaining the physics and chemistry of dust formation insuch environments.

51

Massive Dust Reservoirs in Normal Galaxies at Redshift 7
Hiddo Algera
Wednesday, September 27

CT

Hiroshima University
National Astronomical Observatory of Japan (NAOJ)
In recent years, ALMA has detected (sub-)millimeter continuum emission from dozens of galaxies at z > 6.5,
thereby suggesting that the ISM of high-redshift galaxies is rapidly enriched by dust. However, to accurately
constrain the build-up of dust in the distant Universe, following up high-redshift dust reservoirs with multiband ALMA continuum observations is essential. Such observations are needed to break the observational
degeneracy between dust mass and temperature, and hence provide the accurate dust masses required totest theoretical models of dust production in the early Universe. In this talk, I will discuss new multi-band
ALMA observations of normal star-forming galaxies at z 7, and show that some of these have already built up
dust reservoirs of >1e8 Msun only 700 Myr after the Big Bang. Next, I will present new measurements of theinfrared SED of a galaxy at redshift 7.3, which has been carefully constrained through ALMA observations
in six distinct bands. As a result, its dust emissivity index (beta) has been measured with great precision,suggesting a steeper value than what has typically been observed in local and intermediate-redshift galaxies.
I will discuss this intriguing ﬁnding in detail in the context of the dust properties and production mechanismsof high-redshift galaxies.

Thursday, 28th September, 2023

Dust growth in nearby galaxies
Anja Andersen
Thursday, September 28

IT

University of Copenhagen
Studies of nearby galaxies provide unique constraints on fundamental dust processes, as nearby galaxies
span a wide diversity of environmental conditions – such as metallicity, mass, star formation activity, gas
mass fraction, and stellar age – oﬀering a greater dynamic range than is seen in the Milky Way. Nearby
galaxies thereby provide the opportunity to observe dust in extreme conditions. As the evolution of thecosmic dust content and the cycle between metals and dust in the ISM plays a fundamental role in galaxy
evolution, nearby galaxies can also be seen as a necessary intermediate step towards understanding distantgalaxies as they are spatially resolved and typically have better wavelength coverage and a more completeline inventory. I will review what is currently known on the growth of dust in nearby galaxies, with aparticular emphasis on the dust-to-metals ratio and the variation of the gas-to-dust ratio with metallicity
and measurements of depletion as a tracer of dust properties and the destruction-growth cycle.

52

The z<1 drop of cosmic dust abundance
Massimiliano Parente
Thursday, September 28

CT

SISSA
INAF - Osservatorio Astronomico di Trieste
Observations suggest that the amount of galactic dust in the Universe decreased by a factor of 2-3 over the
past 8 billion years. However, explaining this trend usually remains a challenge for existing cosmologicalmodels of galaxy evolution. In this talk I will present a recent work that uses a semi-analytic model (SAM)
to investigate this phenomenon in detail. In particular, the latest version of the L-Galaxies SAM has been
extended with a state-of-the-art dust model and a new disc instability treatment, which triggers bulge andcentral black hole growth. The model predicts a galactic dust drop from z 1 to z=0: it is the ﬁrst time that a
SAM well agrees with the observed trend. I will discuss the role of the diﬀerent dust processes (e.g. grain
growth, destruction), as well as the signiﬁcance of the disc instability treatment for producing this result. I
will also brieﬂy discuss the model predictions concerning extra-galactic dust.

The origin of dust grains within galaxies seen in the ﬁrst billion years of cosmic time
Joris Witstok
Thursday, September 28

CT

Kavli Institute for Cosmology - University of Cambridge
Interstellar dust captures a signiﬁcant fraction of elements heavier than helium in the solid state and is anindispensable component both in theory and observations of galaxy evolution. Even in the early Universe,
dust emission is a primary coolant of the interstellar medium (ISM) and facilitates the gravitational collapse
and fragmentation of gas clouds from which stars form, while altering the emission spectrum of galaxies fromultraviolet (UV) to far-infrared wavelengths through the reprocessing of starlight. However, the astrophysicalorigin of various types of dust grains remains an open question, especially since signiﬁcant dust production
on short timescales has proven challenging for theories of dust formation. In this talk, I will present thedetection of the broad UV absorption feature around 2175 Å in deep JWST/NIRSpec spectra of galaxies up to
the ﬁrst billion years of cosmic time, at a redshift of z 7. This dust attenuation feature has previously only
been observed spectroscopically in older, more evolved galaxies at redshifts of z < 3. Our ﬁndings provide
direct evidence for the early presence of carbonaceous grains giving rise to this feature, often thought
to be polycyclic aromatic hydrocarbons (PAHs) produced on timescales of hundreds of millions of years
by asymptotic giant branch stars. Instead, our results suggest a more rapid production scenario, likely insupernova (SN) ejecta, potentially implying a diﬀerent type of grains as the cause of the absorption. I willfurther show that substantial dust production on such short timescales is required to explain the high dust
yields seen in a sample of 17 galaxies in the early Universe (4 < z < 8) with well-sampled far-infrared spectralenergy distributions (SEDs) compiled from the literature. The observed dust masses, whose degeneracy withdust temperature can only be mitigated with a well-constrained SED, in several sources signiﬁcantly exceed
the prediction of stellar dust build-up even under a highly optimistic dust yield, again pointing towards
additional and/or accelerated dust production channels.

53

Constraining ISM dust properties with stellar polarization and dust emission
Gina Panopoulou
Thursday, September 28

CTChalmers University of Technology
Interstellar dust causes the polarization of background starlight. When combine with polarized dust emission,
this dust-induced-polarization gives a ﬁrm handle on dust properties. Recent results combining stellar
polarimetry and polarized dust emission have nessessitated a re-assessement of existing dust models. I will
discuss what we have learned by these joint studies about the polarizing eﬃciency of dust. I will present a
new database for stellar polarization that can be mined to gain further observational constraints on the
dust properties. I will conclude with future prospects for improving dust models in the general ISM basedon these developments.

Inﬂuence of grain growth on ices spectroscopic proﬁlesEmmanuel Dartois
Thursday, September 28

IT

Institut des Sciences Moléculaires d’Orsay
Interstellar dust grain growth in dense clouds and protoplanetary disks, even moderate, aﬀects the observed
interstellar ice proﬁles as soon as a signiﬁcant fraction of dust grains is in the size range close to the wave
vector at the considered wavelength. The continuum baseline correction made prior to analysing ice proﬁlesinﬂuences the subsequent analysis and hence the estimated ice composition, typically obtained by bandﬁtting using thin ﬁlm ice mixture spectra. We explore the eﬀect of grain growth on the spectroscopic proﬁlesof ice mantle constituents, with the aim of understanding how it can aﬀect interstellar ice mantle spectral
analysis and interpretation. Using the Discrete Dipole Approximation for Scattering and Absorption of Light,
the mass absorption coeﬃcients of several distributions of grains – composed of ellipsoidal silicate andcarbonaceous cores with water and carbon dioxide ice mantles – are calculated. A few models also include
pure carbon monoxide in the ice mantle. We explore the evolution of the size distribution starting in thedense core phase in order to simulate the ﬁrst steps of grain growth up to three microns in size. The resulting
mass absorption coeﬃcients are injected into RADMC-3D radiative transfer models of spherical dense coreand protoplanetary disk templates to retrieve the observable spectral energy distributions. Calculations
are performed using the full scattering capabilities of the radiative transfer code. We then focus on theparticularly relevant calculated proﬁle of the carbon dioxide ice band at 4.27 microns. The carbon dioxide
antisymmetric stretching mode proﬁle is a meaningful indicator of grain growth. The observed proﬁletoward dense cores with the Infrared space observatory and Akari satellites already showed proﬁles possibly
indicative of moderate grain growth. The observations with the JWST present distorted proﬁles that willallow constraints to be placed on the extent of dust growth. The more evolved the dust size distribution, themore the extraction of the ice mantle composition will require both understanding and taking into accountgrain growth.

54

Molecular content in Si + C dust growth processes for laboratory astrophysics
Sandra Wiersma
Thursday, September 28

CT

IRAP, Université de Toulouse III - Paul Sabatier, CNRS, CNES
The outﬂows of C-rich AGB stars produce a rich, dusty chemistry in which silicon carbide (SiC) dust is of major
importance. It is the second-most common form of dust after amorphous carbon (a-C). Polycyclic aromatichydrocarbons (PAHs) are often put forward as an intermediate towards a-C growth, but the formation
mechanisms of the PAHs themselves are not clear. Laboratory simulations with an increased chemicalcomplexity, for instance through the addition of Si, are needed. We study the hydrocarbon chemistry of
diﬀerent forms of carbon in reaction with silicon using two diﬀerent dust reactors. In the Stardust setup [1],Si and C atoms are produced by sputtering of solid targets with Ar+-ions, and aggregate in the presenceof a lateral H2 ﬂow. Reaction temperatures are estimated at 500 – 1000 K. In PIRENEA 2 [2], one or twosolid rods (Si and/or C) are laser vaporized in the presence of a He pulse which can be seeded with H2 or
C2H2. Temperatures are estimated at < 4000 K in the plasma plume. For both setups, dust (analog) deposits
were prepared for ex-situ analysis with the high-resolution laser desorption/ionization molecular analyzer
AROMA [3]. The AROMA analyses of samples from both setups reveal a large variety of hydrocarbons, inparticular of PAHs whose detection is optimized by the used laser scheme. The PAH formula with the highest
intensity in most mass spectra is C16H10+, mimicking meteoritic ﬁndings [4]. Note that C16H10+ has several
isomers. The Stardust experiment shows that Si strongly promotes the formation of PAHs compared toC-only experiments [1]. In PIRENEA 2, the addition of Si promotes the growth of PAHs with odd numbers ofcarbon. We conclude that Si likely plays a signiﬁcant role in circumstellar hydrocarbon chemistry. Future
research will examine the role of iron. Acknowledgements: We thank the European Research Council for
funding support under Synergy Grant ERC-2013-SyG, G.A. 610256 (NANOCOSMOS) and l’Agence Nationale
de la Recherche in France under project ANR GROWNANO (ANR-21-CE29-0001). We also thank Loïc Noguès
for technical support. References: [1] L. Martínez et al. (2020). Nat. Astron., 4(1), 97–105. [2] A. Bonnamy etal., (2018), 22nd Int. Mass Spectrom. Conf., Florence [3] H. Sabbah et al., (2017), Astrophys. J., 843(34), pp.
1–8 [4] H. Sabbah et al. (2022) Astrophys. J. 931(2), 91.

55

From dust to pebbles: revisiting grain growth in protoplanetary disks
Leonardo Testi
Thursday, September 28

CT

Università di Bologna
The initial stages of planet formation involve the growth of dust particles from submillimetre sizes topebbles and planetesimals. Much of the early observational work focused on the characterization of thesubmillimetre emissivity of dust in protoplanetary disks from the mid-90s to the mid-2010s. In the last 5-10
years ALMA has transformed the ﬁeld bringing to light some of the limitations of the initial measurements
and analyses. In this contribution I will discuss our current understanding of grain growth and trapping indisks from submillimetre observations, presenting also the results of recent multi wavelength population
studies, as well as multi-wavelength high angular resolution observations of individual disks. Taken together
these results highlight the higher than previously appreciated importance of optical depth in the analysisof the submillimetre spectra of protoplanetary disks. The combined analysis still indicates the presenceof signiﬁcantly large grains in protoplanetary disks, but highlights the importance of early growth, earlyplanet formation and dust reeneration (through larger bodies collisions). I will show the combined result ofmulti-wavelength spatially resolved ALMA observations of the protoplanetary disk populations in Ophiuchus,
Lupus, Chamaeleon and Upper Scorpius regions, and will put the current results and constraints on dust
properties and evolution in the context of planet formation, also highlighting the major challenges in theﬁeld that will be addressed by future observations at radio and infrared wavelengths.

56

The nearby universe:A laboratory to study the cosmic build-up of interstellar dust in
galaxies
Julia Roman-Duval
Thursday, September 28

ITSpace Telescope Science Institute
A key component of the baryon cycle in galaxies is the cycle of metals between the gas and the dust phasesin the neutral interstellar medium (ISM). The resulting variations in the abundance of interstellar dust
have important implications for how accurately we can trace the chemical enrichment of the universe overcosmic time. Furthermore, variations of the abundance and properties of dust within and between galaxies
profoundly aﬀects their evolution, given the key role that dust plays in the chemistry, radiative transfer, andthermodynamics of galaxies. In this talk, I will present results from two observational eﬀorts to characterize
how the dust abundance varies with metallicity and gas density using nearby galaxies as laboratories. The
ﬁrst method uses emission-based tracers of the interstellar medium (FIR, HI 21 cm, CO rotational emission)
to map their dust and gas content, while the second method uses UV absorption spectroscopy with Hubble
to directly count metals in the gas-phase. Both types of studies demonstrate a signiﬁcant increase of theabundance of dust (and of the fraction of metals locked in dust) with gas density that is very likely due
to dust growth in the ISM (with a density-dependent timescale). Furthermore, we ﬁnd that the fractionof metals locked in dust decreases with decreasing metallicity, by a factor of 30 from the Milky Way to
Sextans A (10% solar metallicity) at log NH = 20 cm-2 (factor 2.3 at log NH = 21 cm-2). This variation of
the dust-to-metal ratio is predicted by chemical evolution models that include dust growth in the ISM,
dust destruction by supernova shocks, and dust dilution by inﬂows of pristine gas. However, a tension still
remains between, on the one hand, dust-to-gas ratio measurements obtained from FIR emission in nearby
galaxies and chemical evolution models, and on the other hand, dust-to-gas ratio estimates from rest-frame
UV spectroscopy in nearby galaxies and high-redshift neutral gas systems.

Rethinking the Nature of Dust in the Diﬀuse ISM
Brandon Hensley
Thursday, September 28

ITDepartment of Physics, Princeton University
Interstellar dust has long been modeled with separate silicate and graphite/amorphous carbon components.
In this talk, I will argue that initially distinct populations of stardust get rapidly homogenized in the ISM into
a composite material ("astrodust"). I will show that the astrodust+PAH model is compatible with current
observational constraints on dust extinction and emission in the diﬀuse ISM, and that it provides a morenatural explanation for the observed polarized emission than do two-component models.

57

Predicting the dust condensation sequence from a bottom-up perspective
David Gobrecht
Thursday, September 28

CT

University of Gothenburg
Classical condensation sequences rely on chemical and thermal equilibrium conditions that are typicallyderived from crystalline bulk material in a top-down manner. However, many astrophysical environmentsthat show active signatures of dust formation are highly dynamical. Therefore, a non-equilibrium (i.e.
kinetic), bottom-up treatment represents a more realistic description of dust grain nucleation and growth.
In this talk I will present and review the latest results on accurate quantum-chemical calculations of (sub)nanometer sized clusters including alumina (Al2O3), titania (TiO2) and vanadia (V2O5), and mixed metaloxides spinel (MgAl2O4), krotite (CaAl2O4) and magnesium-rich silicates (MgSiO3, Mg2SiO4). Based on
the most favourable cluster structures and their thermochemical properties we derive a bottom-up obtained condensation sequence that depends on particle size, temperature and pressure. Moreover, we
examine chemical-kinetic routes towards the formation of the corresponding monomers and dimers todetermine their time-dependent abundances in dynamical physico-chemical outﬂow models. Combining
the abundances with the derived spectral ﬁngerprints of the clusters allows us to compare our synthetic
model spectra with the most recent JWST observations.

58

Using JWST Photometry to Determine What Sets the PAH Distribution in Nearby Galaxies
Jessica Sutter
Thursday, September 28

CT

University of California [San Diego]
JWST provides an exciting new opportunity to study dust in nearby galaxies. The high-resolution of the
MIRI and NIRCam photometry allow us to map the emission of polycyclic aromatic hydrocarbons (PAHs)
in exquisite detail. As the PAHs play an important role in regulating heating and electron density in theinterstellar medium (ISM), the distribution and properties of the PAHs are essential components of acomplete model of energy transport in the ISM. Thus, understanding how ISM phase, galaxy environment,
and properties like galactic radius and metallicity aﬀect the PAHs is a necessary step towards expanding ourunderstanding of how these small dust grains impact their environments. In pursuit of these goals, we havedeveloped a proxy for the PAH-fraction of dust content that we call RPAH based on combinations of the MIRI
bands. RPAH is the ratio of sum of the PAH-tracing F770W and F1130W bands divided by the F2100W band,
which traces larger dust grain emission. To verify the utility of RPAH, we present comparisons between
RPAH and qPAH determined through dust modeling. The strong correlation between these two properties
suggests RPAH is a good photometric indicator of the PAH fraction. Based on these results, we present trends
in RPAH with galactic radius, metallicity, gas content, and galaxy environment from the full set of galaxies
in the Physics and High Angular resolution in Nearby GalaxieS (PHANGS) JWST sample (Cycle 1 Treasury
Program 2107, PI Lee) . This sample contains star-forming galaxies spanning a range of morphological types
with distances less than 20 Mpc. At these distances, JWST is able to resolve individual giant molecular
clouds. Through comparisons to Halpha emission from MUSE, CO emission measured by ALMA, and HI datafrom the VLA, we can determine which ISM phases produce a majority of the PAH emission and how thisvaries between the galaxies in our sample. We can further determine how the PAHs vary outside of HII
regions, where hard radiation destroys these small grains. The observed trends have implications for where
we expect PAHs to play a prominent role in heating the ISM, and where these small dust grains are being
destroyed by hard radiation ﬁelds.

59Dust growth in high-redshift galaxies and its impact on the grain size distribution
Hiroyuki Hirashita
Thursday, September 28

IT

Academia Sinica
Dust can grow by the accretion of gas-phase metals in the interstellar medium. This process is proposed
to be important to account for the dust abundance in high-redshift galaxies. Accretion also aﬀects thegrain size distribution, which inﬂuences the dust extinction properties. Thus, we construct an evolution
model of grain size distribution in a galaxy by considering interstellar processing in addition to stellar dust
production. We ﬁnd that dust growth by accretion has a large impact on the grain size distribution in such a
way that the abundance of small grains increases dramatically. This aﬀects the extinction curve, and opens
a possibility of discriminating the dust sources by observing dust extinction at various wavelengths. We also
consider another dust growth mechanism, coagulation, which determines the maximum grain radius, andsuggest that submillimeter galaxies could potentially be used as laboratories of dust coagulation. We ﬁnallyintroduce some recent numerical eﬀorts for hydrodynamic simulations and radiative transfer calculations,and other extended applications for the CO-to-H2 conversion factor and PAH abundances.

Observational constrains on dust grain alignment: from protostellar cores to PDRs
Valentin Le Gouellec
Thursday, September 28

CT

NASA Ames Research Center
The linear polarization of thermal dust emission provides a powerful tool to probe interstellar and circumstellar magnetic ﬁelds, because aspherical grains tend to align themselves with magnetic ﬁelds lines. However,while the Radiative Alignment Torque (RAT) theory provides a quantitative framework for the understandingof this phenomenon, some aspects of this grain alignment mechanism still needs to be quantitatively tested.
One such aspect is the possibility that the reference direction for the alignment may change from themagnetic ﬁeld ("B-RAT") to the radiation ﬁeld k-vector ("k-RAT") in areas of strong radiation ﬁelds, such as
irradiated outﬂow cavity walls toward protostellar cores, or regions aﬀected by massive star formations
feedback mechanisms. Another aspect is the predictions of the RAT theory concerning the evolution ofdust grains in the ISM, i.e., constraining the alignment of large grains is enabled in dense environment,
and the rotational disruption of grains in irradiated regions. We will present several results obtained withobservational and radiative transfer modeling studies toward protostellar cores and PDRs, using ALMA
and SOFIA dust polarization observations, respectively. While the polarized dust emission seemed to be
explained with some degree of dust growth and grain super-paramagnetism in embedded protostars, thedust polarization observed in PDRs tend to discard the k-RAT mechanism. In both cases, rotational disruption
is predicted to be eﬃcient toward the most irradiated and less dense regions, but further observational
probes shall further constrain this grain disruption mechanism.

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Observational evidence of morphological quenching in dusty elliptical galaxies
Aleksandra Leśniewska
Thursday, September 28

CTAstronomical Observatory Institute, Faculty of Physics, Adam Mickiewicz University
Dark Cosmology Centre
The mechanism by which galaxies stop forming stars and get rid of their interstellar medium (ISM) remains
elusive. I will present analysis and results obtained on a sample of more than two thousand elliptical galaxies
in which dust emission has been detected. This is the largest sample of such galaxies ever analysed. Oneof the main result is the timescale for removal of dust in these galaxies and its dependency on physicalor environmental properties. This timescale does not depend on environment, stellar mass or redshift.
Another interesting result is a departure of dusty elliptical galaxies from the star formation rate vs. dust mass
relation. This is caused by the star-formation rates declining faster than the dust masses and indicates that
there exists an internal mechanism, which aﬀects star formation, but leaves the ISM intact. Morphologicalquenching together with ionisation or outﬂows caused by older stellar populations (supernova type Ia or
planetary nebulae) are consistent with these observations.

Rise and Fall of Anomalous Microwave Emission in Extragalactic Star Forming Regions
Ilsang Yoon
Thursday, September 28

CT

National Radio Astronomy Observatory
Anomalous Microwave Emission (AME) is a potential contributor to the radio spectral energy distribution(SED) in the frequency range that we believe is dominated by free-free emission and thermal dust emission.
Although detection of AME from extragalactic star-forming regions is rare compared to the situation in
our own galaxy, it is important to understand why extragalactic AME is rarely observed and how AME
will impact the radio SED when observing galaxies in radio for a wide range of redshift using future radio
telescopes (ngVLA and SKA). In this talk, I will introduce my recent work based on the investigation of AME
emissivity from a massive star-forming region with a strong radiation ﬁeld and shockwave propagating
into the magnetized ISM. Based on recent studies of grain disruption due to centrifugal force by radiativeand mechanical torque, I will illustrate how AME can be suppressed relative to free-free and thermal dust
emission. I will also discuss how AME ﬂux from extragalactic star-forming regions will change as galaxies areplaced at higher redshifts.

Friday, 29th September, 2023

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Dust destruction in supernova remnantsElisabetta Micelotta
Friday, September 29IT

Nanoform
University of Helsinki
Dust processing and destruction in supernova remnants is a topic of active research. Supernovae are eﬃcientdust factories, as predicted for a long time by theoretical models and recently conﬁrmed by observations.
In particular, they represent the major potential suppliers of dust in the early Universe, due to the rapid
evolution of their stellar progenitors combined with their eﬃciency in condensing refractory elements fromthe gas phase into dust grains. However, not all the supernova-generated dust is able to be expelled from theremnants and reach the interstellar medium. Dust must survive a perilous journey from the cavity where it isformed and initially resides. The pressure of the circumstellar material shocked by the expanding supernova
blast wave generates a high velocity reverse shock which propagates across the remnant processing the
freshly formed dust. The result of such processing depends on the properties of both dust grains and theenvironment where they reside, ranging from erosion to complete destruction. In this review, I will present
the state of the art about dust destruction in supernova remnants, summarizing theoretical results andobservational ﬁndings.

The Disappearing Act: Exploring the PAH Deﬁcit at Low Metallicities
Elizabeth Tarantino
Friday, September 29

CTSpace Telescope Science InstituteIn typical star-forming galaxies, the mid-infrared spectrum is dominated by emission from Polycyclic Aromatic
Hydrocarbons (PAHs), the smallest dust grains found in the interstellar medium. However, in regions with low
metallicities, the fraction of PAHs in the interstellar medium undergoes a signiﬁcant decline. The underlying
cause for this deﬁcit remains unknown with several possible suggested explanations. One possibility isthat the higher ultraviolet radiation ﬁelds common in low metallicity galaxies may more readily destroy the
PAHs. Alternatively, PAH growth in the ISM may be inhibited in metal poor systems because of the lack ofavailable carbon for formation and lower gas densities. PAHs can be used as a tracer of star formation rate
and molecular gas, although their sensitivity to metallicity makes it extremely important to understandthe eﬀect of environment on their abundance. In this talk, I will provide an overview of previous attempts
aimed at detecting PAHs in low metallicity environments and explore the proposed explanations for the
PAH deﬁcit. I will also present on-going analysis of new JWST imaging of the 3.3, 7.7, and 11.3 PAH features in
two nearby, low metallicity galaxies Sextans A (7% solar metallicity) and IC 1613 (10% solar in O; 20% solar in
Fe). These deep JWST observations of Sextans A and IC 1613 will provide valuable insights into the variationsof PAH abundance in diﬀerent environments, allowing us to better constrain the mechanisms responsible
for their formation, destruction, and excitation.

62

Empirical constraints on dust destruction in supernova remnants
Felix Priestley
Friday, September 29

CT

Cardiﬀ University
One of the key processes removing dust from the interstellar medium is the destruction of grains inshockwaves driven by supernovae (SNe). Existing theoretical models predict that each SN can ’clear’ dust
from roughly 1000 Msun of the interstellar medium (ISM), thus destroying 10 Msun of dust for a Milky
Way gas-to-dust ratio of 100. However, these models typically assume an ISM with a uniform density of 1
cm-3, rather than a realistic multiphase structure, and rely on poorly-constrained dust physics such as grain
shattering. I test the accuracy of these simulations by determining the distribution of the dust mass in asample of Galactic supernova remnants between the cold (<1000 K) and hot ( 106 K) phases of swept-up
ISM, and between large and small grain sizes. Contrary to model predictions, for all objects the vast majority(>90%) of the swept-up dust mass is located in the cold phase, and the grain size distribution in the hotphase is inconsistent with that expected from shattering. If shattering is ineﬃcient, and most of the dust is
not exposed to the high-temperature shocked gas, dust destruction rates are likely to be far lower thancommonly-adopted theoretical values would suggest. I argue that this reduction in destruction eﬃciency isnecessary in order to explain the depletion patterns of elements in the diﬀuse ISM, which are diﬃcult toreconcile with rapid destruction of dust by SNe.

63

Interstellar carbonaceous dust erosion induced by X-rays irradiation of water ice instar-forming Regions
Ko-Ju Chuang
Friday, September 29

CT

Leiden Observatory
Interstellar dust grains play an essential role in enriching molecular complexity by providing catalyticalsurfaces to allow atomic or simple species to accrete, meet, and react. Astronomical observations using
ground and spaceborne instruments (Spitzer, Herschel, and more recently, JWST) have revealed the great
details of the interstellar ice composition, mainly constituting H2O, CO, and CO2. The physicochemicalinteractions between the above ice and dust surfaces and icy dust morphology remain unclear due to limited
experimental work. This study aims to provide a better understanding of the possible ice-dust reactions
using selectively isotope-labeled oxygen/carbon species. Ultrahigh vacuum experiments were performed to
study the X-ray irradiation of interstellar ice analog on sub-micrometer thick C dust at ∼13 K, mimicking theproto-planetary midplane conditions. H2O and O2 ice were deposited on the pre-synthesized amorphous
C dust and exposed to soft X-ray photons (250–1250 eV). Kinetic analysis of the reaction products was
performed using Fourier-transform infrared spectroscopy. Field emission scanning electron microscopy wasused to monitor the morphological changes of (non-)eroded carbon samples. Experimental results show that
the X-ray processing of the ice-dust interface leads to C dust erosion accompanied by the formation of CO2
and CO. The erosion process is conﬁrmed due to oxygen addition to grain surfaces forming carbonyl groups
as an intermediate product. The yields of CO and CO2 were found to be dependent on the thickness of the
carbon layer, implying the studied dust erosion might aﬀect the chemical composition in protoplanetarydisks where X-ray is the dominant energetic source and icy dust starts coagulation.

Radiative Torque Disruption and Implications
Le Ngoc Tram
Friday, September 29

IT

Max Planck Institute for Radio Astronomy
The interaction of the radiation ﬁeld can cause large dust grains to spin suprathermal. This suprathermal
rotation could induce rotational disruption of large grains into small fragments, which determines the upper
cutoﬀ of the grain size distribution (GSD) and causes the variation of GSD with the radiation ﬁeld. This new
mechanism is named after Radiative Torque Disruption (RAT-D). The modiﬁed GSD by RAT-D, in turn, aﬀects
dust optical-UV extinction, thermal emission from infrared to radio wavelengths, and polarization. This talkwill review the RAT-D mechanism and its implications, primarily focusing on dust polarization studies.

64

From total destruction to complete survival: Dust in supernova remnants at diﬀerent
evolutionary stages
Florian Kirchschlager
Friday, September 29CT

Ghent University
The expanding ejecta of supernova remnants (SNR) forms dust in over-dense clumps of gas. Before the dust
can be expelled into the interstellar medium and contribute to the interstellar dust budget, it has to survive
the reverse shock that is generated through the interaction of the preceding supernova blast wave withthe surrounding medium. The conditions at which the reverse shock hits the clumps change with remnant
age and deﬁne the dust survival rate. To study the destruction in the SNR Cassiopeia A, we conductedmagnetohydrodynamical simulations of the evolution of a supernova blast wave and of the reverse shock.
In a second step we used these evolving conditions to model clumps that are disrupted by the reverse shockat diﬀerent remnant ages. Finally, we computed the amount of dust that is destroyed by the impact of thereverse shock. We ﬁnd that most of the dust in the SNR is hit by the reverse shock within the ﬁrst 200 yr
after the SN explosion. While the dust destruction at this early phase is almost complete, we expect greater
dust survival rates at later times and almost total survival at ages beyond 1000 yr.

65

Posters abstracts

1 - ALMA observations of Titanium and Aluminium bearing species in Mira
Maryam Saberi
University of OsloAsymptotic giant branch (AGB) stars stand out as prominent contributors to the production of dust within
our Galaxy. However, the intricate process of inorganic dust grain condensation in the outﬂows of AGB stars
remains uncertain. Theoretical investigations, rooted in chemical and thermal equilibrium, have pinpointed
aluminium oxides, titanium oxides, and silicon oxides as the primary contenders for serving as the nuclei
around which dust particles coalesce in M-type AGB stars. Nevertheless, the mechanisms responsible forthe remarkably eﬃcient coagulation of molecules into dust grains remain poorly understood. In this study,
our objective is to probe the formation of dust surrounding the nearby M-type AGB star, Mira, using ﬁnely
resolved observations from the Atacama Large Millimeter/submillimeter Array (ALMA) across Bands 6, 7,
and 8. Our analysis has successfully identiﬁed multiple spectral lines, including 46TiO, 48TiO, 49TiO, 50TiO,
46TiO2, 47TiO2, 48TiO2, 49TiO2, 50TiO2, AlO, AlCl, AlF, SO2, SO, SO2, SiO, and SiS. We have employed therotational diagram method to meticulously estimate the column density and abundance of the majority ofthese detected species through multiple observations. We aim to provide a more precise characterizationof the aluminum and titanium budgets within the inner outﬂow region of Mira, with the ultimate goal of
shedding light on the intricate processes governing dust formation in Mira’s inner outﬂow.

2 - Alternative Dust Grain Formation: Pathways of Formation from Alane and Ammonia
C. Zachary Palmer
The University of Mississippi
Aluminum’s highly refractory nature grants it easier aggregation into bulk solid-phase grains suggesting alarge contribution to the dust grain formation present in the interstellar and circumstellar medium (ISM
and CSM). For years, alumina and other [Al, O] complexes have dominated the ﬁeld of astrochemical andastrophysical research into the origins of interstellar and circumstellar dust grains. However, previous studies
indicate that aluminum may also assist in the formation of these dust grains in the form of aluminum nitride(AlN) clusters opening an avenue of currently underexplored research. The present study provides a novel
reaction pathway and rovibrational spectroscopic data, where applicable, for [Al, N] clusters that may bepresent in the interstellar medium. This is done through the use of quartic force ﬁelds with assistance from
DFT methods to provide the spectroscopic data included herein. Such data will assist current, available
technologies, like the Atacama Large Millimeter/submillimeter Array or the James Webb Space Telescope,to assist in further understanding dust grain chemistry in the ISM and CSM.

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3 - Collision Induced Dissociation of Water Pyrene Molecular Clusters
Arya M Nair
IRAP, Université de Toulouse
In photodissociation regions (PDRs) associated with star formation, matter composed of gas and tiny
dust particles is in strong interaction with the ultraviolet radiation from young stars. From the analysis
of observations of infrared space missions such as Spitzer, it is proposed that isolated polycyclic aromatichydrocarbons (PAHs) are produced from the destruction of carbonaceous very small grains (C-VSGs) at edgeof PDRs [1]. Clusters of PAHs have been proposed as models for these C-VSGs [2]. They come from theinner part of interstellar clouds where models predicts transition from gaseous to icy water [3]. They are
therefore expected to interact with molecules such as water, a process that can be also of special interestin the models of planet-forming discs [4]. This motivates our experimental study on water-PAH molecularclusters. Mixed pyrene (C16H10, Py) - water cationic clusters are produced in a gas aggregation sourcecooled at liquid nitrogen temperature [5] prior to thermalization at 25K. The observed clusters are either inprotonated (predominant), native or dehydrogenated forms. Collision induced dissociation (CID) is used inorder to study the energetics of the produced species and get insights into their structure. The species ofinterest are mass selected and undergo collisions with inert gases at varying kinetic energy of the ions. The
products are analysed by time-of-ﬁght mass spectrometry and the absolute fragmentation cross sections
are recorded. CID experiments were performed on (Py)m(H2O)nH+ (m= 1 to 3, n= 1 to 10) and (Py)1(D2O)nD+(n= 1 to 9) at 7.5 eV centre-of-mass collision energy. Both water loss and pyrene loss channels are observed.
For (Py)1(D2O)nD+, we could also observe contribution from H-D exchange. Complementary Threshold
CID (TCID) measurements were performed for complexes made of one pyrene molecule (protonated anddehydrogenated) and 1 to 5 water molecules. The variation of the dissociation threshold with the species
gives us extra information about the structure and energetics of these species. Finally, calculations were
performed to obtain structural and energetic data and support the analysis of the experimental results interms of proton localization and dissociation energies. The results obtained so far will be presented anddiscussed. [1] P. Pilleri et al, A.&A. 542, A69(2012). [2] M. Rapacioli et al, A.&A. 429, 193–204(2005). [3]
D. Hollenbach et al, Astrophys. J. 690, 1497(2009). [4] B. Ercolano et al, MNRAS 512, 430-438(2022). [5] I.
Braud et al, Rev. Sci. Instrum. 88, 043102(2017).

67

4 - DEATHSTAR – Accurate mass-loss-rate estimates for AGB stars
Miora Andriantsaralaza
Uppsala Universitet
Mass loss by a stellar wind is a decisive process for late stellar evolution. The mass loss during the Asymptotic
Giant Branch (AGB) is thought to be dust-driven, as radiation pressure on dust grains pushes the grains andthe surrounding gas out of the stellar gravitational ﬁeld due to gas and dust momentum exchange. A vast
amount of elements formed on the AGB are thus ejected into the interstellar medium via their massive
dusty outﬂows. Accurate characterization of this mass loss phenomenon is, therefore, key to advancing ourcomprehension of stellar evolution and the chemical enrichment of the Galaxy. The DEATHSTAR project
aims to improve the accuracy of measurements of stellar wind parameters of AGB stars by using enhanced
distance estimates and new interferometric observations to constrain radiative transfer models of dust
and gas emissions. In this poster, I will present the current results from the modelling of the spectralenergy distributions of a sample of 27 southern nearby carbon stars in the DEATHSTAR sample. The obtained
radiation ﬁeld and dust properties will then be used as inputs for CO line emission radiative transfer modellingto determine their mass loss rates.

5 - Disentangling galaxy and dust evolution mechanisms through chemical abundances
Stefan van der Giessen
Ghent University
Universidad de Granada
It is a diﬃcult task to constrain the origin of the amount of stars, gas, and dust within a galaxy, as several
mechanisms link their evolution. The total gas mass surface density or the molecular gas mass surface density
regulates the star-formation rate through the Schmidt-Kennicutt law. The star-formation rate determines
the dust-formation rate from asymptotic giant branch stars and supernovae, present in regions of relatively
high molecular gas mass surface density, where dust also accretes gas-phase metals on dust grains, theso-called grain growth. Star-formation rate also drives the supernovae rate. Supernovae create energetic
shocks that destroy dust grains and can eﬃciently push the gas outside the galaxy through gas outﬂows.
As all these mechanisms act at diﬀerent time scales, the amount of dust in a galaxy is directly linked tothe star formation history and how much galaxy material is expelled in the circumgalactic medium by thepowerful galactic outﬂows. We can potentially disentangle the evolution eﬀects by adding information on
the chemical abundances of several elements. Oxygen primarily forms in high-mass stars and gets released
by supernovae, whereas nitrogen forms in low and intermediate-mass stars and requires oxygen to enhance
the formation. The stellar lifetimes of the oxygen and nitrogen sources diﬀer, making the relative ratio agood tracer for the potential shape of the star-formation history. The goal of the talk is to showcase spatiallyresolved maps of the stellar mass, gas mass, and dust mass surface density for local spiral galaxies NGC628,
M101, M33, and NGC300 to motivate the use of a chemical and dust evolution code for disentangling thediﬀerent evolution mechanisms within these galaxies. This poster will highlight radial proﬁles corresponding
to these maps and how diﬀerences in the dust-to-stellar mass ratio and the dust-to-metal ratio can be
explained by showing how these ratios vary with oxygen abundance and the nitrogen-to-oxygen abundance
ratio.

68

6 - Dust Coagulation in Oxygen-rich Circumstellar Outﬂows
Joseph Nuth
NASA Goddard Space Flight Center
Ineﬃcient growth of SiO molecules on (SiO)x dust grains prolongs the period of maximum dust nucleationin circumstellar outﬂows resulting in a several order-of-magnitude increase in dust density near the star.
This increase in dust density powers dust coagulation and results in the formation of fractal aggregates thatare extremely eﬃcient per unit mass in coupling to both the stellar radiation ﬁeld and the ambient gas.
Kimura et al. (2022, ApJL, 934, L10) showed that for SiO molecules colliding with (SiO)x clusters, the growtheﬃciency is approximately 0.01; e.g., only 1 in 100 molecules that hit a growing cluster are incorporated
into the grain. During grain formation SiO is depleted both by the formation of stable dust nuclei andby the growth of these grains. Ineﬃcient dust growth slows the depletion of SiO molecules into growing
grains and results in the production of many orders of magnitude more stable dust nuclei that also growmore slowly. A decrease in the average ﬁnal grain radius from 0.5 microns to about 5 nm for the same
fractional SiO depletion, increases the grain number density by a factor of a million. Since the coagulation
rate increases with the square of the primary grain number density, the coagulation rate of these smaller
grains is a factor of a trillion higher than for larger dust grains. This has some interesting consequences. First,
circumstellar outﬂows around oxygen-rich stars will produce copious quantities of fractal dust grains. Thesegrains have a very high surface to volume (or mass) ratio and will be very eﬃcient catalysts for chemistry incircumstellar shells. Second, while individual nanometer-scale dust grains are much less eﬃcient (per grain)
in absorbing or scattering photospheric emission from an AGB star, the much greater number density offractal aggregates of these smaller grains more than compensates for their ineﬃciency such that, per unit
condensed silicate mass, fractal dust particles are more eﬃcient “sails” powering AGB outﬂows. As fractal
aggregates become larger, they are more eﬃcient radiators, potentially requiring modiﬁcations to standard
models of the spectral energy distributions of AGB stars.

7 - Dust content in a z∼2 quiescent galaxy
Minju Lee
DAWN/DTU space
This talk presents our recent study of a quiescent galaxy at z∼2 based on deep ALMA Band 4 observations.
We discovered a dust-rich, massive (Mstar ∼ 1e11 Msun) quiescent galaxy at z∼2 that exhibits a high dustto-stellar mass ratio of 0.3%. This is one of the highest dust content measured in quiescent galaxies at highredshift. Based on the spectral energy distribution modeling, the talk will demonstrate how it compareswith the latest measurements in the local and distant universe and discuss the potential origin(s) of theobserved dust in the galaxy, and challenges given the current dust measurements.

69

Dust depletion of metals from from the Milky Way to z∼6
Christina Konstantopoulou
University of Geneva
The cycle of metals between dust and gas plays a fundamental role in the chemical enrichment of the ISM.
Metals are missing from the observable ISM gas phase because they are instead incorporated into dust
grains, an eﬀect we call dust depletion. This eﬀect alters the observed chemical abundances, which can beinferred through absorption-line spectroscopy. Characterizing the dust depletion of metals both in the local
and distant Universe is important to investigate the evolution and origin of metals and dust through cosmic
time. The fraction of metals in dust can be described by the dust-to-metal ratio (DTM) and the dust content
by the dust-to-gas ratio (DTG). These properties can give us clues about the production and destruction
mechanisms of dust and how it evolves with metallicity and over cosmic time. I will present my recent
results on characterizing the dust depletion of several metals using relative abundances in diﬀerent galactic
environments, including the Milky Way, the Magellanic Clouds and damped Lyman-alpha absorbers (DLAs)
towards quasars (QSOs) and towards gamma-ray bursts (GRBs). Our inferred dust depletion measurements
are then used to estimate the DTM, DTG and the dust composition in the ISM in these diﬀerent galactic
environments. These results have implications on the origin of cosmic dust and the dominant processes ofdust production.

70

9 - Dust grain size evolution in local galaxies as a key to understand galaxy evolution
Monica Relano
Ghent University
The physical properties of the dust grains are directly linked to those of the ISM where it is located. Dustis created in LIMS (low-intermediate-mass stars) and SNe (supernovae) but it is also aﬀected by othermechanisms. Dust grains can be destroyed or suﬀer erosion via sputtering in SN shocks, grain-grain collisions
can either result in grain coagulation, producing a larger fraction of big grains, or shattering that acts asa source of small grains. Dust grains can also grow by accreting metals from the gas phase onto theirsurfaces, and thus increasing the total dust mass of the system. Due to all these processes, the dust
grain size distribution in a galaxy evolves with time and the relative abundance of the diﬀerent dust
grain types gives very useful information to study the dust evolution, which in turn is directly linked tothe evolution of galaxies. In the recent years an impressive amount of work regarding dust evolution
has been done by linking the physics of dust to models of chemical evolution of galaxies (De Vis+21,De
Looze+20,Galliano+21). A step forward is to incorporate how the diﬀerent dust grains are modiﬁed along thedust life in the ISM (e.g.Hirashita 15). Hydrodynamical simulations of individual galaxies and cosmologicalvolumes (Granato+21,Aoyama+20), and also semi-analytical models (Triani+20,Vijayan+19,Popping+17) haveincluded the evolution of the diﬀerent dust grains and predict how the small-to-large grain ratio varies
along the evolutionary time. In this talk we present a systematic analysis of the observed spectral energy
distribution of a large sample of galaxies in the local Universe to derive the relative mass fraction between
small and large dust grains. Simulations reproduce relatively well the observations except for the high-stellar
mass regime where dust masses tend to be overestimated. We ﬁnd that 45% of the galaxies in our sample
exhibit a high small-to-large grain ratio. For these galaxies having also high-molecular gas mass fractions
and metallicities, coagulation is not an important mechanism aﬀecting the dust evolution. We provide an
explanation for these galaxies based on metal diﬀusion. We also present a comparison of the small-to-large
grain ratio derived at spatially resolved scales for a small sample of nearby galaxies with simulations ofindividual galaxies including grain size evolution. With these comparisons, we reinforce the use of thesmall-to-large grain mass ratio to study the relative importance of the diﬀerent mechanisms in the dust life
cycle and galaxy evolution.

71

10 - Dust modelling in L-Galaxies semi-analytical model of galaxy formation
Aswin P Vijayan
Cosmic Dawn Center, DTU Space
Hydrodynamical simulations of galaxies provide a way to explore the spatial distribution of star, gas (ordust) within a galaxy. However, they are expensive and time consuming to run and thus exploration ofphysical or observed parameter spaces is diﬃcult. On the other hand semi-analytical models usually run on
top of dark matter only simulations and can explore parameter spaces quickly and cheaply. In this talk, I
will introduce the L-Galaxies semi-analytical model and detail our implement model for dust production
and destruction. The model includes dust production from stars and grain growth in molecular clouds,
and dust destruction from supernovae shocks. Novel features in this work compared to similar eﬀorts
are more accurate consideration of the impact of molecular cloud chemistry on grain growth in dense
molecular clouds, and incorporating information on dust depletion fractions. The former results in thediverse distribution of the dust-to-metal ratio seen in the high-redshift Universe in the model and thelatter to the non-saturation of metals onto dust. The model also predicts grain growth to be the signiﬁcant
dust production mechanism for redshift less than 8. We see that the dust-to-metal ratio in galaxies can beapproximated by a ﬁtting function that depends on the stellar ages and metallicities. I will conclude withhow the results from the model have been successfully used to translate galaxies from hydrodynamical
simulations of the early Universe into the observer space. If time permits I will also detail a work in progresson the exploration of observed parameter space using the latest L-Galaxies model. In this model galaxies
are resolved using concentric rings and enabling spatial studies in semi-analytical models.

72

11 - Dust Properties and Extinction Curves in the Magellanic Clouds, M31, and M33
Petia Yanchulova Merica-JonesSpace Telescope Science InstituteWe present results for dust grain properties in nearby galaxies using two complementary methods. First
we use spatially-resolved HST multiband photometric observations of millions of stars from two large
photometric surveys in the Magellanic Clouds to understand how the interstellar medium (ISM) impacts
dust properties. Our analysis relies on an open-source Bayesian tool which models the photometric spectralenergy distribution of individual stars to derive their dust extinction (A(V), R(V), and fA) and stellar properties(Teﬀ, mass, surface gravity, luminosity, and metallicity) in addition to ﬁtting the distance to each source.
With these results we generate high-resolution 3D maps in key regions of each galaxy and compare thesemaps to the distribution of ISM tracers (the HI column density, CO, the dust mass from IR emission, and thePAH fraction). Our photometry-based approach has the potential to answer questions about the nature ofdust grain features (i.e., the origin of the 2175A bump) and to independently calibrate dust grain models.
Additionally, we study the wavelength dependence of dust extinction and the properties of dust grains indiverse interstellar environments in M31 and M33. We use low-resolution HST UV spectra of a sample ofreddened OB stars obtained by the Space Telescope Imaging Spectrograph together with near-IR to near-UV
HST multiband photometric data to construct the extinction curves for about ﬁfteen sightlines. In addition
to modeling stellar parameters (Teﬀ, log(g), and metallicity), we constrain A(V), R(V) and the Fitzpatrick and
Massa (1990) parameters describing the shape of the extinction curve. We also make a direct measurementof N(HI) using Lyman-alpha absorption lines yielding the dust-to-gas ratio. These are the ﬁrst measurementsof the UV extinction curve in M33 which illuminate dust extinction properties in an environment probing aunique set of physical and chemical evolution properties among Local Group disk galaxies.

73

12 - Dust surface chemistry in the AB Aur protoplanetary disk: observations and models
Pablo Riviere
Observatorio Astronómico Nacional
Chemical reactions in the surface of dust grains are a key element of astrochemical networks. At the highextinction levels of cores in molecular clouds, where temperatures are low, most of the chemical reactions
happen on the surface of grains. Furthermore, organic molecules with six or more atoms, the so-called
Complex Organic Molecules, are formed in the surface of dust grains, via the diﬀusion and reaction ofradicals produced by the photodissociation of stable molecules. Thus, understanding surface chemistry
reactions is key for the study of star and planet formation, as well as for the emergence of life. Planets areformed in protoplanetary disks surrounding young stars. These disks are made of dust and gas, and a mixtureof gas-gas reactions and surface chemistry reactions shapes their chemical evolution, depending on theheight above the mid-plane. In the mid-plane, where planet formation takes place, the physical conditions
are similar to those of dark cores in molecular clouds, and thus surface reactions play a major role. The dust
grains and gas species present in these disks are inherited from the natal cloud, but they are also subject
to an uncertain level of reprocessing. Understanding to what extent the composition of the ice surfaceof dust grains is inherited is a key element for the study of protoplanetary disks. AB Aur is a well-known
A0 star in Taurus-Auriga that host a transitional disk where signs of ongoing planet formation have been
detected. Such signs include a dust trap, a large dust cavity, and twisted isophotes in the ﬁrst-moment
maps of molecular species. We are conducting a detailed study of AB Aur’s protoplanetary disk by means of
single-dish and interferometric radio observations, combined with ancillary and archival data at diﬀerent
wavelengths, as well as with radiative transfer, magneto-hydrodynamical, and astrochemical models. We will
present the results of our studies of continuum emission used to characterize the dust physical properties
and composition in AB Aur, and discuss them in the context of astrochemical networks and surface chemistry
reactions, linking the spatial distribution of chemical species with that of the diﬀerent grain populations.

74

13 - Dusty feedback from massive stars
Elvire De Beck
Chalmers University of Technology
Massive stars eﬃciently lose mass at all stages of their evolution, including the red supergiant (RSG) phase.
Since RSGs are progenitors to type II-P supernovae, how and how much mass is lost signiﬁcantly inﬂuences
the supernova explosion, its light curve, the remnant, and the resultant elemental and dusty yields. The
mass-loss process during the RSG phase is, however, still poorly constrained.
We present recent observational results on NML Cyg, a nearby RSG. High-angular resolution observations
at submillimetre wavelengths using the NOEMA interferometer reveal a high degree of complexity in its
circumstellar environment. In the measured continuum emission, the star is completely outshone by twobodies of dust, which likely are conglomerations of multiple smaller clumps within a distance of roughly
1000 AU from the star. We derive temperatures of 250K and 450K and a total dust mass in these clumps of
0.002 solar masses. The observations also show a much larger molecular envelope than previously assumed
was possible considering the nearby Cyg OB2 association. In addition, the measured molecular emission,from e.g. CO, SO, SO2, and H2S, shows clumps, arcs and shells tracing multiple outﬂow components linked
to highly episodic and anisotropic mass loss.

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14 - Experimental diﬀusion of water through porous amorphous carbon dust analogues
Romain Basalgète
Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University
Jena, Institute of Solid State Physics, Jena
Interstellar dust plays a crucial role in the chemistry of the interstellar medium by providing catalytic surfaces
for the formation of molecules. The surface reactions involved are of primary importance since they have
explained a variety of gas phase abundances in the interstellar medium. These reactions depend primarily
on how the atoms and molecules diﬀuse on the surface and/or through the dust grains. To date, laboratory
experiments have focused on the diﬀusion of volatiles (CO, NH3, CO2, ...) in water ice (e.g. [1]) and very
little is known on the inﬂuence of the dust grains on such processes. Gas transport through porous media
analogous to interstellar dust is also an important topic in cometary science [2]. Interstellar dust analogues
synthesized in the laboratory [3] oﬀer a unique opportunity to better understand the diﬀusion processes indust grains. Here we propose to study such processes for water, which is a major component of interstellar
and cometary ices. Thin layers of water ice were deposited on a cold substrate and covered by carbon
or silicate dust grains produced by pulsed laser ablation of a solid target in a quenching gas atmosphere.
The diﬀusion of water through the dust layers was activated by heating up the substrate. Isothermal
modiﬁcations of the infrared bands of the water over time enabled us to quantify the diﬀusion process andto measure physical parameters of primary importance for astrochemical models, such as the diﬀusivity. In
this context, I will present the main ﬁndings of the studies and I will discuss their astrophysical implications.
[1] Mispelaer et al., Diﬀusion measurements of CO, HNCO, H2CO, and NH3 in amorphous water ice, A&A,
555, A13 (2013) [2] Skorov et al., Activity of comets: Gas transport in the near-surface porous layers of acometary nucleus, Icarus, 212, 867-876 (2011) [3] Jäger et al., Spectral properties of gas-phase condensed
fullerene-like carbon nanoparticles from far-ultraviolet to infrared wavelengths, The Astrophysical Journal,
689:249-259 (2008)15 - Generating candidates in global optimization algorithms using complementaryenergy landscapes
Andreas Møller Slavensky
Center for Interstellar Catalysis, Aarhus University
Global optimization (GO) algorithms, which attempt to obtain the global minimum energy (GM) structure of agiven stoichiometry, can be used to ﬁnd low-energy clusters. Global optimization of atomistic structure relieson the generation of new candidate structures in order to drive the exploration of the potential energy surface(PES) in search for the GM structure. In this work, we discuss a type of structure generation, which locally
optimizes structures in complementary energy (CE) landscapes. These landscapes are formulated temporarily
during the searches as simple machine learning potentials (MLPs) using local atomistic environments. The
CE landscapes are deliberately incomplete MLPs in order to make them smooth, having only few local
minima. This means that local optimization in the CE landscapes may facilitate identiﬁcation of new funnels
in the true PES. We test their inﬂuence on global optimization of an olivine (Mg2SiO4)4 cluster for which wereport a new highly symmetric GM structure.

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16 - High Resolution Spectra of the Galactic Binary Pulsar 4U 1907+09
Jun Yang
Massachusetts Institute of Technology
The accreting pulsar 4U1907-09 is one of 35 high-mass X-ray binaries with known high magnetic ﬁeld
strengths. A detected cyclotron resonance scattering feature at 19 keV leads to a ﬁeld strength of 2E12
G. The system consists of a slowly-rotating ( 440 s) X-ray pulsar accreting from the stellar wind of an O8/9
supergiant. The X-ray pulsar is in a close ( 8.37 d) elliptical orbit (e ∼ 0.28) around its donor. We conducted
an analysis of four High Energy Transmission Grating observations with the Chandra X-ray Observatory for a
total of 140 ks and one NuSTAR observations for 78 ks, at diﬀerent orbital phases, to probe the variationof the absorbing column around the orbit. We measure line ﬂuorescence at Fe K and possibly Si K andother lower Z elements to study dense clumps in the wind of the pulsar’s companion star. The details of the
NuSTAR observation are used to determine the higher energy continuum beyond 10 keV.

17 - High-resolution view of the inner circumgalactic medium of NGC891
Ilse De Looze
Department of physics and astronomy, Ghent University
The baryonic cycling of the material pushed out of the galactic midplane by stellar and/or supernova
feedback processes, and the fallback of cool circumgalactic gas onto the disk is uniquely observed in edge-on
galaxies. As such, NGC 891 is a perfect target to study the life-cycle of baryonic material. Its virtually perfectlyedge-on inclination (89.7 degrees) and closeness ( 9.6 Mpc), together with the sensitivity and resolutionof JWST imaging instruments lets us probe faint structures in the circumgalactic medium down to ∼10
pc scales. We were able to conﬁrm the presence of dust out to ∼5 kpc (S/N >= 3), forming a loop-likestructure, tentatively suggesting the existence of a galactic fountain. Using unsharp masking techniquesand Spitzer/IRAC 8 micron data, we investigate the connection of these ﬁlament-like structures to the disk,
and their association to potential star forming regions, which could be the drivers of expelled interstellar
material outside of the galaxy. We also track the distribution of small clumps, whose sizes range from 10 to
30 pc, suggesting the existence of small pockets of processed dust grains out in the CGM.

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18 - Interstellar Dust Extinction from the Far-Ultraviolet to the Mid-Infrared
Karl Gordon
Space Telescope Science InstituteGhent University
Dust extinction measurements provide important constraints on the size, composition, shape, and abundance of dust grains and an empirical model to account of the eﬀects of extinction on astrophysical objects.
For decades our understanding of dust grains was strongly biased by measurements in our Galaxy andthe ultraviolet (UV). The UV bias is due to the extensive spectroscopic observations taken with the IUE
satellite revealing the details of the 2175 A bump, far-UV rise, and underlying extinction continuum. I will
discuss the results of a dedicated eﬀort to expand our spectroscopic measurements of dust extinction
to the far-UV, optical, near-infrared, and mid-infrared wavelength regimes. This work has revealed new
optical extinction features, enabled the ﬁrst combined combined study of UV and MIR extinction features,shown the possible presence of ice in the diﬀuse interstellar medium, and revealed an intriguing correlation
between UV extinction and molecular hydrogen. Building on these works, a new R(V) dependent extinction
relationship at spectroscopic resolution from 912 A to 32 microns has been determined. Finally, preliminary
JWST extinction curves in the near- and mid-infrared will be shown.

19 - Magnetic ﬁeld revealed by polarized dust emission in G28.34
Jihye Hwang
Korea Astronomy and Space Science Institute
Magnetic ﬁeld plays an important role to support star-forming regions against gravitational collapse. However,in dense cores or clumps, gravity exceeds magnetic support and stars are formed. The correlation between
magnetic ﬁeld and core fragmentation is not fully understood. Magnetic ﬁeld orientations, and relative
energies of turbulence, gravity and magnetic ﬁeld can aﬀect the core fragmentation. We estimate magnetic
ﬁeld orientations and those energies in a massive cloud, G28.34 using JCMT and ALMA polarization data
to show magnetic properties in a cloud and core scales. Magnetic ﬁeld orientations in the cloud and corescales are roughly perpendicular to each other, which can result from the eﬀect of outﬂow in the core scale.
Magnetic ﬁeld strength in the cloud scale is 1.3 mG which is comparable to that in the core scale of 1.6 mG.
The relative importance between gravity and magnetic ﬁeld can be expressed using the mass-to-ﬂux ratio
which is 0.3 in G28.34. It means the magnetic ﬁeld is strong enough to support G28.34 against gravitational
collapse. Magnetic ﬁeld energy is one order of magnitude larger than gravitational and turbulent energies
in the cloud scale of G28.34. From these results, in the cloud scale, the magnetic ﬁeld is more dominantcompared to turbulence and gravity. However, the magnetic ﬁeld in the core scale is aﬀected by outﬂows
which can cause the core fragmentation in G28.34.

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20 - Mapping the interstellar dust and ice with JWST
Burcu Günay (Karl Gordon)
Space Telescope Science InstituteJohns Hopkins University
In the interstellar medium (ISM), the refractory compounds form interstellar dust and volatile compounds
form interstellar ices. Among the major heavy elements, carbon and oxygen are the most abundant in
the solid phase in the ISM. The total chemical abundances observed in both the gas and solid phase in
the ISM should agree with cosmic abundance estimates of the elements. However, in the ISM, carbon
and oxygen depletion from the gas phase is not consistent with the proposed abundances in the solid
particles. These have been referred to as the carbon crisis and the missing oxygen problem, respectively.
Although, the cosmic abundances are still in debate, there is a need to measure the abundance of elements
locked in the solid phase of ISM. For this purpose, there are some spectral features in the IR region thatcan be used. The 3.0-microns water ice O-H feature, the 3.4-microns aliphatic hydrocarbon C-H featureand the 9.8-microns silicate Si-O feature have particular importance as they are suitable for quantitative
studies. It is possible to estimate abundance of elements from optical depth of the related absorption
feature. Optical depths can be obtained by spectroscopic methods, but studying multiple sources over wide
ﬁelds requires long observation time. Photometric measurements with narrow-band ﬁlters can be used
to sample the spectrum. Photometric method can be applied to multiple sources in the ﬁeld of view. We
present a photometric method to measure the optical depth of the 3.0-microns water ice, the 3.4-microns
aliphatic hydrocarbon and the 9.8-microns silicate feature, by using JWST. This method will permit us tomap carbonaceous, siliceous dust and ice over wide ﬁelds. The resultant maps will reveal the abundance
distribution of the major solid phase elements and the structure of the solid phase of the ISM.

21 - Mechanisms of SiO oxidation and dust formation
Stefan Andersson
University of Gothenburg
In order to elucidate the eﬃciency of the formation of silicate dust particles it is necessary to study various
hypothesized reaction mechanisms in detail at the molecular level. We present calculations of reaction
mechanisms and reaction kinetics of the initial stages of the oxidation of SiO and silicon oxide cluster
growth. Molecular structures and energies were calculated using electronic structure theory, i.e., density
functional theory and coupled cluster methods. Reaction rate coeﬃcients were calculated using masterequation calculations based on calculated structures, energies and vibrational frequencies. The chemistryof a circumstellar environment of an oxygen-rich AGB star was simulated by introducing the calculated ratecoeﬀcients into a chemical reaction network. The limited formation of larger silicon oxide species in themodel seems to indicate that considering only silicon oxide molecules is not suﬃcient to initiate eﬃcient
formation of silicate dust particles.

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22 - Modelling the cold dust in nearby spiral galaxies with radiative transfer
Angelos NersesianGhent University
Cosmic dust grains are one of the fundamental ingredients of the interstellar medium (ISM). Despiteof their limited contribution to the total mass budget, dust grains play a signiﬁcant role in the physicaland chemical evolution of galaxies. Over the past decade, our knowledge on the cosmic dust in nearby
galaxies has increased substantially thanks to the availability of observational data from UV to far-infrared
wavelengths. However, one part of the spectrum, the mm range, has largely remained unexplored. We aim
to take advantage of the new, high-resolution data in the mm range observed with the NIKA2 instrument.
Combining these new observational data with our radiative transfer framework, would allow us to accurately
model the interplay between starlight and dust in a sizeable sample of spatially-resolved nearby galaxies. I
will present the methodology of our dust radiative transfer modelling and its application to a small group of
face-on spiral galaxies. I will highlight which modelling steps need to be improved, and how the new NIKA2
data would allow us to ﬁrmly characterize the physical properties of the very cold dust (<15K), as well as toquantify the importance of diﬀerent emission mechanisms in the mm.

23 - Modelling the dust cycle in local discs: unveiling the contribution of dust processes
at kpc scales
Marco Palla
Ghent University
INAF - OAS Bologna
In the literature, a large amount of work has been devoted to the study of the build-up of metals and dust
in galaxies. However, most of these analyses are based on global galactic properties. Therefore, spatiallyresolved studies are crucial to provide more detailed information on the evolution processes aﬀecting star
forming galaxies. In this talk we will concentrate on the DustPedia M74 / NGC628 disc galaxy, one of thebest examples for which spatially-resolved observations of fundamental physical quantities are available.
These quantities have been used to build a multi-zone chemical and dust evolution model for this source,
for which the star formation history parameters in each galactic zone are determined following a Bayesian
approach, i.e. by performing a MCMC ﬁtting on the stellar an gas density proﬁles for this galaxy. With thesestar formation histories, we then model dust evolution in diﬀerent galactic regions by testing a very wide
range of literature prescriptions about stardust production, dust growth within dense ISM and SN dust
destruction. We ﬁnd that by considering diﬀerent functional forms for both the dust accretion timescale andthe cleared dust mass per SN, we are able to account for the dust mass proﬁles observed in M74/NGC628.
These diﬀerent models envisage a diﬀerent current balance between destruction and accretion, in that bothan equilibrium and a dominion of accretion over destruction can equally reproduce the available constraints.
This outlines the strong degeneracy between the sub-grid recipes currently adopted in the literature inshaping the interstellar dust content in galaxies and the need for much deeper investigation on the role ofindividual processes contributing to the dust cycle.

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24 - A Novel sub-mm Galaxy Emission Line Survey - ANGELSTom Bakx
Chalmers University of Technology
ALMA has fundamentally improved the quality and resolution of studies of galaxies in the early Universe.
Its spectroscopic capabilities reveal the properties of the gas inside and surrounding galaxies from low
to very dense environments. However, often such observations require re-tuning, leading to overheads
that fundamentally limit ALMA’s spectroscopic capabilities to several tens of sources per project. Instead,I explore a method to use ﬁxed spectral windows that include as many lines as possible. We successfullytarget 85 lines within just 6 hours of observation time across Bands 3 through 8; a ﬁve-time improvementcompared to existing line surveys. This method can be extended to improve the science output of any futurecontinuum snapshots of sources with known redshifts that could, for free, pick up additional lines.

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25 - Plasma generation and characterization of ‘dense’ and ‘ﬂuﬀy’ hydrocarbon cosmic
dust analogs
Ramón J. Peláez
INSTITUTO DE ESTRUCTURA DE LA MATERIA (IEM-CSIC)In this work, we present two diﬀerent kind of hydrocarbon dust analogues produced with cold plasma in
RF discharges. These two materials have been extensively analyzed in recent years by our group. We havestudied their morphology, optical properties, and examined their behavior under realistic astrophysicalconditions, including energetic irradiations and desorption of volatiles, among others. Inductive or capacitive
RF discharges of reactive gases (CH4 or C2H2) are used to produce thin "dense” ﬁlms (1 g/cm3 ) or porous"ﬂuﬀy" deposits (0.007 g/cm3 ), respectively. Cross-section SEM images of thin ﬁlms reveal a compact
structure with minimal roughness, whereas the porous structures exhibit aggregates of nanoparticles withdiameters around 100 nm. The optical indices at 632.8 nm are similar for both materials, with a value of
n=1.7 and minimal absorption. The IR absorption spectra reveal the prominent band at 3.4 microns (CHxstretching), while the band structure at 6.2 microns (C=C stretching) varies depending on the material. The
thin ﬁlm is composed mainly of aliphatic compounds, whereas the porous structure exhibits a combinationof aliphatic and aromatic compounds. In both cases, the IR absorption spectra conﬁrm that these materials
are suitable cosmic dust analogs. Destruction rates of the 3.4 microns band are estimated under UV and keVelectron irradiations, simulating the eﬀects of the interstellar UV ﬁeld or cosmic rays. Preliminary resultson both materials reveal that cosmic rays alone cannot explain the observed disappearance of the 3.4
microns band in dense interstellar clouds. The interaction of monolayer ices of N2, CO, or CH4 on thinﬁlms and porous structures has been analyzed using thermal programmed desorption. The distributionof adsorption sites in the thin ﬁlms exhibits a single peak, while the porous structure reveals two peaks.
The higher-energy peak in the porous structure is attributed to the interaction of volatiles with aromatic
structures. Simulations of the desorption of volatiles from dust particles during the heating of cold stellar
cores indicate their potential involvement in gas-phase and surface chemistry processes. Additionally, theSpeciﬁc Surface Area (SSA) of cosmic dust plays a signiﬁcant role in its chemical reactions, heating, grain
growth, and optical properties. The SSA is estimated by monitoring changes in the RAIRS spectra of CO
condensed on a cold porous surface as the gas dosage increases. Preliminary results indicate that reducing
the size and increasing the porosity of nanoparticles leads to an increase in SSA.

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26 - Project SUPERPIG
Gent Frederick
Aalto University School of Science and Technology
In this talk I will present a new computational project on dust formation and processing in the ISM. This
projected, SUPERnova-induced Processing of Interstellar Grains (SUPERPIG), is a rather ambitious attempt
to push the boundaries of computational astrophysics. We aim to study how supernovae (SNe) interact
with the surrounding dusty interstellar medium (ISM) to answer, in particular, two questions: (1) are SNe net
producers or net destroyers of dust? (2) Is dust over- or under-abundant in newly formed cold molecular
clouds? We seek to answer these questions primarily by means of advanced HPC numerical simulations with
the Pencil Code (https://github.com/pencil-code). In addition, we will also study basic material propertiesof cosmic dust, how grains interact with electromagnetic radiation, and how this is related to ISM dynamics
and dust processing. The main novelty of SUPERPIG is an innovative use of zoom-in techniques primarily
based MPMD-coupling of the simulation code with itself, which involves time-evolving boundaries andremeshing aided by machine learning. With these new techniques we aim to cover, self-consistently, atleast 20 orders of magnitude in simulation length scales, including the large-scale ISM dynamics as well
as gas-dust interactions. New observational facilities (e.g. ELT, JWST) will provide a great opportunity todiscriminate between various scenarios for cosmic dust evolution, which is why project SUPERPIG represent
important and very timely theoretical research.

27 - Radiative transfer through 3D models of dust clouds around AGB-stars
Joachim Wiegert
Uppsala University
During the asymptotic giant branch (AGB) phase, low-to-intermediate mass stars (0.8 - 8 Msol) are characterized by strong mass losses. Important chemical elements (e.g. carbon) produced in their stellar cores aretransported by convection to the surface and by intense stellar winds to the interstellar medium. Crucial
for these outﬂows is the formation of dust. Silicate dust (e.g. Mg2SiO4) can form close to the surface ofO-rich AGB-stars and is a prime candidate for driving the wind since grains of sizes between 0.1 to 1 micron
experience strong radiation pressure due to scattering.
The EXWINGS team develops global radiation-hydrodynamical simulations with CO5BOLD to model theinterior of giant stars, outﬂow of gas, and formation of dust. The ﬁrst 3D ’star-and-wind-in-a-box’ models wererecently presented by Freytag & Höfner (2023, A&A 669, A155). I will present work on using these models tosimulate images and spectral energy distributions with the 3D radiative transfer program RADMC-3D. These
synthetic observables can be used to study the eﬀects of clumpiness, porosity, and other non-sphericalmorphologies in circumstellar environments. I will also show comparisons with other model setups (e.g.
spherical symmetric and point sources) that are common for radiative transfer simulations.

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28 - Serendipitous detection of the dusty Type IIL SN 1980K with JWST/MIRI
Szanna Zsíros
Department of Experimental Physics, University of Szeged, Hungary
Core-collapse supernovae (CCSNe) are unique astrophysical laboratories that play an essential role in thecosmic dust cycle and have been long considered one of the primary stellar sources of interstellar dust.
However, there are still numerous open questions regarding their contribution. The James Webb Space
Telescope (JWST) provides an exceptional opportunity to explore the dust and circumstellar (CSM) interactionin the close environment of CCSNe in details never seen before.
We present mid-infrared (mid-IR) imaging of the Type IIL SN 1980K with the JWST more than 40 yr postexplosion and the analysis of dust formation in its nearby environment. The SN is located in the close
so-called ’Fireworks Galaxy’ NGC 6946 (D∼7Mpc) and was captured in JWST/MIRI images taken of the ﬁeldof SN 2004et in the same galaxy. Its fortunate location and evolutionary stage make the SN a promising
candidate for studying the transitional phase between young SNe and older SN remnants. We also reanalyzed archive Spitzer data of the SN to investigate the late-time light curve and constrain upper limits on
shorter wavelengths.
We ﬁt both analytical and numerical dust models to the spectral energy distributions (SED), as well as
model the late-time optical spectrum obtained recently with Keck to draw conclusions on the physicalproperties of the assumed dust in the environment of the SN. The SED models reveal a surprisingly large
amount (Md ≃ 0.002 solar masses) of silicate-dominated dust at ∼150 K (along with a hotter dust/gas
component), while the optical line-proﬁle models disclose even larger (∼ 0.16 - 0.60 solar masses) dust
masses. Our conclusions suggest two possible scenarios for the SN 1980K observed with the JWST: i) we
may see pre-existing CSM-dust heated collisionally similarly to the equatorial ring of SN 1987A, or ii) themid-IR component of the newly-formed dust with much colder dust located in the ejecta.

8429 - Simulating dust dynamics in SPH and MFM hydrodynamical simulations
Giovanni Tedeschi Prades
University Observatory, Faculty of Physics, Ludwig-Maximilians-Universität München
Dust is a fundamental component of the interstellar medium, playing a major role in, for instance, theproduction of molecular hydrogen and the cooling of gas in galaxies. Although often tightly coupled with thegas, dust may also be an important dynamical element of the interstellar medium, constantly exchanging
momentum and energy with the gas, especially when considering larger dust grains in colder and less dense
environments. In particular, the study of protoplanetary disk evolution heavily relies on the dynamical
study of the dust component, which cannot be simply assumed to be perfectly coupled to the gas phase.
Simulating the dynamics of dust in hydrodynamical simulations is a complex computational task, that hasoften been solved by relying on simpliﬁcations. We, instead, implemented the so called One-Fluid model(Laibe, Price 2014) to simulate the dynamics of a mixture of gas and dust self-consistently, automatically
including the backreaction of dust onto the gas motion. This theoretical model was applied both to thestandard Smoothed Particle Hydrodynamics (SPH) framework as well as to the newly developed Meshless
Finite Mass (MFM) one. The latter is an hybrid computational method that aims to use the best out of boththe Lagrangian and Eulerian approaches to hydrodynamical simulations. The implementation we developed
for the MFM framework can be applied also to standard grid-based codes. We present the theoreticalaspects of the One-Fluid model and how it was implemented in this two diﬀerent hydrodynamical simulation
frameworks, as well as the performances of the code in three standard tests for dust dynamics (DUSTYBOX,DUSTYWAVE and DUSTYSHOCK). In addition, we show two possible application tests: the evolution of a
Kelvin-Helmholtz instability and a Cold Keplerian Disk in the presence of dust.

30 - Supernova shocks and dust destruction: what role does the environment play?
Nina Sanches Sartorio
Gent University
Supernovae are undoubtedly eﬃcient dust producers during the early stages of their evolution. However,
the ensuing forward and reverse shocks are also capable of destroying both the dust in the surrounding
interstellar medium and the newly formed dust in the ejecta, respectively. Thus, it is still unclear if supernovae
are net dust producers or destroyers. In order to shed light on the importance that the surrounding medium
has on the evolution of the supernova explosions, and thus in the net dust content, we ran a number ofmagneto-hydrodynamical simulations with the code Arepo and post-processed them with dust-processing
code Paperboats which includes a myriad of dust destruction mechanisms including sputtering, vaporizationand fragmentation. Each simulation has the supernova interacting with turbulent surroundings of varying
Mach numbers, average densities and magnetic ﬁeld strengths. This results in ﬁlamentary structuresthat can be very dense and can protect dust against destruction by the shocks. Furthermore, the shocks
themselves evolve in a non-uniform manner which results in a very distinct evolution from that expected toa shock traveling through a uniform medium. In this talk I will show how the evolution of the shocks, andconsequently the dust destruction, is sensitive to these parameters and compare these scenarios to thecase of the Cassiopeia A supernova remnant.

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31 - The eﬀect of dust opacities on winds of carbon-rich AGB stars
Emelie Siderud
Uppsala University
Stars on the asymptotic giant branch (AGB) lose a considerable part of their mass through stellar winds
driven by radiation pressure on dust grains. For carbon-rich AGB stars, the main wind-driving species
is amorphous carbon, which is a structurally complex material as evidenced by the various laboratory
extinction data available. In this study, we use size-dependent dust opacities and compare two optical data
sets to investigate how the wind characteristics as well as the grain and photometric properties are aﬀected.
Extensive grids of 1D hydrodynamical models, covering a wide range of stellar parameters, are calculated
and post-processed to retrieve synthetic observables. The results show that average mass loss rates do notchange signiﬁcantly, however, grain sizes and photometric properties are greatly aﬀected by the diﬀerent
dust opacities.

32 - Paradigmatic examples for testing models of optical light polarization by spheroidal
dust
Thomas Vannieuwenhuyse
ESO
We present a general framework on how the polarization of radiation due to scattering, dichroic extinction,and birefringence of aligned spheroidal dust grains can be implemented and tested in 3D Monte Carloradiative transfer (MCRT) codes. We derive a methodology for solving the radiative transfer equation
governing the changes of the Stokes parameters in dust-enshrouded objects. We utilize the Müller matrix,
and the extinction, scattering, linear, and circular polarization cross sections of spheroidal grains as wellas electrons. An established MCRT code is used and its capabilities are extended to include the Stokes
formalism. We compute changes in the polarization state of the light by scattering, dichroic extinction, andbirefringence on spheroidal grains. The dependency of the optical depth and the albedo on the polarizationis treated. The implementation of scattering by spheroidal grains both for random walk steps as well as
for directed scattering (peel-oﬀ) are described. The observable polarization of radiation of the objects
is determined through an angle binning method for photon packages leaving the model space as well as
through an inverse ray-tracing routine for the generation of images. We present paradigmatic examples forwhich we derive analytical solutions of the optical light polarization by spheroidal dust particles. These tests
are suited for benchmark veriﬁcation of MCpol and other such codes, and allow to quantify the numericalprecision reached. We demonstrate that MCpol is in excellent agreement to within 0.1% of the Stokes
parameters when compared to the analytical solutions.

86Code of conduct
All participants and organisers of the meeting must uphold the Code of Conduct. The conference is awelcoming and inclusive environment that will allow free expression and the exchange of scientiﬁc results.
We ﬁrmly reject any kind of abusive behaviour and will not tolerate any kind of harassment towards any
conference participants. All attendees are expected to behave professionally and treat each other withrespect for the duration of the meeting and in all activities related to it. We ask all participants to be
mindful of the cultural diﬀerences between participants. Any discriminatory behaviour against colleagues
on any basis such as gender, gender identity, race, ethnic background, national origin, religion, politicalaﬃliation, age, maritial status, sexual orientation, physical appearance, body size, disabilities or any otherreason will not be tolerated. Any personal attacks, or harassment of a violent or sexual nature will not betolerated. This applies during the conference as well as during any events and activities related to it, or on
any online platform associated with the conference. We ask and encourage all participants to engage inhealthy and respectful discussion, with a free exchange of ideas and scientiﬁc results. Ideas and resultsmust be respectfully discussed, based solely on their scientiﬁc merit.
If there is a breach in the Code of Conduct, we would encourage participants to feel safe and secure in
reporting this to any member of the LOC for the conference either in person or via their email• Theo Khouri (theo.khouri@chalmers.se),• Thiébaut Schirmer (thisch@chalmers.se).
• Martina Šimsová (martina.simsova@gu.se)• Tom Bakx (tom.bakx@chalmers.se)• Rasoul Hashemi (seyyedrasoulhashemi@gmail.com)• Theo Khouri (theo.khouri@chalmers.se)• David Gobrecht (gobrecht@chalmers.se)• Matthias Maercker (matthias.maercker@chalmers.se)• Gustav Olander (gustav.olander@chalmers.se)
For serious incidents, we encourage attendees to contact the local authorities (such as police, at 112 or 114
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87Covid-19 recommendations
In the interest of safety for one’s and others’ health, we ask all participants to follow all current recommendations in place in Sweden to combat the spread of Covid-19 and other diseases, including washinghands, staying at home if you feel unwell, etc. More information on those guidelines can be found here.
They include the recommendation that attendees should spread out when in the conference room during
the talks, and they should also make sure to take advantage of the well-spaced coﬀee break tables andposters; the aim is to avoid crowding.
We welcome people to wear masks if they feel that crowding or closeness cannot be avoided to a satisfactory
level. We would also suggest participants to engage in self-testing if they develop the symptoms of Covid-19,
and to alert the conference organisers if they test positive so that other conference attendees can be madeaware. Antigen tests can be found at any pharmacy throughout Gothenburg.

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