星形成ゼミ 2024/2/16 #372 30-38 辰馬 (理研数理創造プログラム)

30. AB Aur, a Rosetta stone for studies of planet formation (III): continuum observations at 2 and 7 mm
31. The Disk Orientations of Perseus Protostellar Multiples at 8 au Resolution
32. Ring Gap Structure around Class I Protostar WL 17
33. Cluster Formation in a Filamentary Cloud: The Case of the Stellar Cluster NGC 2316
34. The Role of Low-energy (< 20 eV) Secondary Electrons in the Extraterrestrial Synthesis of Prebiotic Molecules
35. The 3D Kinematics of the Orion Nebula Cluster II: Mass-dependent Kinematics of the Inner Cluster
36. Chemistry of Complex Organic Molecules in the V883 Ori Disk Revealed by ALMA Band 3 Observations
37. Insights into the rst and second hydrostatic core stages from numerical simulationsfi

38. Surveys of clumps, cores, and condensations in Cygnus-X: SMA observations of SiO (5−4)

AB Aur, a Rosetta stone for studies of planet formation (III): continuum observationsat 2 and 7 mm

Pablo Rivière-Marichalar, Enrique Macías, Clément Baruteau, Asunción Fuente, Roberto Neri, Álvaro Ribas,
Gisela Esplugues, David Navarro-Almaida, Mayra Osorio, Guillem Anglada F Observational constraints on dust

properties in protoplanetary disks are key to better understanding disks’ evolution. We continue our exploration of
the protoplanetary disk around AB Aur by characterizing its dust properties. We present ALMA observations at 2.2mm and VLA observations at 6.8 mm. Together with previous ALMA and NOEMA observations at 0.87 and 1.1
mm, these observations are used to compute global spectral index profiles as well as spectral index maps. On theinterpretation side, we present the results of a simple isothermal slab model to help constrain dust properties along
the ring of continuum emission. We also present results of dust radiative transfer calculations based on a disc-planet
hydrodynamical simulation to explain how the azimuthal contrast ratio of the ring emission varies with millimeter
wavelength. The spectral energy distribution and the radial profiles of the spectral index indicate that the radiationfrom the compact source towards the center is not dominated by dust thermal emission, but most likely by free-freeemission originating in the radio jet: it constitutes 93% of the emission at 6.8 mm, and 37% at 0.87 mm. The
protoplanetary disk has a typical spectral index of 2.3. We estimate a dust disk mass of 8⇥10 5 M which, assuming
a mean gas-to-dust ratio of 40, gives a total disk mass of 3.2⇥10 3 M . The azimuthal contrast ratio of the ringoutside the millimeter cavity is smaller at 2.2 mm than at 1.1 mm, in agreement with previous findings. The VLA
image shows several knots of 5 emission all along the ring, which are consistent with the ring emission being nearly
axisymmetric at that wavelength. The decrease in the azimuthal contrast ratio of the ring emission from 0.87 to 6.8mm can be explained by a dust-losing decaying vortex at the outer edge of a planet gap.

• 新しく観測したALMA 2.2 mmとVLA 6.8 mmに、これまでのALMA 0.87 mmとNOEMA 1.1 mmを足した
The Disk Orientations of Perseus Protostellar Multiples at 8 au Resolution
K. Reynolds, John J. Tobin, Patrick
D. Sheehan, Sarah I. Sadavoy,
Leslie W. Looney, Kaitlin M.
中心のコンパクト源からの放射は、radio
jetの中に起因するfree-freeemissionであることがわかった•Nickalas
Kratter, Zhi-Yun Li, Dominique M. Segura-Cox, Nathan A. Kaib F We present a statistical characterization
Aurの典型的なスペクトル指数は2.3だった•of原始惑星系円盤AB
circumstellar disk orientations
toward 12 protostellar multiple systems in the Perseus molecular cloud using the
Atacama Large Millimeter/submillimeter Array at Band 6 (1.3 mm) with a resolution of 25 mas (8 au). This exquisite
2
resolution enabled us to resolve the compact inner disk structures surrounding the components of each multiple system

with the ring emission being nearly axisymmetric at thatfrom 0.87 to 6.8 mm can be explained by a dust-losing
AB Aur, a Rosetta stone for studies of planet formation (III): continuum observations at 2 and 7 mm
(Rivière-Marichalar et al.) Rivière-Marichalar et al.: AB Aur, a Rosetta stone for studies of planet formation (III)rmation背景

光学的に薄いcontinuum
emissionを仮定すると、•
ze distribution. Assuming opti-

↵
about
the
dust
grain
size
distribution.
Assuming
optithe spectral
index (S ⌫ / ⌫ ) は、Rayleigh-Jans領域でis
スペクトル指数↵n )continuum
emission,thespectral
index
(S
/
⌫
)
is
⌫
in the Rayleigh-Jeans regimeo thedust
dust opacity
opacity (⌫ / ⌫ )とα=β+2の関係性をもつ
in the Rayleigh-Jeans regime
micron-sizedgrains
in
the
ISM,
↵=
2. For the sub-micron-sized grains in the ISM,
サブミクロンサイズのISMだとβ~1.7
ust
grainsgrow
insize(Miyake•nd becomes smaller as dust grains grow in size (Miyake
g zeroinprotoplanetarydisks.
gawa1993),
approachingzero
in protoplanetary disks.
• 原始惑星系円盤ではβ~ 0（ダストサイズ分布を反映している）
eters
such toasinterferometers
ALMA, NOEMA,ys, thankssuch as ALMA, NOEMA,AB Aur(遷移円盤)s can
be computed
at a great
anVLA,
spectralindex maps
can becomputed at a great antudy
radialandemission:
azimuthalvarisolution
allowing
us to study
radialand azimuthal vari~ 370
auまで• continuum
foughout
the spectral
index(Pérez
throughout
the disk
et al.the disk (Pérez et al.
100et
auの幅のcavityと、そのすぐ外側に非対称リングがある• ~Pinilla
015;
etal.
al.2015;
2015; CarrascoCasassus et al. 2015; CarrascoCasassus
z et
al.
2019;
Macı́as
et
al.
2019,
2021;
Sierra
et
al.
2021;
l.
2019,
2021;
Sierraetal.
2021;→ 大質量惑星 (2木星質量@98 au) によるギャップの外縁でのal. 2022).

渦の減衰で説明できる可能性がある (Fuente+2017)

Aur is an HAe star located at ⇡162.9 pc from the Suntedat⇡162.9
pc
from
the
Sun
→
すばる望遠鏡とHSTの観測によると、93
auに原始惑星がollaboration 2018) that is surrounded by a transition disk
★原始惑星Fig. 1. Top left: ALMA map at 0.87 mm. Top right: NOEMA map at 1.1 mm. Bottom left: ALMA map at 2.2 mm. Bottom right:
surroundedbyatransition
disk
as beenstudied in great detail.
The source
has been exVLA map at 7 mm. The light grey contours in the bottom right panel depict 5 continuum emission at 2.2 mm from our ALMA
あるとの主張がある(Currie+2022,
Zhou+2022)
map. The grey dashed line marks the position of the cm jet detected by Rodrı́guez et al. (2014). The green star marks the position
detail.
Thesourcehas
been
exof the tentative protoplanet proposed by Currie et al. (2022). The synthesized beam is shown in the bottom-left corner of each map.
y observed at millimeter wavelengths using single-dishContour levels in the 0.87, 1.1, and 6.8 mm maps are 5 , 10 , 25 , and 50 . The 2.2 mm map only shows 5 , 10 , and 25 levels.
using single-dish
The map of the VLA emission at 7 mm also includes 3 contour levels. In all maps, the color bar indicates flux in mJy/beam.
eswavelengths
and interferometers.
Such observations covered con3
Suchobservations
emission
as well ascovered
emissionconfrom molecular species.

Rivière-Marichalar et al.: AB Aur, a Rosetta stone for studies of planet formation (III)AB Aur, a Rosetta stone for studies of planet formation (III): continuum observations at 2 and 7 mm
(Rivière-Marichalar et al.)
ミリ波でのSED (スペクトルエネルギー分布)• 中心のコンパクト源: 1.1±0.1（図では1.0±0.2？）• 外側の円盤: 2.3±0.1（原始惑星系円盤の値と整合的）
1次元等温ダストslabモデル-p, an(a)∝aµm, p=3.5, DSHARPの組成• 仮定: ダストサイズ分布
min=0.01
Rivière-Marichalar et al.: AB Aur, a Rosettastone for studies of planet formation (III)dust trap• ダスト面密度Σdと0.1 mm<amax<10Fig.cmを求めた
4. Radially averaged azimuthal profiles of the NOEMA and

ALMA maps at 0.87mm (solid blue curve), 1.1 mm (solid black
curve), and 2.2 mm (solid red curve) and of the ↵0.87mm 1mm 2mm
spectral index (dashed curve). To compute the azimuthal profile
the maps were deprojected with PA=-37 and i=24.9 . The 0.87
and 2.2 mm maps were convolved with the beam of the 1 mm
map for comparison purposes.

3.3. Azimuthal profiles

We show in Fig. 4 the radially averaged azimuthal profiles of
our ALMA and NOEMA continuum maps at 0.87, 1.1, and 2.2mm.
The profiles
computedby averaging
thecurve
intensity
Fig. 10. Results from fitting the azimuthal profiles of continuum
emissionwith 1Dwere
isothermalslab models.
The blue
depictsat
eachthickazimuth
betweenr = 50a smoothed
au and r version= 140 after
au. Theprofilethe best value at each azimuth and for each parameter, while theblack curve
represents
applyingafor the ofVLA
map
at 6.8mm
is shaded
not shown,since
we lack
Savitzky-Golay filter with a window length of 51 and a polynomialorder
3. Thedark
grey
regions
represent
the emis16%
and 84% confidence levels. The light grey curves represent asionsmoothed
versionof theTheconfidence
levels after
applying
the same
at mostazimuths.
radial averages
werecomputed
only
Savitzky-Golay filter. The red vertical dashed lines show the along
approximate
azimuthal
extent oftothe
dustfortrapvisualas tracedby the 0.87,
the disk.
Furthermore,allow
comparison
and1.1, and 2.2 mm continuum maps.
before computing the azimuthal profiles,
the maps at 0.87 and4
2.2 mm were convolved with the beam of the 1.1 mm map. The

Fig. 5. Spectral energy distribution at mm wavelengths. Top: forthe inner source. Bottom: for the outer disk. The blue dots represent our observations at di↵erent wavelengths, while the blackline is a linear fit to the data.

et al.: AB Aur, a Rosetta s
AB Aur, a Rosetta stone for studies of planet formation (III): continuum observations at 2Rivière-Marichalar
and 7 mm
W
(Rivière-Marichalar et al.)21次元等温ダストslabモデル

スペクトル指数に関する議論• 平均最大ダストサイズ:• 他のデータも合わせたsub-mm & mm: 2.5±0.1

1.5±0.3 mm (dust trap内)
2.2±0.8 mm (円盤全体)
2.6±0.5 mm (dust trap以外)

ies of planet formation (III)※ただし不定性大きい
dust trap

2
r
m
t

u
W
a
d
m
c
r
c
r
o

→ ダスト熱放射（円盤）が占めている• 他のデータも合わせたcm: 0.6±0.3→ 中心からのfree-free emissionが占めている• 中心からのmm波放射はダスト熱放射とfree-free emissionの足し合わせになっている

a
o
i
o
t
t

• 中心のcm tを除いたmmデータ: 2.1±0.3→ 外側の円盤より中心のほうが大きなダスト？

t
o
u
c

(Discussionの本文は逆になっているが…）

fi

5

Fig. 11. Top: spectral energy distribution from the sub-mm to cm
wavelengths. The thick red line depicts a fit to cm data, while
the blue one shows a fit to sub-mm and mm data. The thickblack curve shows the combined fit. Blue dots are observations
from this paper (mm data) and the literature (sub-mm and cm).
Black triangles are fluxes from the central source alone. Bottom:
spectral energy distribution at mm wavelengths for the compact
source towards the center after subtracting the free-free contribution.

a
p
u
T
(
p
o

A
p
R

Chemistry of Complex Organic Molecules in the V883 Ori Disk Revealed by ALMABand 3 Observations

Yoshihide Yamato, Shota Notsu, Yuri Aikawa, Yuki Okoda, Hideko Nomura, Nami Sakai F Complex organic

molecules (COMs) in protoplanetary disks are key to understanding the origin of volatiles in comets in our solar
system, yet the chemistry of COMs in protoplanetary disks remains poorly understood. Here we present Atacama
Large Millimeter/submillimeter Array (ALMA) Band 3 observations of the disk around the young outbursting star
V883 Ori, where the COMs sublimate from ices and are thus observable thanks to the warm condition of the disk.
We have robustly identified ten oxygen-bearing COMs including 13 C-isotopologues in the disk-integrated spectra. The
radial distributions of the COM emission, revealed by the detailed analyses of the line profiles, show the inner emission
cavity, similar to the previous observations in Band 6 and Band 7. We found that the COMs abundance ratios withrespect to methanol are significantly higher than those in the warm protostellar envelopes of IRAS 16293-2422 andsimilar to the ratios in the solar system comet 67P/Churyumov-Gerasimenko, suggesting the eﬃcient (re-)formationof COMs in protoplanetary disks. We also constrained the 12 C/13 C and D/H ratios of COMs in protoplanetary disks
for the first time. The 12 C/13 C ratios of acetaldehyde, methyl formate, and dimethyl ether are consistently lower (⇠20-30) than the canonical ratio in the interstellar medium (⇠ 69), indicating the eﬃcient 13 C-fractionation of CO.
The D/H ratios of methyl formate are slightly lower than the values in IRAS 16293-2422, possibly pointing to thedestruction and reformation of COMs in disks. We also discuss the implications for nitrogen and sulfur chemistry inprotoplanetary disks.

• ALMA Band 3でCOMs (複雑有機分子)が昇華できる温かい条件を満たすoutbursting starを観測した
Insights into the first and second hydrostatic core stages from numerical simulations• 13C同位体を含む10種の酸素を含むCOMsを同定した
Alison K. Young F The theory of how low mass stars form from the collapse of a dense molecular cloud core has
been well-established for decades. Thanks to significant progress in computing and numerical modelling, more physicalmodels have been developed and a wider parameter space explored to understand the early stages of star formation• メタノールに対するCOMsの存在量比は、温かい原始星エンベロープよりも非常に高く、••

more fully. In this review, I describe the expected physical properties of the first and second core stages and how
太陽系彗星67Pに似ていることがわかった
原始惑星系円盤でのCOMsの(再)形成の影響を示唆している
the inclusion of diﬀerent physics aﬀects →thosepredicted characteristics. I provide an overview of chemical models andsynthetic observations, looking towards the positive identification of the first core in nature, which remains elusive.
However, there are a few likely candidate first cores, which are listed, and I briefly discuss
the recent progressin
アセトアルデヒド、ギ酸メチル、ジメチルエーテルの12C/13C比は星間物質(~69)よりも低い(~
20—30)ことがcharacterising the youngest protostellar sources. Chemistry will be instrumental in the firm identification of the firstcore so we require robust theoretical predictions of the chemical evolution of protostellar cores, especially of the first
わかった → 効率的なCOの13C分別を示唆しているand second core outflows. Looking ahead, simulations can shed light on how the protostellar collapse phase shapes
the evolution of the protostellar disc. Simulations of dust evolution during protostellar core collapse show there is
ギ酸メチルのD/H比が原始星エンベロープよりもわずかに低く、円盤でのCOMsの破壊と再形成を示唆している
6 the centre of the core. Chemical models show that thesignificant enhancement in grain size and abundance towards

Chemistry of Complex Organic Molecules in the V883 Ori Disk Revealed by ALMA Band 3 Observations(Yamato et al.)
背景

• 彗星の氷の起源: 星間物質？
例えば原始星エンベロープの温かい内側や彗星で、HDO/H2OよりもD2O/HDOが高い→ 水は化学的リセットを受けておらずISM起源• 有機分子(~ 100 Kで昇華)のうち特に6個以上の原子と炭素を含む分子を複雑有機分子(COMs)と呼ぶ
6

Yamato et al.

I (mJy beam 1 )0V883 Ori (FU Orionis天体)

1.0

3

6

9

12

3.3 mm Continuum

CH3 OH2 1,1 –1 1,0 E vt = 0
Eup = 28 K

0.5

• 大きなoutburstをするケプラー回転円盤• outburstの期間(~ 100 yr)は典型的な気相でのCH3 OCHO
85,3 –75,2 E vt = 0
Eup = 38 K

CH3 CHO
52,4 –42,3 E vt = 1
Eup = 226 K

CH3 OCH3
163,14 –154,11
AA, EE, EA, AE
Eup = 136 K

50

0.0
0.5

80 au

1.0

化学反応よりも短い

1.0

c-C2 H4 O 129,4 –128,5
Eup = 169 K

80 au
t-C2 H3 CHO 113,9 –103,8
Eup = 47 K

s-C2 H5 CHO
125,7 –124,8 E, A
Eup = 53 K

( )

0.5

→ 化学反応の影響を受けずに円盤の氷の組成のまま

80 au

80 au
CH3 COCH3
176,11 –175,12 EE,
177,11 –176,12 EE
Eup = 111 K

80 au
OCS 7–6
Eup = 16 K

20

0.0
10

0.5

昇華したCOMsを観測することができる

80 au

1.0
1.0

• COMsの放射は40—120 au (内側にcavity)→ 強いダスト連続波放射が≤ 40 auのCOMsを隠している？

30

I (mJy beam 1 km s 1 )

40

0.5

0.0

0.5

1.0 1.0

80 au
0.5

0.0

0.5

1.0 1.0

80 au
0.5

0.0

0.5

1.0 1.0

80 au
0.5

0.0

0.5

1.0 1.0

80 au
0.5

0.0

0.5

1.0

( )

Figure 1. The 3.3 mm dust continuum image (left top) and the velocity-integrated intensity maps of the molecular line emission (others) in theV883 Ori disk. The velocity range for integration are ±3.5 km s 1 with respect to the source systemic velocity vsys = 4.25 km s 1 (Tobin et al.
2023) including CH3 OCH3 and CH3 COCH3 , where multiple blended transitions are integrated together. The molecular species, transitions,and upper state energy levels are indicated in the upper-left corner of each panel. The black contours start from 5 with steps of 2.5 , where
are the noise level of each map measured on the emission-free region, spanning = 1.8–4.4 mJy beam 1 km s 1 depending on the maps. The
synthesized beam and a scale bar of 80 au are shown in the lower left and right corner of each panel, respectively.

7 by a factor of ⇠ 2 or less. Although suchsities are lower

The results of the fits are summarized in Table 3. The de-0which is consistent with the higher-resolution Band 6 profilele the spatial extent of the emission is consisvsys(Tobin et al. 2023). This suggests that the bulk of the obvious ALMA observations in Band 6 and Band
2
0
2
4
8
10
2
0
2
ofTobinComplex
Organicserved
Moleculesin the V883
Ori DiskbyRevealedby ALMA
Band
3 61Observations
Band 3 emission
can be explained
emission from↵ et al. 2018;Chemistry
Lee et al. 2019;
et al. 2023)
vLSRK (km s )the 40–80 au region,and that the
he di↵erence in the beam size, the central emis(Yamato
etinneral.) emission cavity likely
Figure 3. Line profiles of CH3 OH 2 1,1 – 1 1,0 E vt = 0, CH3 CHO 5
exists even in the Band 3 emission as well.
seen in the Band 6/7 data are not detected in1
graydotted
line
marks
the
systemic
velocity(4.25
kms). The vertical
観測結果
00
t the current spatial resolution of ⇠ 0. 3.
channel based on the maximum velocity of Keplerian rotation in Equa

There s-C
are noHsignificant
emissionat the velocity
channels
which corresp
13CH OCHO,
13CHO
3.3.
ColumnDensity
Retrieval
同定(10種):
CH
OH,
CH
CHO,
CH
OCHO,
CH
OCH
,
c-C
H
O,
CH
COCH
,
t-C
H
CHO,
CHO,
CH
O
• 3.2.2.
3
3
3
3
3
2
4
3
3
2
3
2
5
3
3
Line Profile Analysis
10
To derive the disk-averaged column density of each 8
k emission
isonlymarginallyspatially
resolved,
13
13
暫定的に同定(6種): CH3 CHO, CH3OCH
CH OH•
3, CH2DOH, CH2DCHO, CH3CDO, C2H3CN
species, we first employ a simultaneous fit of an LTE spectral
to directly infer the distribution of the emission
CH CHO
8 emission cavity seen in
et al.
modelYamato
to theextracted spectra, taking into account the specregion,
particularly
the
OCSとSOの遷移も検出•CH OCHO
6
2tral blending and line optical depth. The same spectral model
6

I (Jy au 2 km s 1 )3
3
3

line observations in Bands 6 and 7120(van’t Ho↵
au
120 auis used120asfor
line
identification(see
AppendixEfordetails),
Lee et al. 2019; Tobin et al. 2023). Alternatively,au
120 au4
where all (tentatively) identified species as in Section 3.1 arerectly probe the emission in the40 auinner region,
40 au
considered.
We40 auexcluded the opticallythick(⌧ > 0.2) tran40 au
120 au120
au
spatially resolved in the velocity-integrated in2
40 au
40 au
sitions
from
the
fit
(except
for
OCS
which
only
have
one
deau
10 au
10 au
10 au
(Figure 1), from the line 10profile
by assuming 10 au 10 au
tected transition) to minimize the optical depth e↵ect; the secs. For the line emission of gas in a Keplerianvv
v
0
lection
is
based
on
the
optical
depth
at
the
line
centerinthe, the high-velocity components with respect to(km s )
50
100
150
200
best-fit model for line identification (Section 3.1). Specifi- 0
velocity, or the line wings, purelyv containinR (au)Figure 3. Line profiles of CH OH 2
–1
E v =cally,
0, CH CHO
5 excluded– 4 E v = the0, andtransitions
CH OCHO 7 –of
6 abundant
E v = 0. The verticalwespecies(e.g.,
out the emission fromgraythe
inner
region.
dottedline marks
the systemicMore
velocity (4.25 km s ). The vertical blue dashed lines indicate the corresponding disk radii at each velocity
based on the maximum
velocityof Keplerian rotationin Equation
The horizontal
grayCHdashedline indicatesthe zero-flux
CH3 OH,
CH(1).
andwitha largelevel.
Einstein
FigureA4. Reconstructed radial intensity profiles of CH3 OH (blue),
3 OCHO,
3 CHO)
he空間分布maximum velocitychannelofKeplerianrotationasaThere are no significant emission at the velocity channels which corresponds to inside ⇠ 40 au radius.
CH3exCHO (orange), and CH3 OCHO (green) transitions. The horicoefficient and a relatively low upper state energy. The
10
isk radius (vmax (r)) can be written
asplane. Therefore, while the depression of the emission in the zontal gray dashed line indicates the zero-intensity level. The gray
• 3つの明るい遷移のダブルピークがケプラー回転と一致
8r
are indicatedin Table
5 cavityin Appendix
C.
CH3 OHcluded transitions
innermost regionis robust, the actual
emissionsizes
dashed curve shows the radial intensity profile of CH3 OH transitionGM?
CH3 CHOinBand
3emissionareratheruncertain.
In
addition,
tranTheopticaldepth
thresholdof
0.2
isdeterminedtominimize
v
(r)
=
sin
i,
(1)
CH3の放射は40—80
auからのもの
6 と比較 → Bandsitions with di↵erent
optical depths or upper state energies, in Band 6 created by deprojection and azimuthal averaging on the
3 OCHO• maxr
the optical depth
e↵ect
while
leavinga sufficientnumberofhigher-resolution(⇠ 0.00 1) velocity-integrated intensity maps (Tobin
which could
trace thedi↵erent
disk heights,
may have di↵erent emission distributions.
etdepthal. 2023). The Band 6 intensity profile is normalized by its radial
4? +4.3transitions
available
for
the
fit.
When
higheropticalhe •gravitational
constant,Misthecentralstel励起温度は106.7-3.8 K → COMsの昇華温度(~ 100 K)と類似
peak being matched to the radial peak of the Band 3 CH3 OH profile.
physicalchemical structureof the innermostd i is the inclination of the disk. The V883 Ori
threshold of 4.2.
⌧ >The0.4
is andadopted,the resulting
columndenCH3 OH 2 1,1 – 1 1,0 E vt = 0

CH3 CHO 52,3 – 42,2 E vt = 0

CH3 OCHO 76,1 – 66,0 E vt = 0

sys

sys

sys

40

F (mJy)

30

20

10

0

2

0

2

4

6

8

10

2

0

2

4

6

8

2,3

2,2

t

10

2

0

2

4

6

8

10

1

LSRK

3

1,1

1,0

t

1

3

3

6,1

6,0

t

I (Jy au 2 km s 1 )6region of the V883 Ori disk

• Band 3の放射は40—80 auからのもの → ただし、分子輝線は円盤表層から来ている可能性があり、Our line profile analyses suggest that the COM line emiswhich is consistent with the higher-resolution Band 6 profile2

0sion in Band 3 also shows the inner emission cavity at . 40 au
radius. Here we discuss the possible origins of the emission
cavity and the associated physical and chemical structures of8
the V883 Ori disk.

そこではケプラー速度が赤道面よりもわずかに小さくなる
0

50

100

R (au)

150

200(Figure 4). Therefore, it is likely that the emission observedin Band 3 mainly traces the components outside the emission

V883 Ori Band 3

11

Chemistry of Complex Organic Molecules in the V883 Ori Disk Revealed by ALMA Band 3 Observations(Yamatoet al.)IRAS 16293 A
chemical composition of disks can be inherited
to comets

HCO + CH3 ! CH3 CHO,

(3)

CH3 + CH3 O ! CH3 OCH3 ,(5)• ~ 30—50 Kのダスト表面では重いラジカルの拡散が効率的→ COMsの生成

HCO + CH3 O ! CH3 OCHO,

9

(4)

O
H
s-

C

2H
5C

H
2H
3C

t-

C

C
c-

O
3C

O

2H
4O

H
C

C
3O

H
C

3

O
H

H
3C

H
C

H

4

C

10

3

3

H

10

C

2

3O

10

H

1

C

10

IRAS 16293 B
67P
IRS 48
V883 OriO

N (X)/N (CH3 OH)

without drastic chemical reprocessing.
Band 3のCOMsのemission
cavity(≤40au)の説明In general, the formation of COMs are thought to occur
mainly via reactions on dust grain surfaces (Herbst & van
1. ダスト連続光放射が強すぎて、
Dishoeck 2009, and references therein). In the cold tem円盤内側の輝線放射を検出することができない
perature region (. 10 K), the CH3 OH ice forms via efficienthydrogenation of the CO ice (e.g., Tielens & Hagen 1982;
2. ≤ 40 auの分子が中心の原始星からの強いUV/X線放射によってWatanabe & Kouchi 2002; Watanabe et al. 2003). Therefore,
the
CH
OH
ice
forms
in
cold
molecular
cloudsand3
破壊されているcould be delivered to protoplanetary disks. On the other
hand, di↵usion of heavier radicals (e.g., CH3 , CH2 OH, andCOMsの化学存在量比
CH3 O), formed via the UV/X-ray/cosmic-ray-induced pho• CH3OHよりも複雑なCOMsは原始星エンベロープから
tolysis and hydrogen abstraction of simpler molecules including CH3 OH, are efficient on the warmer (⇠ 30–50 K)
原始惑星系円盤までの進化段階で効率的に形成する
dust grain surfaces. More complex molecules such as
CH3 CHO, CH3 OCHO, CH3 OCH3 , and CH3 COCH3 could• 円盤の化学組成は彗星に受け継がれる可能性がある
thus be formed via radical-radical reactions. For exam• 一般的にCOMsはダスト表面反応で形成する:
ple, theoretical and experimental studies (e.g., Garrod &Herbst 2006; Chuang et al. 2016) have shown that CH3 CHO,
OH氷はCO氷の効率的な水素化で形成し、• 分子雲(≤ 10 K)でCH
3
CH3 OCHO, CH3 OCH3 , and CH3 COCH3 are mainly formed
via following reactions,
円盤に運ばれる

100

Figure 6. Comparison of the COM abundance ratios with respect
to CH3 OH among di↵erent evolutionary stages including the V883
Ori disk measured in the present work. The data point with a downarrow indicate an upper limit. We compiled the literature values forthe protostellar envelopes of IRAS 16293-2422 A/B (Lykke et al.
2017; Jørgensen et al. 2018; Manigand et al. 2020, 2021), the comet
67P/C-G (Rubin et al. 2019; Schuhmann et al. 2019), and the IRS
48 disk (Brunken et al. 2022). Note that while all the cometary
values are limited to be upper limits because cometary measurement(mass spectra) cannot distinguish the isomeric molecules with thesame mass (e.g., CH3 CHO and c-C2 H4 O pair and CH3 COCH3 ands-C2 H5 CHO pair), the upper limit of CH3 CHO in the IRS 48 disk isdue to non-detection.

V883 Ori Band 3

Chemistry of Complex Organic Molecules in the V883 Ori Disk Revealed by ALMA Band 3 Observations
CH OCH / CH OCH(Yamato et al.) Yamato et al.
12
CH OCHO/ CH OCHO
3

5

3

3

13

3

14

13

13

3

3

4
CH OCHO/CH O CHO
Yamatoetal.
1213COMsの同位体比:Zhang
C/ et C比CH CHO/ CH CHO
3
al. 2017). They suggest that the gas-phase isotopeWe note that the elemental abundance
ratiosofC/
CH CHO/CH CHO
Cataldi 20—30であり、local
etexchange
al. 2021,reaction,
see also Aikawa
et al.69よりも低い2022), no meaFigure
8 comparecolumnbecome
densitylower
ratios withof COMs
2
C/H in the D/Hgas phaseincreasing i
ISMの~• 12C/13C比は~surements of COM deuteration exist so far except for the
in 1the V883 tion
Ori diskand 67P/Crate within thethosediskin(&IRAS
10 1716293B
s 1 ; Eistrup
et al. 2016; Sc
13 + 1212 +
13
気相での同位体交換反応:
C
+
CO
!
C
+
•
G.(7)
The upperetlimitof COM
D/H
obtainedinmay
the V883
CH2 DOH/CH3 OH ratio in the V883 Ori disk CO(Lee+ et E,al.
al. 2018;
Notsu
et ratiosal. 2020),
which
inhibit the in
0
0
20
60
80
13 40than the2019).
Ori
disk
are
lower
ratiosin
IRAS
16293B.
As
the
of
CO
abundancevia
theexchange
reaction(Equat12
13
N (X C)/N (X C)→ 気相でC/O比が高ければ(>
1)、
CO/
CO比が低くなる( E ⇡ fractionation
35 K; Langerisetinitiatedal. 1984;
Furuyaet al. 2011), D/Hwith ratios are very sensitive to the formation temperature,
The deuteriumby thedeuteration
Figure 7. Kernel density estimate(Woods(KDE) of the posterior
probability density
distributions ofcolumn density ratios of CC-isotopologues& Willacy2009).
Alternatively,
itto may
be po+
for CH
CHO, CH
OCHO, and CH OCH . Two isomers of C-isotopologues are observed for CH CHO and CH OCHO. The probability
the
help
of
the
high
gas-phase
C/O
ratio
(>
1),
would
lead
to
of
H
with
the
gas-phaseion-molecule
reaction,
the
lower
D/H
ratio
of
COMs inThethe
V883
Ori disk
mayenhances
beline. We notethD/H比density is normalized by the peakthat
being unityand destructiono↵set for visual clarity. ofISMvalue of 69 is marked bygrains
the vertical dashed3
thecarbonaceousthat the C/
C ratios of CH CHO and CH OCH are based on the tentatively detected transitions of C-isotopologues, and therefore shouldsuch a low 12 CO/13 CO ratio in the warm molecular layer.
The
explainedbyabundance
the formation
theV883onOri Band3 lukewarm (⇠ 30–50 K)
15
be considered as lower limits.
and
C/O
ratio
in
protostellar
disks
and
env
+
+
12 13
H
+
HD
!
H
D
+
H
+
E.
(8)
気相での発熱反応:•22same mechanism
would
explaintheobservedlow
C/ C
ra- grainIRASsurfaces
CHhand,DOH/CH OH
dust
within
the
disk.
On
the
other
the
3
16293
B
V883
Ori
67P/C-G(e.g., Wei et al. 2019; van ’t Ho↵ etCHal.CDO/CH
2020),
althougCHO
13
tio in COMs if the C-rich
CO is incorporated into theD/H
ice ratio低温？
of CH3 OH少し温かい？
(not the column 低温？
density ratio,
but theCH DCHO/CH
CHO+
unclear whether
destructionof carbonaceous
grain→ 低温では逆反応が抑制され、H
Table 4. C/ theC Ratiosof COMs
CH OCDO/CH OCHOThis reaction is exothermic ( E2D⇡ が多くなる
230 K; e.g., Millar et al.
D/H ratio after the statistical correction)CHinDOCHO/CH
67P/Con dust grains in the disk midplane via vertical mixingelemental
andOCHO
cientlyoccurs
in
the
outer
cold
regionwhere1989), and therefore at the low temperature (. 30 K) theV883 Ori (this work) IRAS 16293Aa IRAS 16293Bb 67P/C-Gc CO and C
G has been measured to be 0.71–6.6 % (Drozdovskaya et al.
freeze-out (Furuya et al. 2022), from which• D/H比の違いは、形成環境の温度の違いを反映している？
+ the COMs suchMethanol
form (. 100 K).
backward reaction is suppressed, enhancing the H2 D abunOH/ CH OHreduced to a— CH2 DOH/CH
65 ± 27 3 OH —91 ± 102021),CH whichratio (0.021–
as CH3 CHO and CH3 OCHO are synthesized via hydrogena13
In
the
comet
67P/C-G,
only
the
CH
OH/
CH3 OH
Acetaldehyde
dance in the gas phase. In dense cold regions such as prestel3→ 67PのCOMsはエンベロープから受け継がれたが、with thein —IRAS 16293B,
pointCHO/CH CHO(29 values)
67—
tion and radical-radical reactions (Equations+ (3)–(6)) on 0.20),
dust CHconsistent
has
(91 ±
et— al. 2020a, s
lar cores, a freeze-out of CO, a main reactant with H2 D , furCH CHO/ CH
CHO been measured> 4.2— 10; Altwegg
67
ing
to
the
prestellar
originsofCHOH(Drozdovskaya
et
al.
3
grain
surfaces.
MethylFormate13
V883 OriのCOMsは少し温かい(~
30—50
K)環境で(再)生成した？
ther enhances the fractionation (e.g.,
Roberts& Millar 2000).12
ble
4),
showingnoC
fractionation
from
the
solar
CH
OCHO/CH
O
CHO
23
75
±
32
(41)
—
13
2021).
The D/H ratios of di↵erent COMs measured in the 12 13Analternative
mechanism
that
could
alter
the
CO/
CO
+
CH OCHO/CH OCHO23 Ori disk with&of the COM
D/Hratiose.g.,in the V883
those—
in IRAS 16293 —B2011).
(Jørgensen et—al.
2018) andC/
67P/C-G
Dissociative recombination of H2 D enhances the abundance Figure 8. Comparison
(⇠
89;
Mumma
Charnley
The
C
V883
OriEther
disk
seem
to be
slightlylower
thantheof COMs
reported(DrozdovskayaetDimethyl
al. 2021)
fromliterature.
The di↵erent
colorsindicate the di↵erent
molecular
species
as shown in the legend.
ratio
is
the
di↵erenceinthebindingenergies
betweenthetwothe /downsidearrows. The CHmolecular
DOH/CHV883
by
to indicate
itsof D atoms, which subsequently causes the deuteration of Upper limits are shown
CH by
OCH
CH
OCH
(25 ) OH ratio in
86± 18Ori is shown
17a semi-transparent— circleofsimpler
species
such
as
CO,
CO
,
and
2
CH2dueDOH/CHin 67P/C-G.
large uncertainty
to the large uncertainty
the spectroscopic
data of CH DOH.This might suggest the
3 OHin ratio
Glycolaldehyde
isotopologues.
Smith
et
al.
(2015)
proposedthat
theslightly
13
molecules formed on dust grain surfaces, including COMs. is supported by theCHrecent
have
also
been
measured,butnoC
fractionationha
OHCHO/CH
OH of
CHO—en- in 67P/C-G—OCS ices27— theobservationsof CH
protostellar
SO andare ubiquitously
detectedby infrared obdi↵erent
origins
OH
and
COMs
in
13
12
3
higherbindingenergy
of
CO
than
that
of
CO
(840
±
4
K
CH
OHCHO/CH
OHCHO—— (e.g., Boogert
27 et al. 2015; —velopeswhich
reportadi↵erenceinthespatialdistributions
servations
McClure et al. 2023).
In the warmer conditions (& 30 K), the fractionation is more
observed(Hässig
et
al.
2017;
Rubin
et
al.
2017)
exce
Ori
disk;
while
COMs
in
the
V883
Ori
disk
may
have
These
moleculesarealso
detected
in
the
warm
envelopesofbetween V883
nitrogenoxygen-bearing
COMs
in
protostellar† Forand12
themeasurement
in
the
V883
Ori
disk,
uncertainties
are
the
16th
and
84th
percentileoftheposterior
835
5 K on CO
ice; Smithet al. (8)
2021)
could
explainmoderate,and
since
the±backward
reactionof Equation
is notenvelopes(Csengeri
et al. 2019;
Leeetpercentile
al. 2022; (corresponding
Nazari et al. to 3 )IRAS(Drozdovskaya
et al.for2018)
and the comet
distributions.
The
0.3rd
of the16293-2422
posterior
distributions
are adopted
the trend
H
CO
(40
±
14;
Altweggetal.
2020a).
This
is
i
2
been
(re-)formedonthelukewarm
(⇠
30–50
K)
dust
grain
12
13
2023; Okoda
et al.
2021,2022).
While
thegaseousnitrogen67P/C-G(Calmonteetal.
2016).
TheSO/OCS
ratiosarelower limit of CH CHO/ CH CHO.
the high CO/
CO ratiosthethusgas canphase
ob13
severely suppressed.
Molecular
D/H inratio
be (⇠used85–165)
bearing COMs‡may
exist
in
the
inner
hot
regions
of
the
V883
⇠
0.2–0.5
in molecular
cloud ice inand COMs
in IRAS 16293-2422,
trast
to
the
observed
Cisomericfractionationin theDerived fromthefit assuming
theregion
same columnof
densityfordiskthesepairs.quiescentsurfaces
in
the
inner
the
in
its
phase,
Ori disk, theiremission may be beam-diluted and/or hidden
consistent with the value in the V883 Ori disk, suggesting
servedtowardenvironment
several low-mass
young including
stellar objects.
The⇤ Tentative measurement using tentatively detected transitions.
to probe theformationof molecules
10 by the intense
continuum
emissionas discussed
in Sec- beenthat formed
theoriginsulfur-bearingices
incoldthedi↵erence
V883(⇠
Ori 10disk haveOri
disk.
Although
the
ofthe
this
issimilar
unc
the dust
comet
67P/C-G
may
have
in

P + const.

3

13

3

3

13
3

3

12

13

3

13

12

3

3

13

13

3

3

3

3

3

13

3

100

12

N (XD)/N (XH)

12

3

13

2

3

3

3

2

3

3

3

2

10

2

3

†

1

3

10

13

13

3

13
3

3
3

13

+16 ⇤
8

3

‡

3

3

13

3

13

3

3

‡

3

13

3

⇤

+3
3
+3
2

2

3

+10 ⇤ 3
6

2

2
2

13

2

13

3

2

2

13

3

‡
‡

2

image shows several knots of 5 emission all along the ring, which are consistent with the ring emission being nearly
axisymmetric at that wavelength. The decrease in the azimuthal contrast ratio of the ring emission from 0.87 to 6.8mm can be explained by a dust-losing decaying vortex at the outer edge of a planet gap.

The Disk Orientations of Perseus Protostellar Multiples at 8 au Resolution

Nickalas K. Reynolds, John J. Tobin, Patrick D. Sheehan, Sarah I. Sadavoy, Leslie W. Looney, Kaitlin M.
Kratter, Zhi-Yun Li, Dominique M. Segura-Cox, Nathan A. Kaib F We present a statistical characterizationof circumstellar disk orientations toward 12 protostellar multiple systems in the Perseus molecular cloud using the
Atacama Large Millimeter/submillimeter Array at Band 6 (1.3 mm) with a resolution of 25 mas (8 au). This exquisite
resolution enabled us to resolve the compact inner disk structures surrounding the components of each multiple systemand to determine the projected 3-D orientation of the disks (position angle and inclination) to high precision. We
performed a statistical analysis on the relative alignment of disk pairs to determine whether the disks are preferentiallyaligned or randomly distributed. We considered three subsamples of the observations selected by the companion
separations, a <100 au, a >500 au, and a < 10,000 au. We found for the compact (< 100 au) subsample, thedistribution of orientation angles is best described by an underlying distribution of preferentially aligned sources(within 30deg) but does not rule out distributions with 40% misaligned sources. The wide companion (>500 au)
subsample appears to be consistent with a distribution of 40%-80% preferentially aligned sources. Similarly, thefull sample of systems with companions (a< 10000 au) is most consistent with a fractional ratio of at most 80%
preferentially aligned source and rules out purely randomly aligned distributions. Thus our results imply the compact
sources (<100 au) and the wide companions (>500 au) are statistically diﬀerent.

11

Ring Gap Structure around Class I Protostar WL 17

Ayumu Shoshi, Naoto Harada, Kazuki Tokuda, Yoshihiro Kawasaki, Hayao Yamasaki, Asako Sato, Mitsuki
Omura, Masayuki Yamaguchi, Kengo Tachihara, Masahiro N. Machida F WL 17 is a Class I object and wasconsidered to have a ring-hole structure. We analyzed the structure around WL 17 to investigate the detailed properties
of WL 17. We used ALMA archival data, which have a higher angular resolution than previous observations. We
investigated the WL 17 system with the 1.3 mm dust continuum and 12CO and C18O (J = 2-1) line emissions. The
dust continuum emission showed a clear ring structure with inner and outer edges of 11 and 21 au, respectively. In
addition, we detected an inner disk of < 5 au radius enclosing the central star within the ring, the first observationof this structure. Thus, WL 17 has a ring-gap structure, not a ring-hole structure. We did not detect any marked
emission in either the gap or inner disk, indicating that there is no sign of a planet, circumplanetary disk, or binary
companion. We identified the base of both blue-shifted and red-shifted outflows based on the 12CO emission, which
is clearly associated with the disk around WL 17. The outflow mass ejection rate is 3.6x10 7 Msun/yr and the
dynamical timescale is as short as 104 yr. The C18O emission showed that an inhomogeneous infalling envelope,which can induce episodic mass accretion, is distributed in the region within 1000 au from the central protostar. With
these new findings, we can constrain the planet formation and dust growth scenarios in the accretion phase of starformation.

Cluster Formation in a Filamentary Cloud: The Case of the Stellar Cluster NGC 2316

Saurabh Sharma, Aayushi Verma, Kshitiz Mallick, Lokesh K. Dewangan, Harmeen Kaur, Ram Kesh Yadav,
12which can induce episodic mass accretion, is distributed in the region within 1000 au from the central protostar. With
these new findings, we can constrain the planet formation and dust growth scenarios in the accretion phase of starformation.

Cluster Formation in a Filamentary Cloud: The Case of the Stellar Cluster NGC 2316

Saurabh Sharma, Aayushi Verma, Kshitiz Mallick, Lokesh K. Dewangan, Harmeen Kaur, Ram Kesh Yadav,
Neelam Panwar, Devendra K. Ojha, Tarak Chand, Mamta Agarwal F We present a multi-wavelength analysisof the star cluster NGC 2316 and its surroundings. We estimated the physical parameters of the NGC 2316 cluster,
including its shape (elongated), size (Rcluster = 0.4 pc), distance (1.3 +/- 0.3 kpc), and minimum reddening (AV =1.55 mag). We discovered two massive stars (B2.0V-B1.5V, age 12 Myr) embedded (AV = 4 mag) within this cluster.
The cluster region still forms young stars even though the most massive star was born 12 Myr ago. We also foundevidence of positive feedback from these massive stars. We identified a cold gas/dust lane extending westward from thecluster. The western end of the dust lane seems to favor low-mass star formation, whereas the cluster’s end favors bit
massive star formation, which seems to have started earlier than the western end. We found an elongated molecular
cloud in this region, characterized by numerous filamentary structures. The morphology of the filaments, along withposition-velocity (pv) maps, velocity dispersion maps, channel maps, etc., indicate a coalescence of filaments and apotential longitudinal flow of matter toward the cluster through the western end of the gas/dust lane. This entire
region seems to be a Hub-filamentary system (HFS), in which the NGC 2316 cluster is probably the hub and the darklane is the main filamentary structure. Being the gravity well of this HFS, star formation started first in the NGC
2316 region and went on to the other filamentary nodes.

The Role of Low-energy (< 20 eV) Secondary Electrons in the Extraterrestrial Synthesis
of Prebiotic Molecules
13lane is the main filamentary structure. Being the gravity well of this HFS, star formation started first in the NGC
2316 region and went on to the other filamentary nodes.

The Role of Low-energy (< 20 eV) Secondary Electrons in the Extraterrestrial Synthesis
of Prebiotic Molecules

Qin Tong Wu, Hannah Anderson, Aurland K. Watkins, Devyani Arora, Kennedy Barnes, Marco Padovani,
Christopher N. Shingledecker, Christopher R. Arumainayagam, James B. R. Battat F We demonstrate for the

first time that Galactic cosmic rays with energies as high as 1e10 eV can trigger a cascade of low-energy (< 20 eV)
secondary electrons that could be a significant contributor to the interstellar synthesis of prebiotic molecules whose
delivery by comets, meteorites, and interplanetary dust particles may have kick-started life on Earth. We explore therelative importance of low-energy (< 20 eV) secondary electrons–agents of radiation chemistry–and low-energy (< 10eV), non-ionizing photons–instigators of photochemistry. Our calculations indicate fluxes of 100 electrons/cm2/s for
low-energy secondary electrons produced within interstellar ices due to incident attenuated Galactic cosmic-ray (CR)
protons. Consequently, in certain star-forming regions where internal high-energy radiation sources produce ionization
rates that are observed to be a thousand times greater than the typical interstellar Galactic ionization rate, the fluxof low-energy secondary electrons should far exceed that of non-ionizing photons. Because reaction cross-sections canbe several orders of magnitude larger for electrons than for photons, even in the absence of such enhancement our
calculations indicate that secondary low-energy electrons are at least as significant as low-energy (< 10 eV) non-ionizing
photons in the interstellar synthesis of prebiotic molecules. Most importantly, our results demonstrate the pressing
need for explicitly incorporating low-energy electrons in current and future astrochemical simulations of cosmic ices.
Such models are critically important for interpreting James Webb Space Telescope infrared measurements, which are
currently being used to probe the origins of life by studying complex organic molecules found in ices near star-forming
regions.
14
13

regions.

The 3D Kinematics of the Orion Nebula Cluster II: Mass-dependent Kinematics of the
Inner Cluster

Lingfeng Wei, Christopher A. Theissen, Quinn M. Konopacky, Jessica R. Lu, Chih-Chun Hsu, Dongwon Kim

F We present the kinematic anaylsis of 246 stars within 40 from the center of Orion Nebula Cluster (ONC), the closest
massive star cluster with active star formation across the full mass range, which provides valuable insights in thethe formation and evolution of star cluster on an individual-star basis. High-precision radial velocities and surface
temperatures are retrieved from spectra acquired by the NIRSPEC instrument used with adaptive optics (NIRSPAO)
on the Keck II 10-m telescope. A three-dimensional kinematic map is then constructed by combining with the propermotions previously measured by the Hubble Space Telescope (HST) ACS/WFPC2/WFC3IR and Keck II NIRC2. The
measured root-mean-squared velocity dispersion is 2.26 ± 0.08 km s 1 , significantly higher than the virial equilibrium’s
requirement of 1.73 km s 1 , suggesting that the ONC core is supervirial, consistent with previous findings. Energy
equipartition is not detected in the cluster. Most notably, the velocity of each star relative to its neighbors is found tobe negatively correlated with stellar mass. Low-mass stars moving faster than their surrounding stars in a supervirial
cluster suggests that the initial masses of forming stars may be related to their initial kinematic states. Additionally,a clockwise rotation preference is detected. A weak sign of inverse mass segregation is also identified among stars
excluding the Trapezium stars, though it could be a sample bias. Finally, this study reports the discovery of four new
candidate spectroscopic binary systems.

Chemistry of Complex Organic Molecules in the V883 Ori Disk Revealed by ALMABand 3 Observations
15

The D/H ratios of methyl formate are slightly lower than the values in IRAS 16293-2422, possibly pointing to thedestruction and reformation of COMs in disks. We also discuss the implications for nitrogen and sulfur chemistry inprotoplanetary disks.

Insights into the first and second hydrostatic core stages from numerical simulations

Alison K. Young F The theory of how low mass stars form from the collapse of a dense molecular cloud core has

been well-established for decades. Thanks to significant progress in computing and numerical modelling, more physicalmodels have been developed and a wider parameter space explored to understand the early stages of star formation
more fully. In this review, I describe the expected physical properties of the first and second core stages and how
the inclusion of diﬀerent physics aﬀects those predicted characteristics. I provide an overview of chemical models andsynthetic observations, looking towards the positive identification of the first core in nature, which remains elusive.
However, there are a few likely candidate first cores, which are listed, and I briefly discuss the recent progress incharacterising the youngest protostellar sources. Chemistry will be instrumental in the firm identification of the firstcore so we require robust theoretical predictions of the chemical evolution of protostellar cores, especially of the firstand second core outflows. Looking ahead, simulations can shed light on how the protostellar collapse phase shapes
the evolution of the protostellar disc. Simulations of dust evolution during protostellar core collapse show there issignificant enhancement in grain size and abundance towards the centre of the core. Chemical models show that thewarm, dense conditions of the first core drive chemical evolution. There is a wide scope for further study of the rolethat the first and second core stages play in determining the structure and composition of the protostellar disc and14
envelope and, of course, the eventual influence on the formationof planets.

Surveys of clumps, cores, and condensations in Cygnus-X: SMA observations of SiO(5 4)
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Kai Yang, Keping Qiu, Xing Pan F The SiO emissions are usually used to trace high-velocity outflow shocks in star-that the first and second core stages play in determining the structure and composition of the protostellar disc andenvelope and, of course, the eventual influence on the formation of planets.

Surveys of clumps, cores, and condensations in Cygnus-X: SMA observations of SiO(5 4)
Kai Yang, Keping Qiu, Xing Pan F The SiO emissions are usually used to trace high-velocity outflow shocks in star-

forming regions. However, several studies have found low-velocity and widespread SiO emissions not associated with
outflows in molecular clouds. We aim to detect and characterize the SiO emissions in massive dense cores (MDCs), andexplore the properties of the central sources of SiO emission. We present high-angular-resolution (⇠1.500 ) observationsof the SiO (5 4) line made with the Submillimeter Array towards a sample of 48 MDCs in the Cygnus-X star-forming
complex. We studied the SiO emission structures, including their morphologies, kinematics, and energetics, andinvestigated their relationship with the evolution of the central sources. The SiO (5 4) emission is detected in 16
out of 48 MDCs. We identify 14 bipolar and 18 unipolar SiO (5 4) outflows associated with 29 dust condensations.
Most outflows (24 out of 32) are associated with excess Spitzer 4.5 µm emissions. We also find diﬀuse low-velocity( v  1.2 km s 1 ) SiO (5 4) emission closely surrounding the dust condensations in two MDCs, and suggest thatit may originate from decelerated outflow shocks or large-scale shocks from global cloud collapse. We find that the
SMA SiO (5 4) emission in MDCs is mostly associated with outflows. Probably due to the relatively high excitationof SiO (5 4) compared to SiO (2 1) and due to the spatial filtering eﬀect, we do not detect large-scale low-velocity
SiO (5 4) emission, but detect more compact low-velocity emission in close proximity to the dust condensations. We
group the sources into diﬀerent evolutionary stages based on the infrared emission, radio continuum emission, andgas temperature properties of the outflow central sources, and find that the 24 µm luminosity tends to increase withevolution.
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