星形成ゼミ 2023/11/17 #369 15-28 辰馬 (理研数理創造プログラム)
15. FAUST X: Formaldehyde in the Protobinary System [BHB2007] 11: Small Scale Deuteration
16. Evolution of Chemistry in the envelope of Hot Corinos (ECHOS). I. Extremely young sulphur chemistry
in the isolated Class 0 object B335
17. Millimetre and submillimetre spectroscopy of isobutene and its detection in the molecular cloudG+0.693
18. Millimeter emission in photoevaporating disks is determined by early substructures
19. A global view on star formation: The GLOSTAR Galactic plane survey VIII. Formaldehyde absorption in
Cygnus X
20. Protonated hydrogen cyanide as a tracer of pristine molecular gas
21. JOYS: Disentangling the warm and cold material in the high-mass IRAS 23385+6053 cluster
22. Grain Growth and Dust Segregation Revealed by Multi-wavelength Analysis of the Class I
Protostellar Disk WL 17
23. Delivery of icy planetesimals to inner planets in the Proxima Centauri planetary system
24. The Global Structure of Molecular Clouds: I. Trends with Mass and Star Formation Rate
25. The population of young low-mass stars in Trumpler 14
26. Rotational Variability and Detection of Super ares in a Young Brown Dwarf by TESS
27. SOFIA FEEDBACK Survey: The Pillars of Creation in [C II] and Molecular Linesfl

28. A resolved rotating disk wind from a young T Tauri star in the Bok globule CB26

the protostar.

Grain Growth and Dust Segregation Revealed by Multi-wavelength Analysis of theClass I Protostellar Disk WL 17

Ilseung Han, Woojin Kwon, Yusuke Aso, Jaehan Bae, Patrick Sheehan F The first step toward planet formation
is grain growth from (sub-)micrometer to millimeter/centimeter sizes. Grain growth has been reported not only in Class II
protoplanetary disks but also in Class 0/I protostellar envelopes. However, early-stage grain growth occurring in Class 0/I stages
has rarely been observed on the protostellar disk scale. Here we present the results from the ALMA Band 3 ( = 3.1 mm) and
7 ( = 0.87 mm) archival data of the Class I protostellar disk WL 17 in the ⇢ Ophiuchus molecular cloud. Disk substructures
are found in both bands, but they are diﬀerent: while a central hole and a symmetric ring appear in Band 3, an oﬀ-center holeand an asymmetric ring are shown in Band 7. Furthermore, we obtain an asymmetric spectral index map with a low meanvalue of ↵ = 2.28 ± 0.02, suggestive of grain growth and dust segregation on the protostellar disk scale. Our radiative transfer
modeling verifies these two features by demonstrating that 10 cm-sized large grains are symmetrically distributed, whereas 10µm-sized small grains are asymmetrically distributed. Also, the analysis shows that the disk is expected to be massive andgravitationally unstable. We thus suggest a single Jupiter-mass protoplanet formed by gravitational instability as the origin of
the ring-like structure, grain growth, and dust segregation identified in WL 17.

Delivery of icy planetesimals to inner planets in the Proxima Centauri planetary system

S. I. Ipatov F The estimates of the delivery of icy planetesimals from the feeding zone of Proxima Centauri c (with massequal to 7mE, mE is the mass of the Earth) to inner planets b and d were made. They included the studies of the total massof planetesimals in the feeding zone of planet c and the probabilities of collisions of such planetesimals with inner planets. This2
total mass could be about 10-15mE. It was estimated based on studies of the ratio of the mass of planetesimals ejected into

Grain Growth and Dust Segregation Revealed by Multi-wavelength Analysis of theClass I Protostellar Disk WL 17 (Han et al. 2023)
アブストラクト
目的: Class 0/Iの原始星エンベロープでのダスト成長を調べた。
方法: ρ Ophiuchus分子雲中のClass I原始星円盤WL 17の3.1, 0.87 mmのALMAアーカイブデータを解析した。
結果: 円盤のsubstructuresが、3.1 mmでは対称リングと中心の穴だが、0.87 mmでは非対称リングと中心のズレた穴であることがわかった。スペクトル指数の平均値はα = 2.28

0.02で、ダスト成長と原始星円盤スケールでのダストのサイズ分別が起きていることがわかった。
結論: 10 cmのダストが対称的に分布し、10 µmのダストは非対称に分布していると考えられる。また、円盤は重く重力的に不安定であると示唆される。すなわちWL 17のリング状構造やダスト成長、ダスト分別の起源としては、
The Astrophysical Journal, 956:9 (16pp), 2023 October 10

Han et al.

重力不安定で形成された1つの木星質量の原始惑星が考えられる。

3

Figure 2. ALMA images of WL 17. (a) Tapered Band 3 dust continuum image with the synthesized beam of 0 108 × 0 103 (PA = 67°) with the sensitivity of
34 μJy beam−1. The red plus sign indicates the position of the protostar. The original Band 3 image is shown in Figure 1. (b) Band 7 dust continuum image with thesynthesized beam of 0 107 × 0 104 (PA = 67°) with the sensitivity of 0.4 mJy beam−1. Note that substructures are different between Bands 3 and 7. (c) Spectral
index (α) map between Bands 3 and 7. The α values are overall small with a mean value of 2.28 ± 0.02, and also they are distributed asymmetrically. (d) Statisticalerror map of spectral indices. The white contours of panels (c) and (d) mark where the error level is 0.07.

the complete observed disk sample, including WL 17 (Andrews

Band 3 and κν = 3.50 cm2 g−1 in Band 7, there is a discrepancy

Grain Growth and Dust Segregation Revealed by Multi-wavelength Analysis of theClass I Protostellar Disk WL 17 (Han et al. 2023)
背景
ダストサイズは(サブ)ミリ波のダストオパシティスペクトル指数βで見積もることができる。
光学的に薄いという仮定と、Rayleigh‒Jeanʼs近似を用いると、スペクトル指数αとの関係はα = β + 2である。
The Astrophysical Journal, 956:9 (16pp), 2023 October 10(次のページで詳しく説明)

1 mm波長でβ ≤ 1.0の場合、ダストサイズは3 mmよりも大きい(Draine 2006)。
サブミクロンサイズの星間空間ダストはβ ≈ 1.7
この論文でやったこと
ALMA Band 3, 7のアーカイブデータを用いて、Class I原始星円盤WL 17を解析し、ダストサイズや分布を調べた。
WL17: M3型原始星、≤ 0.7 Myrのlate Class I原始星
円盤: Band 3の高空間分解能観測によると、
12 auの中心の穴、horseshoe-likeな狭いリング(幅11 au, 位置23 au)

4Figure 1. ALMA Band 3 (3.1 mm; 97.5 GHz) continuum image of the Class I
protostellar disk WL 17. Contour levels are {4, 8, 12, 16, 20} × σB3, whereσB3 corresponds to 33 μJy beam−1. Particularly, the noncircular 8σB3 contour
implies the weak emission in the central hole, which was previously reported in
Sheehan & Eisner (2017). The synthesized beam size shown at the lower left is
0 074 × 0 060 with PA = 74°. The red plus sign indicates the position of the
protostar.

βdex (β)dependsonvariousproperties
ofdust
grains,suchasin thenorthwest−southeast
direction
by
the
James
Clerk
pc,
which
is
the
same
as
that
used
in
Sheehan&Eisner(2017).
lawfunctionoffrequency,
κ
∝
ν
,
in
(sub)millimeterν1990).
Such
a
low
dust
opacityindexin(sub)millimeter
Maxwell
Telescope(JCMT).
The
outﬂowwasmeasuredtobeze,shape,
composition,andporosity(e.g.,
Miyake&Growthand
Dust
Segregation
Revealedby1990;Multi-wavelength
Analysis of the
Note
that
this
value
is
the
mean
distance
to
the
L1688
regioninss IGrain
wavelengths(e.g.,
Hildebrand1983;
Beckwithetal.
inclinedby 50° from the lineof sight.
wavelengths
suggeststhepossiblepresenceofmillimeter/
ththe Assuming
akagawa
1993;
Pollack
et
al.
1994;
D’Alessio
et
al.
2001;
that
thermalcontinuum
emissionoriginatesfrom
Beckwith&Sargent
1991;
Miyake&Nakagawa1993).
Basedtheρ
Ophiuchus
molecular
cloud(Ortiz-Leónetal.
2017).
The
Class
I
Protostellar
Disk
WL
17
(Han
et
al.
2023)
isothermal
dust
grainsandisoptically
thinin(sub)millimeterincentimeter-sizedlarge
grainsintheoptically
thin
disk
midplane
raine
2006;
Kataokaetal.
2014).
Among
these
dust
this wavelengths,
ondusttheoreticalstudies,
thefrequency(sub)millimeter
spectrala opacity
dust mass canmeasuredfroma total ﬂux
atabecentralof 97.5 dust
GHzopacity
is adopted
to be
operties,itishighlysensitivetothemaximum
grain
size
ta
densityasfollows(Hildebrand1983):
2−1
Miyake&Nakagawa
1993;
D’Alessio
et
al.
2001;
結果 index060)(β)
dependsonvariousproperties
ofdust
grains,
such
as
0.975
cm
g
,
which
was
calculatedfromtheequation
in
2
a
):
β

1.0
at
λ
=
1
mm
corresponds
to

3
mm
in
max
max
F
d
n
β
sner
Draine2006).
Grain
growth17
willbefurther
discussed
size,
shape,
andporosity(e.g.,
Miyake&Mdust et= composition,, inκWL(
1)
Beckwithal.
(1990):
=
10
(ν/1
THz)
and
β
=
1.
In
ν
ダスト質量::
ダスト質量吸収係数(ダストオパシティ)
Draine2006).
Thus,βiscommonlyutilizedtoinvestigate
kn Bn (Tdust )inﬁrst
Nakagawa
1993;
Pollack
et
al.
1994;
D’Alessio
et
al.
2001;
hroughtheβanalysisinthefollowing
subsection.
addition,
thiswidelyused
opacityiscomparable
totheopacityain
growthin
YSOs(e.g.,
Kwon
etal.
2009).
30
Kとすると、Band
3では26
M̲earth、Band
7では13M̲earth。
where
F
is
the
total
ﬂux
densityatthefrequency
ν,
d
is
the
s:
ν
e 1 distance,
Draine2006;
Kataokaetal.
2014).
Among
these
dust
κ
is
the
dust
mass
absorption
coefﬁcient(so-called
a
ν
with
the
maximum
grain
size
(
) the
of1を仮定)による
1 mm calculated
by
The
dust
opacity
index
(β)
is
directly
linkedtospectralmax
es
ダスト質量の違いはダストオパシティの推定(β=→質量を同じにするにはβ<1の必要があるd a dust opacity)
at the frequency
ν, and Bν(Tsensitive
properties,
itishighlytothemaximum
grainsizedust) is the Planck
dex
(α)
in
(sub)millimeter
wavelengths.
The
spectralindex
isseveralprevious
studies(see
also
Section
4.1;
e.g.,
Andrews
3.3.
SpectralIndex
1).
function
at
the
dust
temperature
T
.
The
total
ﬂux
density< at
1は、mm‒cmサイズのダストが光学的に薄い円盤赤道面に存在していることを示唆する。
dust
are → (サブ)ミリ波でβ
a
a
):
β

1.0
λ
=
1
mm
corresponds
to

3
mm
(
max
max
/
)/log(ν
/ν
),
and
are
ﬁned
as
α
=
log(
I
I
I
measured
withintheIn15σ
contourregioniswhere
6.82
mJy
B3
1
2
n
n
n
et
al.
2009,
2011;
Birnstiel
et
al.
2018;
Pavlyuchenkov
et
al.
2
1
2
ed
and (Figure→
ダストが成長している。
(Draine2006).
Thus,βiscommonlyutilizedtoinvestigate
1).
As
introducedinSection1,
thedistance
is
137
)
is
reasonably
welldescribed
asapowerA
dust
opacity(κ
eciﬁc
intensitiesatcertainfrequencies
ν
and
ν
,
respecν122019).
Regarding
dust & temperature,inmultiplepreviousheand pc, which
is
the
same
as
that
used
in
SheehanEisner(2017).
The
AstrophysicalJournal,956:9(16pp),
2023
October10β
grain
growthin
YSOs(e.g.,
Kwon
etal.
2009).
vely.
The
relationshipbetweenthespectral
index
and
the
dust
aw
functionoffrequency,
κ
∝
ν
,
in
(sub)millimeter
ダストオパシティスペクトル指数β(のβ)はダストサイズ、形状、組成、porosityに依存する。
Note
that
this
value
is
the
mean
distance
to
the
L1688
regioninνobservations
towardtheρOphiuchus
molecular
cloud,
itwaslerbe
Theis dust
opacityindex(β)
is directly
linkedto thespectraltheρOphiuchus
molecular
cloud(Ortiz-Leónetal.
2017).
The
acity
index
derivedasthefollowing
equation(e.g.,The
AstrophysicalJournal,956:9(16pp),
20
rophysicalJournal,956:9(16pp),
2023
October10→ ダスト成長を調べるために使われている。
wavelengths(e.g.,
Hildebrand1983;
Beckwith
et
al.
1990;
th
assumedtobeuniformly
20
K
for
calculating
dust
massesofling dust
opacity
at fora(α)
centralfrequencyof 97.5 GHz isthin
adoptedto2019):
be
index
in
(sub)millimeter
wavelengths.
The
spectral
index
is
the
optically
case
(τ
=
1),
assuming
theRayleigh–2015),dukagoshi
et
al.
2016;
Pavlyuchenkov
et
al.
ν
2 −1
0.975
cm
g&, Sargent
which was calculated
fromthe equation
inNakagawa 1993). Basedss
Beckwith
1991;
Miyake&/andaredeﬁned
as
α
=
log(
I
I
I
スペクトル指数:β )/log(ν1/ν2), where In
n
n
n
1
2
1
2
in
size
d
Beckwithetal.
(1990):
κ
=
10
(ν/1
THz)
and
β
=
1.
In
ν
Jeans
approximation,
Equation(2)
canbesimplyexpressed
asoptically
thin
case
(τ
=
1),
assuming
theRayleigh–2015),
dust
grainshavealreadhe theoreticalfortheoptically
thin
case
(τ
=
1),
a
4
ν
ν
h
n
k
T
on
studies,the(sub)millimeter
dust
opacityspectralB dustaddition,
this widelyused opacity
is atcomparable
to thefrequencies
opacityspeciﬁcintensities
certainνandν,
respechnet
12nphysicalJournal,956:9(16pp),
2023
October
10
millimet
he
a
=
3
+
b
,
(
2
)
a
with
the
maximum
grain
size
(
)
of
1
mm
calculated
by
in
size
duringtheprotostellar
α
=
β
+
2
(e.g.,
Kwon
etal.
2009).
On
the
other
hand,
for
the
max
pproximation,
Equation(2)
canbesimplyexpressedasJeans
approximation,
Equation(2)
cantively.
The
relationshipbetweenthespectral
index
and
the
dust
h
n
k
T
t
ndex
(β)
dependsonvariousproperties
ofdust
grains,
such
as
B
dust
n
e also Section-4.1;
1 e.g., eAndrews-1
previouskstudies
B Tdust(seeal severalopacity
demonstmillimeter/centimeter
sizes
index
is
derivedasthefollowing
equation(e.g.,
et
al.
2009,
2011;
Birnstiel
et
al.
2018;
Pavlyuchenkov
etal.
highlyoptically
thick
(τ
?1)
case
in
the
Rayleigh–Jeans+
2(e.g.,
Kwon
etal.
2009).
On
the
other
hand,
for
the
ize,
shape,
composition,andporosity(e.g.,
Miyake&ptically
thin
case
(τ
=
1),
assumingthe2015),
dust
grainshavealreadygrown
ν Rayleigh– α = β
光学的に薄い場合()、Rayleigh‒Jeans近似が使えて、となる。
+
2(e.g.,
Kwon
etal.
2009).
Onν
23 2019).
Regarding dust ettemperature,
in Pavlyuchenkov
multiple previous
Tsukagoshi
al.
2016;
et
al.
2019):
onlyafdemonstrated
by
such
a
low
β
here
h
is
the
Planckconstant,νisthegeometricmean
Nakagawa
1993;
Pollack
et
al.
1994;
D’Alessio
et
al.
2001;
光学的に厚い場合()でRayleigh‒Jeans近似の場合は、in となり、βが関係なくなる。
size
duringtheprotostellar
stages.
optically
thick
?1)
case
initiswastheRayleigh–Jeansobservations
towardthe (τ
ρ Ophiuchus
molecular
regime,(2)expressed
asas highly
α = 2,
which
means
that
roximation,
Equation(2)
canbecloud,simplyexpressed
ν Equation
optically
thick
(τ
?1)
case
ν
assumedto be uniformly
20 K for calculating
dust
massesofthe Boltzmann
equency
betweenfrequencies
ν
and
ν
,
k
is
and
CB
only
a
few
Class
I
sources,su
1
2
BDraine2006;
Kataokaetal.
2014).
Among
these
dust
→
αからβを求めるためには、光学的厚さを測定することが必要。
7.
millimeter/centimeter
sizes
on
the
h
n
k
T
(2)
expressed
as
α
=
2,
which
means
that
2Equation(e.g., Kwon
etisdustal.
2009).
Onthe
other
hand, for
the
B
dust
the
opacityindex
cannotbeestimatedfromthespectralhnet
regime,Equation(2)
isexpressedasαnnstant,
T
is
the
dust
temperature,
and
τ
is
the
geometric
dust it aν the +andCB
26
(Zhangetal.
20
a4
asymme=highly3b,(2)
properties,
issensitivetomaximumgrain
size
demonstrated
by
such
a
low
β
value,hhnkTtptically
thick
(τ
?1)
case
in
the
Rayleigh–Jeans
B indust tth opacityindex
beestimatedfromspectralnthe
ν cannotindex
at optical
Thus,
order
to
investigate
grain
growth,
it
is
kall.
T
e
1
e
1
ean
optical depth
betweendepths
and
.
Note
that
t
t
B dust5
thedust
opacityindex
cannot
be
estim
n1
n2
asymmetrically
distributed
grainsa ): β  1.0 at λ = 1 mm corresponds to a  3only
mm a few Class I sources, suchasinarE

Bands 3 and 7 are 0.707 and 10.8 m
We
adopt
a
dust
temperatureof30
Grain Growth and Dust Segregation Revealed by Multi-wavelength Analysis of the
because this value is considered the mClass I Protostellar Disk WL 17 (Han ettheal.ring2023)
based on the radiative transfer
Section 4.1. The mean optical depth va
結果
0.35
in
Band
3
and
0.57
in
Band
7,
a
The Astrophysical Journal, 956:9 (16pp), 2023 October 10
Han et al.
derived →as α = 1.84 + 0.79β. The op
プランク関数を用いた光学的厚さの計算 → 平均値がBand 3で0.35、Band 7で0.57
0.72 in Band 3 and 2.40 in Band 7. W
small α could be caused by a combin
optical depths, temperature gradients,
the line of sight (e.g., Li et al. 2017; Ga
Liu et al. 2021; Xu et al. 2023). Ho
would be limited to small regions, saffected signiﬁcantly. Therefore, withthe emissions in the two bands are m
and we will discuss it further in Sectio
et al. (2021) also showed consistent re
7 continuum emissions are marginal
entire disk region. We can thus estim
index
betweenBands
3 ofand 7
Figure 2. ALMA images of WL 17. (a) Tapered Band 3 dust continuum image with the synthesized beam of spectral
0 108 × 0 103(PA =67°) with thesensitivity
34 μJy beam−1. The red plus sign indicates the position of the protostar. The original Band 3 image is shown in Figure
1. (b) Band
7 dustcontinuum
imagewith the index
Figure
2(c)
shows
the
spectralsynthesized beam of 0 107 × 0 104 (PA = 67°) with the sensitivity of 0.4 mJy beam−1. Note that substructures are different between Bands 3 and 7. (c) SpectralBandand 7 asymmetrically.
dust continuum
imagesindex (α) map between Bands 3 and 7. The α values are overall small with a mean value of 2.28 ± 0.02, and also
they are3distributed(d) Statisticalerror map of spectral indices. The white contours of panels (c) and (d) mark where the error level is 0.07.
Only the intensity values above the低い！
6calculatethe spectral index. This spec
2 −1

protostellar
and luminosity
0.26.
Thismass
indicatesthat oftheWLvariation ofhspectral indicesand0.45–0.62
L
.
This
p
0.3
M
e
e
wavelength
range
to
the
interval
betweenBa
Usingthea wideabove
α equation,
the following
dust opacityindex
β is(e.g., Equation
power-lawfunction
(5)
from
Kwon
this
protostellar
lumino2 s2RTisochrone,whichcovers
age
S
[(
I
I
)
⎛
⎞
obsrv
model
−2/(4+β)2
obegligible,whichislarger
than
3σ.
Note
that
the
spectral
=
H
(
R
)
f
H
,
(
5
)
consistentwiththeextinction-co
Grain
Growthand
Dust
Segregation
Revealed
byMulti-wavelength
Analysis
of
the
0
(R)
=
T
(R
/
R
)
,
where
T
is
the
et
al.
2009):
T
a
and
q
are
the
maximum
grain
size
and
c
=
H
thin
sub
subreduced
subEisner (20max
as 0.56to± 0.03.
Severaltheoreticalstudieshave
Sheehan&
20 Gyr (Choi etcalculatedal. 2016). According
R0 ⎠
N
M
⎝
−
q
dust
sublimation
temperature,Risthesublimation
radiusatabsolute
ﬂux
uncertainties
does
notaffectthesub distribution
For
these
reasons,
we
assum
,
law
grain
size
n(a)
∝
a 3.1
srror
withdue
3410toK shownand0.46–0.72
Myr
have
a
and
q
withinasimilarβ proﬁlesasafunctionofClass I Protostellar Disk
WL
17
(Han
et
al.
2023)
described
inSection
max
T
=
T
,
and
β
is
the
dust
opacityindex.
Throughadetailed
dust
sub
where
f
is
the
dust-settling
factor,
H
(=1.2
au)
is
the
dust
H
0
luminosity
range
isvariation.
e. This protostellar
and0.
luminositybeM
D’Alessio
et Ianalysis,
al. and2001;
Ricci
et(2015)
2010
where
Ito
areet0.3
likewisethespeciﬁwavelength
range
to
the
interval
between
Bands
3
and
7,
where
previous
results.
The
inc
eal.
obsrv
model
radiative
transfermodeling
Kwon
al.
scale
height luminosity.
at the radius R0 (=15 au), and h (=1.275) is thenction-correctedbolometric
結果
Band
3
data
and
model,
respectively,
σ
=
g
the
above
α
equation,thedust
opacityindex
βis2018).
Accordingtothese
proﬁles,βshowed
that
the
dust
temperature
distribution
inthemidplaneobsrv
thisprotostellar
luminosity
is
a
and
q
are
the
maximum
grain
size
and
index
of
the
powerare
thus
ﬁxed
at
30°
an
B3−B7
Figure
3.
DIANA
dust
absorption
opacities
usedforradiative
transfermax
ﬂaring index.
temperaturee assume the disk
protostellar
mass Noteand that, based on the dust
−the
q 15
the
rms
noise
level
of
the
Band
3
data,
N
of
FT
Tau
disk
is
roughly
a
third
of
such
an
opticallythinamodeling.
The
adoptedopacities
and
=
1
μm
opacities
have
different
max
a
β
=
→
ダストサイズ分布がとすると、=0.2−20cm
andq=
2.5−3.0.
G
to,respectively(e.g.,
law
grain
size
distributionn(a)∝aanalysis.
ted
as
0.56
±
0.03.
Severaltheoreticalstudieshave
Sheehan&Eisner(2017).
R
max
and
0.5
L
,
respectively.
Note
that
distribution(Equation
(3)),
H
and
h
are
calculated
as
1.2
au
e
e
0
distribution,
forimagedistances
rangingfromaparticularly
q. Twograydashedverticallines
line colorstemperatureand styles dependingon pixelsontheplane,
andM
isthe
max andosity
is latethedustsame
that
adoptedin
3. DIANA
absorption
opacities
usedforradiative
transfer
D’Alessio
et
al.
2001;
Ricci
et
al.
2010b;
Birnstiel
et
al.
age
of
this
late
Class
I
protostar
(0.7
M
We
employdust
opac
andaas1.275,
respectively.
→
Class
I原始星
(≤ 0.7Myr)ですでにcmサイズまでダストが成長している。
aandq
withinasimilarβ
proﬁlesasfunctionofdescribed
inSection
3.1,
our
est
max
correspond
to
ALMA
Band
3
(3.1
mm)
and
7
(0.87
mm)
wavelengths.
For
a
few
au
to
tens
of
au
from
a
centralprotostar,
and
the
slope
of
parameters.
Finally,
Band
7
model
imagesag.
The
15
adoptedopacities
and
=
1
μm
opacities
have
different
017). Regarding
diskAccording
geometry,as these
Finally,
wesearchformodelparametersets
reproducing
the
=
0.56
corresponds2018).
toproﬁles,β(DIANA)
project(Woitkcomparison,theopacity
computedinBeckwithetal.
(1990)
isindicatedbyathe
distributionis
steeperinthemidplane.
Suchasteeperslope
B3−B7（他にそのようなClass
IはEC
53;
Lee+2020b,
CB
26;
Zhang+2021とか)
ngth
range
to
the
interval
between
Bands
3
and
7,
where
and q. Two gray dashed vertical lines
rs and styles depending on aprevious
results.
The
inclination
generated
using
the
15
best-ﬁtparameters
1,ndour
estimatesareconsistentwiththeobserved
imagesbest.
Thisprocess
includestwo
steps:
ﬁndingblack
dashed–dotted
line.
Note
that thiswidelyused
opacity
is particularly
islikelydue
toahigheroptical
depth
in
the
midplane(e.g.,to ALMA Band
3
(3.1
mm)
and
7
(0.87
mm)
wavelengths.
Fora=0.2−20cm
andq=
2.5−3.0.
Given
theestimatedtopower-lawsize
distribut
max
grain
size
distributions
andarecompared
w
d
q
are
the
maximum
grain
size
and
index
of
the
powerclination
andpositionangles
of
the
disk
are
thus
ﬁxed
at
30°
and
58°,
r
parametersets
best
ﬁtting
to
the
Band
3
image
(Figure
1),
and
a
c
=
1
cm
and
q
=
3.5.
similar
to
the
DIANA
opacitywithson, theopacity computed in Beckwith et al.
is indicated by amax
αが非対称に分布している→(1990)
ダストがサイズによって異なる分布をしている。
Looney
et
al.
2003;
Kwon
et
al.
2015).
We
apply
these
resultsa, where q weis the
p
age
offor
this
late
Class
I−
protostar(0.7
Myr; Dunham
et al. Based toq
image.
onthe
const
maxcomparison,nd58°,
respectively,
themodeling
shed–dotted
line.
Note
that
this
widelyused
opacityisparticularlycomparingthemodelimagesgeneratedusing
theparametersofto our models
because thephysical properties of both protostars,
respectively(e.g.,
ainsize
distributionn(a)∝aanalysis.
c =but
1 cm
q =73.5.
o theDIANA opacity
spatialdistributionsof
dust
grainsandidenti
輻射輸送モデル(RADMC-3D;
Dullemond+2012)
thewithﬁrsta stepat andBand
with the observational
Band
7
image
,
T
,
and
and
their
surrounding
disks
are
similar(e.g.,
L
bol
eff
sio
al. (Figure
2001;
Ricci
et
al.
2010b;
Birnstieletal.
We
employdust
opacities
com
a
grain
size,
and
is
the
maximum
grain
size.
In
order
to
cities etcomputedby the 2(b)).
DIsc
ANAlysismax
additional
substructures.
In addition, to investigate grainproperties,
Rdisk; Long etweal. 2018, 2019).6 The resultant radial dust
ダストオパシティ:
DIANA
(DIsc
ANAlysisproject;
Woitke+2016)
constrain
thesizeofdistribution
distribution
of we
dust
grains,we parameterize
ke
et
al.
2016).
The
opacities
followaa,q),covering
wide
rangestheselect
15
pairs
of
(
=
0.56
corresponds
Accordingtothese
proﬁles,β(DIANA)
project(Woitkesize, and a max−isq the maximum grain max
size.
In order totemperature
that
adopt
is deﬁned
as follows: et al.
B3−B7
a
from
=
0.05
μm
tion,
n(a)
∝
a
a
maximum
grain
size
(
)
from
10
μm
to
10
cm
and
the
a
a
and
q:
=
{10
μm,
100
μm,
1
mm,
1
cm,
10
cm},
and
min
ain
the
size
distributionofdust
grains,weparameterize
max
max
max
=
0.2−20cm
andq=
2.5−3.0.
Given
theestimated
power-lawsize
distribution,n(a0.45 4.2.
Modeling
Results
Rapower-lawindex,
istheminimum
power-lawsize
distribution
index
(q)
from
2.5
to
3.5
(see
also
nd q: a max = {10 μm,min100 μm, 1 mm, 1 cm, 10 cm},, andq = {2.5, 3.0, 3.5}. The
otherparametersforconstraining
dust
⎛
⎞
T
(
R
)
30
K
.
(3 )
=
mid
a
,
where
q
is
the
power-la
to
this
late
Class
I
protostar
(0.7
Myr;
Dunhametal.
max,propertiesq), we individually
set a to beAll
FigureFor thesefor
15 constraining
pairs of (a max
2.5, 3.0, 3.5}. The
other3).
parametersdust
au ⎠as3 thoseare assumed
thesamein the B
15
Band
modelsdeﬁned
reproduce
⎝ 15
⎜

⎟

The Astrophysical Journal, 956:9 (16pp), 2023 October 10

max

max

max

model
with
freeasparameters(Σhole
,
Σ
,
R
,
and
σ
)
ties areassumedto bethefoursame
thosedeﬁnedin
観測に合うパラメータを探した:
↑以外は
ring
ring
ring
regardlessofusedthe adopted
dust
opacities.
Figu
Woitke We
et al.
(2016).
Allthe
opacitiesforourmodelsarethat the disk
isvertically
isothermal.
Note
that
andtheﬁt opacities
to the Banddata
the imagedomain.assume
The best-ﬁt
e et al. (2016). All
used3forourinmodels
arethe Band
3 and 7with
intensityandresidual
ma
a
=
1
cm
shown inFigure3.
Particularly,
theopacity6
max
Equation(3)
iscomparable
tothemidplanetemperaturemodel is theobtained
maximizing
the likelihood function,a max = 1 cm
in Figure 3. Particularly,
opacitybywith
adoptedmodels.
The
twoleft columns
are th
and
q
=
3.5
is
comparable
tothewidelyused
onecalculatedbyby Sheehan&andEisner(2017)
andthat
used maps,
whoselogarithm
produced
RADMC-3Don
Figure3. DIANA
dust absorption
opacitieswidelyused for radiativetransfer= 3.5 is comparable
to thewidely forusedeachonemodelcalculated
by byobtainedβresidual
maps.
In
the
intensitymodeling.
The 15 adopted
opacitiesandand a β= 1=
μm opacities
have differentβBeckwithetal.
(1990):
κ
=
10
(ν/1
THz)
1.
The
ν
ith et al. (1990):(ν/1 THz)and βby= 1. Thetheκimageis deﬁned
for a ﬂared disk in radiativeequilibrium
Chiang& lines ho
andof
q. Twograydashed central
verticalline colors andstyles depending
on a (e.g.,ν = 10domain
clearlyseen,
consistingalarge
correspond to ALMABand 3 (3.1mm) and 7 (0.87 mm)
wavelengths.
For
opacityinBeckwithetal.
(1990)
is
also
supportedbythey in Beckwith et al. (1990) is also supported by theGoldreich 1997; D’Alessio
etal.the1998;
Dullemondet2001).
comparison,
opacityring
computed
in Beckwith
et al.al.
(1990)
iswhichindicated by
a c
;
3.1
au),
are
and
a
narrow(σ2
ring
1 large(Iobsrv- computed
Imodel ) opacities of
black dashed–dotted line.
Note that
this widely computed
used opacity is particularly
millimeter/centimeter-sizedlarge
grains2
es of millimeter/centimeter-sizedgrains⎡⎤We
adopt
Gaussianrings
radialdust
ln L = - S
+
ln
(
2
ps
)
,
(
6
)
a top
c surface= 1 cmand panel.
q density= 3.5.
similar forto the theDIANA
opacitywithobserved
image
in
the
left
The
resi
7
2
⎢
⎥
max

max

max

Grain Growth and Dust Segregation Revealed by Multi-wavelength Analysis of theClass I Protostellar Disk WL 17 (Han et al. 2023)
The Astrophysical Journal, 956:9 (16pp), 2023 October 10

Han et al.

モデルとの比較結果
Band 3とBand 7をよく説明できたのは、(a̲max, q) = (1 cm, 2.5), (10 cm, 2.5), (10 cm, 3.0)
特にBand 7の中心の穴の再現が難しかった。
Band 7は完璧には説明できず、ミクロンサイズのダストが非対称に分布しているのではないかと思われる。
ロスビー波不安定による渦？

8

Figure 4. Part of the 15 best-ﬁt models depending on a max and q. The top two panels are the same as the Band 3 and 7 data shown in Figures 1 and 2(b). The red star
indicates the position of the protostar. The remaining panels are the model images. From the left, the ﬁrst column shows the three Band 3 model images depending on
a max and q, the second column shows their residual maps obtained by subtracting individual models from the Band 3 observational image, the third column shows theBand 7 model images, and the fourth column shows their residual maps obtained by subtracting individual models from the Band 7 observational image. Contour
levels in the Band 3 and 7 residual maps are {−3, 3}, where σB3 = 33 μJy beam−1, and {−3, 3, 9, 15}, where σB7 = 0.4 mJy beam−1, respectively. Note that only
these three models, mainly populated by centimeter-sized large grains, reproduce well the central hole in Band 7.

vitational constant, and Σ is the disk surface density.
0.040−0.083 Me) around an M-type protostar of 0.2−0.4 Me
xpression,kistheBoltzmann
constant,
T
is
the
gas
B
Grain
GrowthDust
Revealed by Multi-wavelength Analysis of thecan fragment
and andﬁnallyform Segregation
Jupiter-mass protoplanets
re, μ(2−6is theweight,thep is theoretical
MJ) mean
within moleculara few thousand
years.and
All m
these
Class
I
Protostellar
Disk
WL
17
(Han
et
al.
2023)
ss. Weassumethat GI
gascantemperatureis theprotoplanetssame as in astudies
prove thatform Jupiter-mass
massivehence
protostellar
disk aroundandustM-typeprotostar rapidly.
perature,Tfollows
thetemperature
議論
We inspect whether WL 17 has a gravitationally unstable
n ofdisk.
the Indisk
midplane(seeEquation
(3)),
and
that
general, disk instability is determined by the Toomre Q
WL 17の円盤の構造が惑星起源である可能性が高い。
(e.g.,
Kauffmann
et al.
2008).
In addition,
the diskparameter(Toomre1964).
The Toomre
Q parameteris deﬁned
Kanagawa+2016を用いた惑星質量推定: 0.9 M̲Jnsityas Σ can be derived from the best-ﬁt radial dust
→ 重力不安定で早く形成された？
ensity distribution Σdust, whichobtained
AstrophysicalJournal,by
956:9 the(16pp), 2023 October 10
Han et al.
csThe
W is
Q
=
,
(
10
)
→
Toomre
Qを計算:
tting (Section 4.2), with a typical
pG S gas-to-dust ratio of
thatToomre
protostellar
disks around M-type protostars areQ
where cs = kB T mmp is the isothermal sound speed of annally 重力不安定条件:
unstable when Qmin 3 0.9−1.5 (e.g., Boss 2006;
ideal gas, Ω = GM R is the Keplerian angular velocity, G
Quinn
2016).
→ リングで不安定になっている。
is the gravitational constant, and Σ is the disk surface density.
7 shows Toomre Q parameter proﬁles as a function of
In the cs expression, kB is the Boltzmann constant, T is the gas
ween 8 and 24 au. These three proﬁles are obtained
temperature, μ is the mean molecular weight, and mp is the
a
=
1
cm
and
q
=
2.5,
threeproton
best-ﬁtmodels(max
mass. We assume that gas temperature is the same asa max T=follows
0 cmdust
and temperature,q = 2.5, andhence
10 cm andq=
3.0),
the dust temperaturely. TheToomreQparameter
proﬁlesdecrease
towarddistribution of the disk midplane (see Equation (3)), and thatgionμandthen(e.g.,increaseagain ettowardtheouterregion.
is 2.37
Kauffmannal.
2008).
In
addition,
theof threedisk= 1 cm and q = 2.5, (b) a= 10 cm and q = 3.0, and (c) a= 10 cm andFigure 7. Toomre Q parameter radial proﬁlesbest-ﬁt models with (a) aq = 3.0.
To focus on GI
in the ring region,Qthese proﬁles show between 8 and 24 au. In the vertical direction, the black dashed and dotted lines indicate R; 16.0 au
y, allthemodelshavethelowestToomresurface density Σ can be derived
radialdust
and σ from; 3.1 autheof the best-ﬁt
best-ﬁt models,
respectively,
and the ring region is shown as the shaded region in each panel. In the horizontal direction, the black dashed anddottedwithlines indicate
the critical
ToomreQ parameter values of 0.9 (Backus & Quinn 2016) and 1.5 (Boss 2006), respectively, for a protostellar disk around an M-typea=
1
cm
s in surface
the ring
region:themodel
density distribution Σprotostar
is grayobtaineddust, whichwith 1 M .max
Theshaded regionsby
belowthethese two lines are gravitationally unstable, meaning that Jupiter-mass planet(s) can rapidly form within the ringregion. two models with
Qminﬁtting; 0.91,and 4.2),
the withother
2.5 has
MCMC(Sectiona typical gas-to-dust ratio9 of
max

max

max

hole

ring

e

was determined to be about 3:1. The observed spectroscopic parameters for isobutene are suﬃciently accurate that calculatedtransition frequencies should be reliable up to 700 GHz. This will further help in observing this alkene in other, warmer regionsof the ISM.

Millimeter emission in photoevaporating disks is determined by early substructures

Matías Gárate, Til Birnstiel, Paola Pinilla, Sean M. Andrews, Raphael Franz, Sebastian Markus Stammler,
Giovanni Picogna, Barbara Ercolano, Anna Miotello, Nicolás T. Kurtovic F [abridged]Photoevaporation and dusttrapping are individually considered to be important mechanisms in the evolution and morphology of protoplanetary disks.
We studied how the presence of early substructures aﬀects the evolution of the dust distribution and flux in the millimeter
continuum of disks that are undergoing photoevaporative dispersal. We also tested if the predicted properties resemble thoseobserved in the population of transition disks. We used the numerical code Dustpy to simulate disk evolution considering gas
accretion, dust growth, dust-trapping at substructures, and mass loss due to X-ray and EUV (XEUV) photoevaporation and dust
entrainment. Then, we compared how the dust mass and millimeter flux evolve for diﬀerent disk models. We find that, during
photoevaporative dispersal, disks with primordial substructures retain more dust and are brighter in the millimeter continuum
than disks without early substructures, regardless of the photoevaporative cavity size. Once the photoevaporative cavity opens,
the estimated fluxes for the disk models that are initially structured are comparable to those found in the bright transition
disk population (Fmm > 30 mJy), while the disk models that are initially smooth have fluxes comparable to the transition disks
from the faint population (Fmm < 30 mJy), suggesting a link between each model and population. Our models indicate that theeﬃciency of the dust trapping determines the millimeter flux of the disk, while the gas loss due to photoevaporation controls
the formation and expansion of a cavity, decoupling the mechanisms responsible for each feature. In consequence, even a planetwith a mass comparable to Saturn could trap enough dust to reproduce the millimeter emission of a bright transition disk, while
its cavity size is independently driven by photoevaporative dispersal.

10Millimeter emission in photoevaporating disks is determined by earlysubstructures (Gárate et al. 2023)
アブストラクト
目的: 原始惑星系円盤のギャップなどのsubstructuresのありなしが、光蒸発による散逸を受けている円盤のダスト
分布やミリ波連続波のフラックスに与える影響を調べた。さらに、遷移円盤の観測との比較も行った。
方法: Dustpyを用いて、ガス降着・ダスト成長・substructuresによるダスト捕獲・X線とEUVによる光蒸発を考慮した計算を行い、円盤進化を調べた。異なる円盤モデルで、ダスト質量やミリ波フラックスの進化を比較した。
結果: 光蒸発による散逸の間、光蒸発によるcavityの大きさに関わらず、substructuresのある円盤のほうがより多くのダストを保持し、ミリ波連続波で明るくなることがわかった。光蒸発によるcavityが開くと、substructuresのある円盤のフラックスは明るい遷移円盤(F̲mm > 30 mJy)に匹敵し、なめらかな円盤のフラックスは暗い遷移円盤(F̲mm < 30 mJy)に匹敵することがわかった。
結論: ダスト捕獲の効率が円盤のミリ波フラックスを決める一方、光蒸発によるガス損失がcavity形成や成長を決め、それぞれのメカニズムは分離している。その結果、土星質量くらいの(そんなに重くないという意味)惑星ですら、明るい遷移円盤のミリ波放射を再現するダストを十分に捕獲できる。一方、cavityの大きさは光蒸発散逸により独立的に決まる。

11

be related to highly inclined disks (van der Marel et al. 2022).
y photons in the far ultra- Mixed models of photoevaporation and dead zones (Morishima
Millimeteremission in photoevaporating disks is determined by earlyV), and X-ray
wavelength
2012; Gárate et al. 2021) have also succeeded in explaining thees on the disk surface and highsubstructures(Gárateet al. 2023)
accretion rates foundin transition
disks (e.g., Cieza et al.
onal potential. When the 2012; Alcalá et al. 2014; Manara et al. 2014, 2016b,a, 2017), and背景n exceeds the local accre- the presence of a compact inner disk inside their cavities (e.g.,enters円盤寿命よりも早い円盤散逸が観測より示唆されている。
into the photoevap- Kluska et al. 2018; Pinilla et al. 2019, 2021), which was one ofar the remaining material the main limitations of models of photoevaporation acting alone.
遷移円盤を説明するものとして、光蒸発が提案されている。
de out (e.g., Clarke et al.
光蒸発とは: 高エネルギーの光子(Far UV, Extreme UV, X-ray)が円盤表面のガス粒子にぶつかり、中心星の重力ポ
Hollenbach 2009; Owen
However, in addition to the infrared deficits, wide cavities,
テンシャルから解放させる現象。
).
and high accretion rates, transition disks also seem to be dis遷移円盤のSEDの近赤外や中間赤外の欠損 → 内側領域での小さな粒子の欠乏 → 光蒸発によるcavityと一致
oposed as an explanation tributed across two populations in terms of their millimeter flux,
2of near-and
mid-infrared with a break at approximately Fmm = 30 mJy · (d/140 pc)
遷移円盤はミリ波フラックスの観点から2種類に分けられている。
the spectral energy distri- (Owen et al. 2012; Owen 2016). The fluxes of the population of
この論文でやったこと

Article number, page 1 of 17
1次元モデルを用いたダストダイナミクスの観点から、光蒸発円盤の進化を調べた。
ダスト成長・破壊(Brinstiel+2010)、X-rayとEUVの光蒸発モデル(Picogna+2019)、光蒸発風によるダスト粒子の損失(Franz+2020)
観測とも比較した。

12

ys- ture for the gas and dust volume densities ⇢g and ⇢d . Following (see Equation
4).
For
each
simulation
wetrackedtof
Picognaetal.
(2019)
used
here,
we
do
not
expectthat
their✓irr = 0.05 is the disk irradiation angle.
of whereFortheinitialgassurfacedensity
profilew
Fromang&
Nelson(2009),
andassuming
that
the
gas
is
in
verMillimeteremissioninphotoevaporatingdisks
isdetermined
by
early
M
(in
gas
and
dust),
photoevapora
g,d
2.1.
Gas
evolution
implementation
in
our
work
would
lead
to
significant
changesin
unt tical hydrostatic equilibrium (with constant temperature in the version of the Lynden-Bell & Pringle (1974)
themillimeter
continuum
F
at
1.
mm
our
conclusions.
substructures(Gárate
et
al.
2023)
tion
o- 2.2.
verticalwegoverned
model thebyverticaldensitydi↵usion
distribution
Dust
evolutionisThegas direction),
evolution
the viscousandasthethentocomparethese
properties
to
t
Fig.
1.
Example
of
the
gas
loss
rate
profile,followi
From
Equation
1
we
see
that
the
gas
evolution
canbedomiec- mass loss due to photoevaporation.
0
1
Then,
the
evolutionofthe!
1 populations.
円盤モデル
2
orationmodel
from
Picognaetal.
(2019,
their
Equa
planetarydisk
InparticForthedustevolutionmodel,
wefollowed
the
work
of
Birnstiel
B
C⌃
MatíasGárateetal.:Dustevolutioninphotoevaporative
disks
nated
by
eitherviscousdi↵usionorbyphotoevaporation.
In
the
M
r
↵
n- gas
z
B
C
g,d
disk1
0
B
C
surfacedensity⌃canbedescribed
throughthefollowing
30
gB
C
⌃
(r)
=
exp(
r/r
)
,
L
=
10
erg
s
.
The
figure
shows
the
mass
loss
rate
⇢
(z)
=
exp
,
(11)
B
C
p
g
c
x
g,d
et
al.
(2010),
which
describes
theadvection,di↵usion,
coagulathesephotoevaporating
disks
could
@
A
2 r
2
n- ガス進化:
earlystages,
when
the
disks
are
more
massive,theviscousac↵(r)
粘性拡散と光蒸発による質量損失。ギャップあり(Gaussianbump)。中心星による加熱で温度が決まる。
2⇡rdi↵usion
equation
(Lüst
1952;
Pringle
1981)
2h
c
c
2⇡h
evaporative
cavityopens(solid
line)
and
after
the
pho
g,d state (suchg,dthe self-similarinquasi-steadyassolution
describedtion,andfragmentationofmultipledust
species,
inresponsetothe transition disk millimeter fluxend cretion is generally thought !to be the dominant evolution mechity
opens(dashedline),
withthecavityedge
locatedbyLynden-Bell&
Pringle1974),
where
variations
inthe↵turtheinteraction
with
the
gas
component
throughtheaerodynamic⇣⌘
bedetected
at
all,
and
therefore
rela
@
3
@
@
where
the
dust
scale
height
h
is
where
M
=
0.05
M
is
the
total
disk
mass,
a
anism,
while
photoevaporation
will
dominatethedisk
dispersal
1/2
1/2
d proportional
diskof evolution.
after
1.9
Myr
bulence
profileyield
inversely
variations
in
the
gas
˙
⌃gforce.
=
r
⌫⌃g r
⌃w ,
(1)
drag
1
et al. 2011,
surfacefollowing⌃g! / ↵material(see examtheadisk(Owencharacteristic
radius.2012; Owen & K
d- @t
rrstages,@r density,@rapproximatelyin Thelater
removingtheremainingbyopening
corresponding
advection-di↵usion
equationforthe dust↵
ples
in
Dullemond
et
al.
2018;
Stammler
et
al.
2019;
Pinillaetal.
ng hcavity
To
introduce
a
gap
in
the
surfacedensityIn
thissectionwe
describe
the
=
h
·
min
1,
,
(12)
from
the
insideout(Clarkeetal.
2001).
d
g
2020,
among
others).
surfacedensity
⌃
is
2
d
˙
where
r
is
the
radialdistancetothecentral
star
and
⌃
is
the
ダスト進化(Brinstiel+2010):
移流、拡散、凝集、破壊。
governedbytheSmoluchowski
equation(Birnmin(St,1/2)(1+St)
beginningofthesimulation,
we
added
the
fac
w
al.
mericalgrid
setup,
theradiativetraForwith
the gastemperature
we assumed
that
the
disk
is
heatedAlongthegas removal
throughphotoevaporative
winds,!
Ina
typicalprotoplanetary
disk
there
are
two
mass
loss
rate,
which
depends
on
the
X-ray
luminosityLfromself-similarsolution.
Then,theresultinggap
stx
ct, @we canpassivelybythecentralstar,
andtherefore
its
temperature
profile@@@post-processthesimulations
and
obt
also
expectforafraction
of
the
dust
grainstobeentrained
following
Youdin&Lithwick(2007)
andBirnstieletal.
(2010),˙(rcentral⌃dis) related+ star(r
rD✏ size= R⌃,(5) is growth:to ⌃thestellartemperature
throughfragmentation
limited,or driftlimited
(see
2.3).
gas
viscousevolution
⇤ and
⇤ w,d
tent andSEDs,
sustainedbytheturbulence
profiledefi
dvd )Sectiond ⌃gTTheof theand finally our parameter sp@t@r !that the @r
@r
in
the
photoevaporativeflow(Hutchison
et
al.
2016;
Franz
et
al.
where
we
noticedust
scaleheightissmaller
than
the
gas
2012).et al. 2019; Pinilla et al. 2020; Stabythe(Stammler
1/2 kinematic viscosity ⌫, which is defined in 2010,
sk characterized
r grainsthe
used
to
study
the
impact
of
the
X-ra
1/4
one,
since
large
with
(St
&
↵)
tend
to
settletowardthe2020).
To
quantify
dust
loss
rate
we
define
a
sink
term
in
=corresponds✓irr asT ⇤to, the dust radial velocity, D is (4)Thefragmentation
limit
occurswhenthecoPringlevTd(1981)
where
the
gap
centerislocated
at
r
and
the
a
re- where
gap
the
dust
d
R⇤
erties.
midplane.
Equation5
光蒸発モデル:oflargerdust
grainssurpassthefragmentation
˙
depth
of
the
perturbationinthesurfacedensity
✏
=
⌃
/⌃
,
is
the
local
dust-to-gas
ratio,
and⌃is
ed di↵usivity,
d
g
w,d
2
1
formalexpression
forthedust-to-gas
loss
ratio
can
then
⌫ = The↵cwhere⌦,(2) old
✓
=
0.05
is
the
disk
irradiation
angle.
irrsvfragby(whichdepends
on thematerial
proper
k
mined
A
.
In
the
case
where
the
gap
amp
gap
dust
loss
rate
due
to
wind
entrainment(Hutchison
et
al.
2016;
1). the˙ w,
be⌃˙ w,dwritten= ✏w ⌃as(10)
destructive
collisions,andreplenishingthepop(i.e.,
nogap),
werecoverthetraditional
self-sim
et
al.
2020;
Hutchison&
Clarke
2021;
Booth
&
Clarkera- Franz
where 2.2.
↵ RisDust
parameter that represents the mag3.1.
Initialconditions
andnumerica
1a dimensionless3
evolution
grains(e.g.,
Ormel
&
Cuzzi
2007;
Brauer
et
al
used
a
value
of
↵
=
10
for
the
disk
base
turb
0
Franz
et
al.
2022a,b).
Here
we
note
that
Equation
5
acts
on
Fig.
1.
Example
of
the
gas
loss
rate
profile,followingthephotoevap⇢(z,a)dz
ent 2021;d
nitudeofthegas
turbulence(Shakura&
Sunyaev
1973),c=
where✏
represents
thedust-to-gas
loss
ratio,
andisdefined
in
s
h
w
w
p
orationmodel
from
Picognaet dust-to-gas
al. regime(2019, theirEquations
20and
4),
for
et
al.
2009).
Thiscanbetypically
found
For
the
dust
evolutionmodel,
wefollowed
the
work
of
BirnstielThe
initial
ratio
is
✏
=
1.5
⇥
10
R
✏
(a)
=
,
(13)
every
individual
dust
species,
and
that
all
dust
relatedquantitiesw
In
oursimulations,thecentralstarhg- our1
30
1
kB T/µm,istheisothermal
soundspeed,
withmtheproton
model
as
the
mass
fractionofparticles
that
are
small
enoughL x = 10 gions
erg s . The
figure shows the massdisks,loss rateregions
before thewith
photo-highp
et al.p(2010),
which
describes
theadvection,di↵usion,
coagula⇢(z)dz
ofprotoplanetary
g
dust
size
distribution
follows
theMRN
distribu
definedfunctionsoftheparticle
size
a.
has
en arew fragmentation of multiple dust species, in response toevaporative
cavity opens(solid line)of
and1.7after R
the photoevaporative
cava
radius,andatemperation,
mass,µ =and2.3thethegasmeanmolecular
weight,ktheBoltzmann
to coupletomotion
with
a

a
,
and
that
lie
above
the
B
w
in
pressuremaxima,
where
the
drift
velocityiszp1977),
withan
initialmaximum
grain
size
of
a
ity
opens
(dashedline),
withthecavityedge
located
at
r
⇡
30
AU
All
components
of
the
dust
dynamics
for
a
given
particle
size
cavity0
re- whichthe interaction with the gas component through the aerodynamic
match
the
stellarparametersfromt
3h,thanduetosettling
andgrowthisalwayssmaller
the
local
wind
launchingsurface
with
z
h
,
where
and
a
are
free
constant,Tthegas
temperature.
⌦
=
GM
/r
is
the
Kepleafter
1.9 Myrof dust-to-gas
evolution.
by
w
w
w
k
⇤
tial
ratio is higher than the canonic
drag force. by their dimensionless stopping time, the13 Stokes
ere are determinedof Picogna et al. (2019) and Owen &solution. Then, the resulting gap structure is consistained by theMillimeter
turbulence profile
definedininphotoevaporating
Equation 3
emissiondisks is determined by early
et al. 2019; Pinilla et al. 2020; Stadler et al. 2022),
Matías Gárate et al.:substructures(Gárate
et
al.
2023)
ap center is located at rgap and the amplitude (i.e., thee perturbationin the surface density profile)
deterMatías is
Gárateet al.: Dust evolution in photoevaporative disks
シミュレーション設定(DustPy)
protoplanetary
disks
may
heritagehigherdust-to-gas
ra
.
In
the
case
where
the
gap
amplitude
is
A
=
0
gap
gap
初期設定
the
ISM
from
the
protostellar
collapse.
Table
1.
Parameter
space.
), weprotoplanetary
recover the traditional
self-similarsolution.
We
disks may heritage higher dust-to-gas ratio than
3 M̲sun, 1.7 R̲sun, 4500 K
中心星:
0.7
For the dust grains we assumed that these are compe of the↵0 =10fromforthetheprotostellar
disk base collapse.
turbulence.
ISM
2coveredby ice, with a material
初期ダストガス比:
初期ダスト最大サイズ:
1 µm
ial dust-to-gas
ratiograinsis ✏0 =we1.5⇥ 10 ,that
and
the initial
For the dust
assumedthese
are compactands = 1.6 g cm
Variable density of ⇢
Value
1
3
a fragmentation
velocityL of
v
=
10
(Wada
et
a
coveredby ice,thewitha material
density(Mathisof ⇢ s =et1.6
andstribution
follows
MRN
distribution
al.g cm
30
1 ms
frag
コンパクトダスト、表面はice、物質密度:(silicatecore?)、破壊速度:
0.3, 1.0, 3.0
x [10 erg s ]1a計算領域:
fragmentation
velocity
of
v
=
10
m
s
(Wada
et
al.
2011;
an initialmaximum
grain
size
of
a
=
1
µm.
Our
inifrag
Gundlach
et al. 2011; Gundlach&Blum2015),thoug
0
4‒300 au、計算ダストサイズ: 0.5 µm‒20 cm
rgap [AU]20, 40, 60
et al. than2011;theGundlach& Blum2015), thoughthat
noticegas Gundlachratio
ishighercanonical
1%,
motivatedrecentresultssuggestthatthefragmentation
velocit
A
0,
1,
2,
4
gap
光蒸発風
→
1+1Dsuggest(各動径方向のグリッドで鉛直方向のグリッドを考え、ダストガス損失比を計算する)<
10 h̲gthat
recentresults
thatthefragmentation
velocityoficy
study by Lebreuilly et al. (2020), which indicates that grains could be lower than previously thought (Gundla
grains
could
be
lower
than
previously
thought(Gundlachetal.
1.3 mmでのフラックスの求め方: vertical slab近似 or 2018;
輻射輸送計算Musiolik
&
Wurm
2019;
Steinpilzetal.
2019).
2018;
Musiolik
&
Wurm
2019;
Steinpilzetal.
2019).
versionof the code
was used.
The latest version of DustPy
whicha islogarithmicallythe typical distanceof the radial
nearby gridstar-formi
verticalslab近似:自己散乱を無視している。光蒸発のcavityの端で温度構造が照射円盤とは一致しなくなる。
We
used
spaced
goin
We
used
a
logarithmicallyspacedradial
grid
going
from
on github.com/stammler/DustPy.
(Dzib
et
al.
2018;
Roccatagliataetal.
2020).
輻射輸送計算:RADMC-3D(Dullemond+2012)でダスト温度、1.3
mmフラックス、0.1µm‒1cmのSEDを計算。
4
AU
to
300
AU
with
n
=
200
radialcells,
andalogarith
4
AU
to
300
AU
with
n
=
200
radialcells,
andalogarithmically
r
r
is
built
on
the
Simframe
simulation
framework
For both the opticallythin5 and the radiative tran
12
12
5
Dust evolution
inphotoevaporative
disks
spaced
mass
grid
from
10
g
to
10
g
(approx.
0.5
µm
to
20
cm
spaced
mass
grid
from
10
g
to
10
g
(approx.
0.5µmt
opacity:
DSHARP(Birnstiel+2018):
水氷、FeS、耐火性有機物、astronomicalsilicateの組成を持つコンパクト
stammler/simframe, Stammler & Birnstiel 2022).
we used the opacity model from the DSHARP survey
ingrain
sizes)
withn=120
cells.
Finally,
in
order
to
determinemin grain sizes)
with
n
=
120
cells.
Finally,
in
order
to
de
Table
1.
Parameter
space.
ダスト粒子。OpTool(Dominik+2021)でコンパクト粒子のミー散乱を用いてopacityを求める。
mo thanet al. 2018), which assumes compact grains compose
the fraction of dust that is entrained in the photoevaporative
thewindfraction
oftroilite,
dust thatis entrained
inand
the astronomical
photoevaporati
ice,
refractoryorganics,
silic
ct and✏パラメータ
Variable
Value in which we constructed a,weemployeda
1+1D
approachw
3✏w , we employed
a 1+1D 1996;
approachwhich
we const
ning & Stognienko
Drainein2003;
Warren& Bra
andvertical grid locally
30
1
every
grid
cell
to
solve
the
integrals
L x [10 atergs ] radial
0.3, 1.0,
3.0 ←
5
x-ray
光蒸発風で損失するダストは
≤
10
µm、≥
3to
h̲g
2011;
Then
we
used
the
code
OpTool(Dominik
et
al.
2021
vertical
grid
locallyat
every
radial
grid
cell
solve
the
i
r
[AU]
20,
40,
60
gap
in function of the gas scale
noticein Equation 13.A This grid is definedtheopacities,
followingtheMietheoryforcompact
0, 1, 2, 4 ← 0はギャップなし
gap
in
Equation
13.
This
grid
is
definedinfunctionof the gof icyheight, going from the midplane to 10 hg with nz = 100 cells.
14
all
120
grain
sizes
trackedbythe
Dustpysimulations
h et al.
height, going from the midplane to 10 h with n = 100

Millimeter emission in photoevaporating disks is determined by earlysubstructures (Gárate etA&Aal.
proofs:2023)
manuscript no. aa_main_mgarate
結果

prescription of
✓ r
◆
gap
wgap = 5
AU,
40 AU

(16)

substructuresがあるとダストが残りやすい。
which roughly matches the widths of the dust traps from Pinilla
初期 ~ 200 M̲earth

et al. (2020), and is always larger than the local scale height forour parameter space.
Finally, the amount of dust removed by photoevaporation in
our model depends both on the maximum entrainment size andon the scale height of the wind launching region. As fiducial values for our simulations, we assumed that only particles smaller
than a  aw = 10 µm (Hutchison et al. 2016; Franz et al. 2020;
Hutchison & Clarke 2021; Booth & Clarke 2021) can be carriedby the photoevaporative winds, and that the particles must be atleast above z hw = 3hg , though the photoevaporative surface
can be located at higher altitudes.
In Appendix A we further explored the parameter space foraw and hw , though we do not expect for the resulting dust distribution to be greatly a↵ected by the exact parameter values,
since due to grain growth and settling dust loss should be smallin comparison to the gas loss (i.e., ✏w < ✏, Franz et al. 2022a).
Motivated by the possibility of more efficient dust removal due
to additional mechanisms such as radiation pressure (Owen &Kollmeier 2019), an FUV component in the wind (e.g., Gorti &Hollenbach 2009), or grains lifted by magneto-hydrodyamical(MHD) winds (Miyake et al. 2016), we also included a model inwhich all the dust is fully entrained in the wind (✏w = ✏). We also
included a comparison of the dust mass evolution of our fiducial
model against the entrainment prescription of Booth & Clarke(2021).

gas→ 1 Myr後に77 M̲earth (構造あり)、4 M̲earth (なし)
光蒸発によるcavityが空いたあとのダスト質量の減少は、構造のある円盤: 77→55 M̲earth
構造のない円盤: 4→3 M̲earth

cavityが開くと光蒸発によるダスト損失率は大きくなるが、

dust

gas

ダスト損失はほとんど円盤進化初期に起こっている。

4. Results
4.1. Fiducial models

In this section we present our results for the evolution of photoevaporating disks, focusing
15 on the e↵ect that early substruc-dust

Fig. 2. Top: Mass evolution of the disk mass in gas (red lines) and dust
(blue lines). Bottom: Evolution of the mass loss rate of gas and dust by
photoevaporative winds. The markers indicate the moment when photoevaporation opens a cavity in the inner disk (“+” for the initially smoothdisk, “x” for the initially structured disk).

Millimeter emission in photoevaporating disks is determined by earlysubstructures (Gárate et al. 2023)
Matías Gárate et al.: Dust evolution in photoevaporative disks

構造なし

結果

A&A proofs: manuscript

構造あり

構造なし: 光蒸発による穴の外側でダストがたまり、1つのリングになる。
構造あり: 元のリングと光蒸発によるリングの2つができ、後に1つに合体する。

構造あり

F
e
m
a
R
d
m

A&A proofs: manuscript no. aa_main_mgarate

Fig. 3. Evolution of the surface density profiles disks from t = 1 Myr,and plotted every 0.1 Myr (solid lines, with line opacity increasing withtime). The dust surface density accounts for all the grain sizes. The initial condition is shown with dashed lines.

After the photoevaporative cavity opens, the remaining dust
mass decreases from 77 M to 55 M for the structured disk
model, and from 4 M to 3 M for the smooth disk model. These
values imply that the total dust loss across the disk lifetime (orat least until the cavity size reaches rcavity = 120 AU in ourmodel) is mostly dominated by drift during the early stages of
disk evolution, rather than entrainment in the photoevaporative
winds (see also Ercolano et al. 2017).
From the surface density profiles (Figure 3) and the grain
Fig. 11. Synthetic ALMA observations at 1.3 mm of the structured disk model at 1.3size
Myr,
1.6 Myr, and
1.8 Myr,the SIMIO
distributions(Figure4 and generated5), we findusingthat oncea photoepackage (Kurtovic et al., in prep.) to post-process our radiative transfer model. The image
shows
how
our
disk
would
look
if
it
was
observedwithvaporative cavity opens, the remaining solid material is dragged
the same ALMA configuration of Elias24 (Huang et al. 2018, from the DSHARP sample),assuming
distanceof 139pcfollowing
and an inclination
29 .
along
with thea cavity
outer
edge,
the movingofpressure
The beam size is plotted in the lower-left corner. The orbit of the primordial gap (rgap =maximum.
40 AU) is For
markedwith a disk,
dashedWetonotethat this isof athe smooththisline.
leads
the formation
not intended to be a comparison “with” Elias24.
single dust trap at 1.4 Myr, that moves outward as time passes.
For the structured disk, on the other hand, we find that between
1.2 and 1.4 Myr there are two traps present, one that follows the

16

F
w
r
d
s

Fig. 4. Dust size distribution for a smooth disk at 1.2, 1.6, and 2.1 Myr.
The drift (cyan) and fragmentation (pink) growth limits are also indicated.

Fig. 5. Dust size distribution for a structured disk at 1.1, 1.3, and
1.6 Myr. The drift (cyan) and fragmentation (pink) growth limits arealso indicated. The last two snapshots were selected to match the onesof Figure 4 in terms of the photoevaporative cavity size.

t
u
F
i
r
a
t

Millimeter emission in photoevaporating disks is determined by earlysubstructures (Gárate et al. 2023)
結果

cript no. aa_main_mgarate

ミリ波フラックス

Matías Gárate et al.: Dust evolutio構造のあり/なしはSEDには影響をあまり与えない。
X-ray光度の影響:

構造あり

光度が高いと光蒸発cavityが開くのが早い。
構造あり→ 構造なしの場合、構造なし

cavityが開いたときのダスト質量と構造なし

構造あり

ミリ波フラックスがより高くなる。
→ 構造ありの場合、

Fig. 6. Millimeter fluxes Fmm , as a function of the size of the photoevaporative cavity for the smooth (dotted) and structured (solid) disk
models. The solid and dotted lines represent flux from the optically thinapproximation (Equation 15). The markers are the fluxes obtained with
RADMC-3D (“+” for the smooth disk, “x” for the structured disk). The
disks are assumed to be at 140 pc, and no inclination. The cavity size
measurement is based on the dust distribution of millimeter sized grains.

構造なし

X-ray光度にあまり依存しない。
Fig. 8. Evolution of the dust mass (top) and disk flux at = 1.3 mm(bottom, assuming a distance of 140 pc), for di↵erent X-ray luminosities
L x , with the black line corresponding to the fiducial value. The markers
indicate the moment when photoevaporation opens a cavity in the innerdisk (“+” for the smooth disk, “x” for the structured disk).

17

Fi
pl
Lx

m
(a

gh it is an open mass, µ = 2.3 the mean molecular weight, kB the Boltzmannpd be able to reconstant, T the gas temperature. ⌦k = GM⇤ /r3 , is the Kepley dust traps wereMillimeter emission in photoevaporating disks is determined by earlyrian orbital speed, with G the gravitational constant, and M⇤ thefraction of relicmass of the central star. substructures (Gárate et al. 2023)
d (see Ercolano
To induce a gap-like substructure in the gas surface density,
such as the one that would be created by a planet, we implephotoevaporat結果
mented the following radial turbulence profile that includes a
dynamics, using Gaussian bumpthe presenceof
構造ありの場合のギャップ深さ依存性
ギャップ位置r̲gapは結果にあまり影響を与えない。
0
0 ⇣
11
⌘
2
planets) a↵ects
B
B
C
C
B
B
C
CCC
r
r
gap
B
B
C
乱流強度:
B
B
C
CCCCCC ,during photoe- ↵(r) = ↵0 ⇥ BBB1 + Agap exp BBB
オパシティモデルを変えても傾向は変わらない。
(3)
B
B
C
C
2
ution in photoevaporative disks@@
2wgap AA
flux in the milthe infrared. In
ntation of multi- where ↵0 is the base value for the turbulence, rgap is the location
Gaussianstandard deviation thatf-the-art models of the gap structure, wA̲gap
gap is the =2
et al. 2019), and controls the gap width, and Agap is the amplitude of the bump,
土星質量相当depth of the gap in the gas surface
ve winds (Franz which in turn controls→thedensity profile. This Gaussian factor was also used by PinillaA̲gap= 1,it 2のtheir study
was used to create bumps
bservational sig- et al. (2020), though ininstead of gaps.
ed to those ob- in the surface density, 間に境界
Physically, a local increment in the kinematic viscosity creer flux and moructures and their ates a region where the gas di↵uses faster, which translates intoa gap in the surface density profile. For disks that are in steadyresent in the disk state, the gas accretion rate is radially constant, and given by
early” or “primor- Ṁg = 3⇡⌃g ⌫ (Pringle 1981). The relation between the gas surface density and viscosity can also be applied to disks that are

Fig. 9. Same as Figure 8, but for structured disks with di↵erent gap amplitudes, with a fixed location at rgap = 40 AU and X-ray luminosity of
L x = 1030 erg s 1 . Notice that the axis scales are di↵erent from Figure 8.

18

Millimeter emission in photoevaporating disks is determined by earlysubstructures (Gárate et al. 2023)
議論
光蒸発: ガストダストに深いcavityを作る。深いcavityには惑星の存在は関係ない。
早期のsubstructuresの有無: 円盤のミリ波フラックスを決める。明るい遷移円盤は土星質量の惑星で説明できる。
遷移円盤の比較的高い降着率: 内側領域にデッドゾーンがあれば、内側円盤が長期に渡って残り、光蒸発でcativyが開いたとしても高い降着率を説明できる。
substructuresと光蒸発cavityが両方ある場合の進化: 2つのリングが1つに合体する。合体したあとは光蒸発でリンA&A proofs: manuscript no. aa_main_mgarate
グ位置が決まるので、substructuresを作っていた惑星に関する情報をリングから得ることはできなくなる。

Fig. 11. Synthetic ALMA observations at 1.3 mm of the structured disk model at 1.3 Myr, 1.6 Myr, and 1.8 Myr, generated using the SIMIO
package (Kurtovic et al., in prep.) to post-process our radiative transfer model. The image shows how our disk would look if it was observed withthe same ALMA configuration of Elias24 (Huang et al. 2018, from the DSHARP sample), assuming a distance of 139 pc and an inclination of 29 .
The beam size is plotted in the lower-left corner. The orbit of the primordial gap (rgap = 40 AU) is marked with a dashed line. We note that this is
not intended to be a comparison “with” Elias24.

19 of planet candidates within transition disk cavities. Our model

early stage) because the photoevaporative cavity was only able

water-poor dust in the coma. Lifted dust can be heated, fragmented, and super-heated; whereby, ammonium salts, if present,
can rapidly thermally disintegrate and modify the NH3 /H2 O ratio.

FAUST X: Formaldehyde in the Protobinary System [BHB2007] 11: Small Scale Deuteration

Lucy Evans, Charlotte Vastel, Francisco Fontani, Jaime Pineda, Izaskun Jiménez-Serra, Felipe Alves, Takeshi
Sakai, Mathilde Bouvier, Paola Caselli, Cecilia Ceccarelli, Claire Chandler, Brian Svoboda, Luke Maud, Claudio Codella, Nami Sakai, Romane Le Gal, Ana López-Sepulcre, George Moellenbrock, Satoshi Yamamoto F
Context. Deuterium in H-bearing species is enhanced during the early stages of star formation, however, only a small number ofhigh spatial resolution deuteration studies exist towards protostellar objects, leaving the small-scale structures unrevealed andunderstudied. Aims. We aim to constrain the deuterium fractionation ratios in a Class 0/I protostellar object in formaldehyde(H2CO), which has abundant deuterated isotopologues in this environment. Methods. We observed the Class 0/I protobinary
system [BHB2007] 11, whose emission components are embedded in circumstellar disks that have radii of 2-3 au, using ALMA
within the context of the Large Program FAUST. The system is surrounded by a complex filamentary structure connecting to
the larger circumbinary disk. In this work we present the first study of formaldehyde D-fractionation towards this source with
detections of H2CO 3(0,3)-2(0,2), combined with HDCO 4(2,2)-3(2,1), HDCO 4(1,4)-3(1,3) and D2CO 4(0,4)-3(0,3). Theseobservations enable multiple velocity components associated with the methanol hotspots also uncovered by FAUST data, as
well as the external envelope, to be resolved. In addition, based on the kinematics seen in the observations of the H2CO
emission, we propose the presence of a second large scale outflow. Results. HDCO and D2CO are only found in the central
regions of the core while H2CO is found more ubiquitously. From radiative transfer modelling, the column densities ranges
found for H2CO, HDCO and D2CO are (3-8)x1014 cm 2 , (0.8-2.9)x1013 cm 2 and (2.6-4.3)x1012 cm 2 , respectively, yielding
an average D/H ratio of 0.01-0.04. Following the results of kinematic modelling, the second large scale feature is inconsistent
with a streamer-like nature and we thus tentatively conclude that the feature is an asymmetric molecular outflow launched bya wide-angle disk wind.
20

Evolution of Chemistry in the envelope of Hot Corinos (ECHOS). I. Extremely young
sulphur chemistry in the isolated Class 0 object B335

G. Esplugues, M. Rodríguez-Baras, D. San Andrés, D. Navarro-Almaida, A. Fuente, P. Rivière-Marichalar, Á.
Sánchez-Monge, M. N. Drozdovskaya, S. Spezzano, P. Caselli F Within the project Evolution of Chemistry in theenvelope of HOt corinoS (ECHOS), we present a study of sulphur chemistry in the envelope of the Class 0 source B335 throughobservations in the spectral range 7, 3, and 2 mm. We have modelled observations assuming LTE and LVG approximation. We
have also used the code Nautilus to study the time evolution of sulphur species. We have detected 20 sulphur species with a
total gas-phase S abundance similar to that found in the envelopes of other Class 0 objects, but with significant diﬀerences in
the abundances between sulphur carbon chains and sulphur molecules containing oxygen and nitrogen. Our results highlightthe nature of B335 as a source especially rich in sulphur carbon chains unlike other Class 0 sources. The low presence or absenceof some molecules, such as SO and SO+, suggests a chemistry not particularly influenced by shocks. We, however, detect alarge presence of HCS+ that, together with the low rotational temperatures obtained for all the S species (<15 K), reveals
the moderate or low density of the envelope of B335. We also find that observations are better reproduced by models with asulphur depletion factor of 10 with respect to the sulphur cosmic elemental abundance. The comparison between our model
45
and observational results for B335 reveals an age of 10 <t<10 yr, which highlights the particularly early evolutionary stageof this source. B335 presents a diﬀerent chemistry compared to other young protostars that have formed in dense molecular
clouds, which could be the result of accretion of surrounding material from the diﬀuse cloud onto the protostellar envelope of
B335. In addition, the analysis of the SO2/C2S, SO/CS, and HCS+/CS ratios within a sample of prestellar cores and Class 0
objects show that they could be used as good chemical evolutionary indicators of the prestellar to protostellar transition.

Millimetre and submillimetre spectroscopy of isobutene and its detection in the molecular cloud G+0.693
21

and observational results for B335 reveals an age of 104 <t<105 yr, which highlights the particularly early evolutionary stageof this source. B335 presents a diﬀerent chemistry compared to other young protostars that have formed in dense molecular
clouds, which could be the result of accretion of surrounding material from the diﬀuse cloud onto the protostellar envelope of
B335. In addition, the analysis of the SO2/C2S, SO/CS, and HCS+/CS ratios within a sample of prestellar cores and Class 0
objects show that they could be used as good chemical evolutionary indicators of the prestellar to protostellar transition.

Millimetre and submillimetre spectroscopy of isobutene and its detection in the molecular cloud G+0.693

Mariyam Fatima, Holger S. P. Müller, Oliver Zingsheim, Frank Lewen, Víctor M. Rivilla, Izaskun JiménezSerra, Jesús Martín-Pintado, Stephan Schlemmer F Isobutene ((CH3 )2 C=CH2 ) is one of the four isomers of butene(C4 H8 ). Given the detection of propene (CH3 CH=CH2 ) toward TMC-1, and also in the warmer environment of the solar-type
protostellar system IRAS 16293 2422, one of the next alkenes, isobutene, is a promising candidate to be searched for in space.
We aim to extend the limited line lists of the main isotopologue of isobutene from the microwave to the millimetre region inorder to obtain a highly precise set of rest frequencies and to facilitate its detection in the interstellar medium. We investigated the rotational spectrum of isobutene in the 35 370 GHz range using absorption spectroscopy at room temperature.
Quantum-chemical calculations were carried out to evaluate vibrational frequencies. We determined new or improved spectroscopic parameters for isobutene up to a sixth-order distortion constant. These new results enabled its detection in the G+0.693
molecular cloud for the first time, where propene was also recently found. The propene to isobutene column density ratio
was determined to be about 3:1. The observed spectroscopic parameters for isobutene are suﬃciently accurate that calculatedtransition frequencies should be reliable up to 700 GHz. This will further help in observing this alkene in other, warmer regionsof the ISM.

Millimeter emission in photoevaporating disks is determined by early substructures

Matías Gárate, Til Birnstiel, Paola Pinilla, Sean M. Andrews, Raphael Franz, Sebastian Markus Stammler,
Giovanni Picogna, Barbara Ercolano, Anna Miotello, Nicolás T. Kurtovic F [abridged]Photoevaporation and dusttrapping are individually considered to be important mechanisms
in the evolution and morphology of protoplanetary disks.
22A global view on star formation: The GLOSTAR Galactic plane survey VIII. Formaldehyde absorption in Cygnus X

Y. Gong, G. N. Ortiz-León, M. R. Rugel, K. M. Menten, A. Brunthaler, F. Wyrowski, C. Henkel, H. Beuther,S. A. Dzib, J. S. Urquhart, A. Y. Yang, J. D. Pandian, R. Dokara, V. S. Veena, H. Nguyen, S. -N. X. Medina,W. D. Cotton, W. Reich, B. Winkel, P. Müller, I. Skretas, T. Csengeri, S. Khan, A. Cheema F Cygnus X is oneof the closest and most active high-mass star-forming regions in our Galaxy, making it one of the best laboratories for studying
massive star formation. As part of the GLOSTAR Galactic plane survey, we performed large scale simultaneous H2 CO (11,0 11,1 ) spectral line and radio continuum imaging observations toward Cygnus X at ⇠6 cm with the Karl G. Jansky Very Large
Array and the Eﬀelsberg-100 m radio telescope. Our Eﬀelsberg observations reveal widespread H2 CO (11,0 -11,1 ) absorption
with a spatial extent of &50 pc in Cygnus X for the first time. On large scales of 4.4 pc, the relative orientation between local
222
velocity gradient and magnetic field tends to be more parallel at H2 column densities of &1.8⇥10 cm . On the smaller scaleof 0.17 pc, our VLA+Eﬀelsberg combined data reveal H2 CO absorption only toward three bright HII regions. Our observations
demonstrate that H2 CO (11,0 -11,1 ) is commonly optically thin. Kinematic analysis supports the assertion that molecular clouds
generally exhibit supersonic motions on scales of 0.17-4.4 pc. We show a non-negligible contribution of the cosmic microwave
background radiation in producing extended absorption features in Cygnus X. Our observations suggest that H2 CO (11,0 11,1 )21
2
can trace molecular gas with H2 column densities of & 5 ⇥ 10 cm . The ortho-H2 CO fractional abundance with respect toH2 has a mean value of 7.0⇥10 10 . A comparison of velocity dispersions on diﬀerent linear scales suggests that the dominant
3 km s 1 velocity component in the prominent DR21 region has nearly identical velocity dispersions on scales of 0.17-4.4 pc,
which deviates from the expected behavior of classic turbulence.

Protonated hydrogen cyanide as a tracer of pristine molecular gas

Y. Gong, F. J. Du, C. Henkel, A. M. Jacob, A. Belloche,
J. Z. Wang, K. M. Menten, W. Yang, D. H. Quan,
23

H2 has a mean value of 7.0⇥10. A comparison of velocity dispersions on diﬀerent linear scales suggests that the dominant
1
3 km s velocity component in the prominent DR21 region has nearly identical velocity dispersions on scales of 0.17-4.4 pc,
which deviates from the expected behavior of classic turbulence.
10

Protonated hydrogen cyanide as a tracer of pristine molecular gas

Y. Gong, F. J. Du, C. Henkel, A. M. Jacob, A. Belloche, J. Z. Wang, K. M. Menten, W. Yang, D. H. Quan,+
C. T. Bop, G. N. Ortiz-León, X. D. Tang, M. R. Rugel, S. Liu F Protonated hydrogen cyanide, HCNH , plays afundamental role in astrochemistry because it is an intermediary in gas-phase ion-neutral reactions within cold molecular clouds.
+
However, the impact of the environment on the chemistry of HCNH remains poorly understood. With the IRAM-30 m and+
APEX-12 m observations, we report the first robust distribution of HCNH in the Serpens filament and in Serpens South. Our+data suggest that HCNH is abundant in cold and quiescent regions, but is deficit in active star-forming regions. The observed
HCNH+ fractional abundances relative to H2 range from 3.1 ⇥ 10 11 in protostellar cores to 5.9 ⇥ 10 10 in prestellar cores,
and the HCNH+ abundance generally decreases with increasing H2 column density, which suggests that HCNH+ coevolves withcloud cores. Our observations and modeling results suggest that the abundance of HCNH+ in cold molecular clouds is strongly
dependent on the H2 number density. The decrease in the abundance of HCNH+ is caused by the fact that its main precursors(e.g., HCN and HNC) undergo freeze-out as the number density of H2 increases. However, current chemical models cannot
explain other observed trends, such as the fact that the abundance of HCNH+ shows an anti-correlation with that of HCN and+
HNC, but a positive correlation with that of N2 H in the southern part of the Serpens South northern clump. This indicates+that additional chemical pathways have to be invoked for the formation of HCNH via molecules like N2 in regions in which+
HCN and HNC freeze out. Both the fact that HCNH is most abundant in molecular cores prior to gravitational collapse and+the fact that low-J HCNH transitions have very low H2 critical densities make this molecular ion an excellent probe of pristine
molecular gas.

JOYS: Disentangling the warm and cold material in the high-mass IRAS 23385+6053
cluster24

C. Gieser, H. Beuther, E. F. van Dishoeck, L. Francis, M. L. van Gelder, L. Tychoniec, P. J. Kavanagh,

HCN and HNC freeze out. Both the fact that HCNH is most abundant in molecular cores prior to gravitational collapse and+the fact that low-J HCNH transitions have very low H2 critical densities make this molecular ion an excellent probe of pristine
molecular gas.
+

JOYS: Disentangling the warm and cold material in the high-mass IRAS 23385+6053
cluster
C. Gieser, H. Beuther, E. F. van Dishoeck, L. Francis, M. L. van Gelder, L. Tychoniec, P. J. Kavanagh,
G. Perotti, A. Caratti o Garatti, T. P. Ray, P. Klaassen, K. Justtanont, H. Linnartz, W. R. M. Rocha, K.
Slavicinska, L. Colina, M. Güdel, Th. Henning, P. -O. Lagage, G. Östlin, B. Vandenbussche, C. Waelkens,
G. Wright F (abridged) We study and compare the warm (>100 K) and cold (<100 K) material toward the high-mass starforming region IRAS 23385+6053 (IRAS 23385 hereafter) combining high angular resolution observations in the mid-infrared(MIR) with the JWST Observations of Young protoStars (JOYS) project and with the NOEMA at mm wavelengths at angularresolutions of 0.2"-1". The spatial morphology of atomic and molecular species is investigated by line integrated intensity maps.
The temperature and column density of diﬀerent gas components is estimated using H2 transitions (warm and hot component)
and a series of CH3CN transitions as well as 3 mm continuum emission (cold component). Toward the central dense core in
IRAS 23385 the material consists of relatively cold gas and dust ( 50 K), while multiple outflows create heated and/or shocked
H2 and show enhanced temperatures ( 400 K) along the outflow structures. An energetic outflow with enhanced emission knotsof [Fe II] and [Ni II] hints at J-type shocks, while two other outflows have enhanced emission of only H2 and [S I] caused by
C-type shocks. The latter two outflows are also more prominent in molecular line emission at mm wavelengths (e.g., SiO, SO,
H2CO, and CH3OH). Even higher angular resolution data are needed to unambiguously identify the outflow driving sources
given the clustered nature of IRAS 23385. While most of the forbidden fine structure transitions are blueshifted, [Ne II] and[Ne III] peak at the source velocity toward the MIR source A/mmA2 suggesting that the emission is originating from closer to825and an asymmetric ring are shown in Band 7. Furthermore, we obtain an asymmetric spectral index map with a low meanvalue of ↵ = 2.28 ± 0.02, suggestive of grain growth and dust segregation on the protostellar disk scale. Our radiative transfer
modeling verifies these two features by demonstrating that 10 cm-sized large grains are symmetrically distributed, whereas 10µm-sized small grains are asymmetrically distributed. Also, the analysis shows that the disk is expected to be massive andgravitationally unstable. We thus suggest a single Jupiter-mass protoplanet formed by gravitational instability as the origin of
the ring-like structure, grain growth, and dust segregation identified in WL 17.

Delivery of icy planetesimals to inner planets in the Proxima Centauri planetary system

S. I. Ipatov F The estimates of the delivery of icy planetesimals from the feeding zone of Proxima Centauri c (with massequal to 7mE, mE is the mass of the Earth) to inner planets b and d were made. They included the studies of the total massof planetesimals in the feeding zone of planet c and the probabilities of collisions of such planetesimals with inner planets. This
total mass could be about 10-15mE. It was estimated based on studies of the ratio of the mass of planetesimals ejected into
hyperbolic orbits to the mass of planetesimals collided with forming planet c. At integration of the motion of planetesimals,
the gravitational influence of planets c and b and the star was taken into account. In most series of calculations, planetesimals
collided with planets were excluded from integrations. Based on estimates of the mass of planetesimals ejected into hyperbolic
orbits, it was concluded that during the growth of the mass of planet c the semi-major axis of its orbit could decrease by atleast a factor of 1.5. Depending on possible gravitational scattering due to mutual encounters of planetesimals, the total massof material delivered by planetesimals from the feeding zone of planet c to planet b was estimated to be between 0.002mE and0.015mE. Probably, the amount of water delivered to Proxima Centauri b exceeded the mass of water in Earth’s oceans. The
amount of material delivered to planet d could be a little less than that delivered to planet b.

The Global Structure of Molecular Clouds: I. Trends with Mass and Star Formation
Rate

Nia Imara, John C. Forbes F We introduce a model for the large-scale, global 3D structure of molecular clouds. Motivatedby the morphological appearance of clouds in surface density maps, we model clouds as cylinders, with the aim of backing out
information about the volume density distribution of gas and its
26 relationship to star formation. We test our model by applying

the gravitational influence of planets c and b and the star was taken into account. In most series of calculations, planetesimals
collided with planets were excluded from integrations. Based on estimates of the mass of planetesimals ejected into hyperbolic
orbits, it was concluded that during the growth of the mass of planet c the semi-major axis of its orbit could decrease by atleast a factor of 1.5. Depending on possible gravitational scattering due to mutual encounters of planetesimals, the total massof material delivered by planetesimals from the feeding zone of planet c to planet b was estimated to be between 0.002mE and0.015mE. Probably, the amount of water delivered to Proxima Centauri b exceeded the mass of water in Earth’s oceans. The
amount of material delivered to planet d could be a little less than that delivered to planet b.

The Global Structure of Molecular Clouds: I. Trends with Mass and Star Formation
Rate

Nia Imara, John C. Forbes F We introduce a model for the large-scale, global 3D structure of molecular clouds. Motivatedby the morphological appearance of clouds in surface density maps, we model clouds as cylinders, with the aim of backing out
information about the volume density distribution of gas and its relationship to star formation. We test our model by applying
it to surface density maps for a sample of nearby clouds and find solutions that fit each of the observed radial surface density
profiles remarkably well. Our most salient findings are that clouds with higher central volume densities are more compact andalso have lower total mass. These same lower-mass clouds tend to have shorter gas depletion times, regardless of whether weconsider their total mass or dense mass. Our analyses lead us to conclude that cylindrical clouds can be characterized by auniversal structure that sets the timescale on which they form stars.

The population of young low-mass stars in Trumpler 14

Dominika Itrich, Leonardo Testi, Giacomo Beccari, Carlo F. Manara, Megan Reiter, Thomas Preibisch, Anna
F. McLeod, Giovanni Rosotti, Ralf Klessen, Sergio Molinari, Patrick Hennebelle F Massive star-forming regions
are thought to be the most common birth environments in the Galaxy and the only birth places of very massive stars. Their
presence in the stellar cluster alters the conditions within the cluster impacting at the same time the evolution of other cluster
members. In principle, copious amounts of ultraviolet radiation produced by massive stars can remove material from outer parts27

it to surface density maps for a sample of nearby clouds and find solutions that fit each of the observed radial surface density
profiles remarkably well. Our most salient findings are that clouds with higher central volume densities are more compact andalso have lower total mass. These same lower-mass clouds tend to have shorter gas depletion times, regardless of whether weconsider their total mass or dense mass. Our analyses lead us to conclude that cylindrical clouds can be characterized by auniversal structure that sets the timescale on which they form stars.

The population of young low-mass stars in Trumpler 14

Dominika Itrich, Leonardo Testi, Giacomo Beccari, Carlo F. Manara, Megan Reiter, Thomas Preibisch, Anna
F. McLeod, Giovanni Rosotti, Ralf Klessen, Sergio Molinari, Patrick Hennebelle F Massive star-forming regions
are thought to be the most common birth environments in the Galaxy and the only birth places of very massive stars. Their
presence in the stellar cluster alters the conditions within the cluster impacting at the same time the evolution of other cluster
members. In principle, copious amounts of ultraviolet radiation produced by massive stars can remove material from outer partsof the protoplanetary disks around low- and intermediate-mass stars in the process of external photoevaporation, eﬀectively
reducing the planet-formation capabilities of those disks. Here, we present deep VLT/MUSE observations of low-mass stars in
Trumpler 14, one of the most massive, young, and compact clusters in the Carina Nebula Complex. We provide spectral andstellar properties of 717 sources and based on the distribution of stellar ages derive the cluster age of ⇠1 Myr. The majority ofthe stars in our sample have masses 61 M , what makes our spectroscopic catalogue the most deep to date in term of masses,
and proves that detailed investigations of low-mass stars are possible in the massive but distant regions. Spectroscopic studiesof low-mass members of the whole Carina Nebula Complex are missing. Our work provides an important step forward towards
filling this gap and set the stage for follow-up investigation of accretion properties in Trumpler 14.

928

Rotational Variability and Detection of Superflares in a Young Brown Dwarf by TESS

Rajib Kumbhakar, Soumen Mondal, Samrat Ghosh, Diya Ram, Sudip Pramanik F We present a comprehensive
analysis of a Transiting Exoplanet Survey Satellite (TESS) high-quality light curve for a young brown dwarf, MHO 4 having
spectral type M7.0, in the Taurus star-forming region. We investigate the rotation periods and characterize the BD’s dynamic
atmosphere and surface features. We present light curve analysis of MHO 4, and estimate the rotation period to be around2.224 d. Remarkably, MHO 4 exhibits two significant flaring events. Furthermore, we also estimated bolometric flare energies
34
35
to be within the energy range of 10 to 10 erg, which sits in the superflare category.

SOFIA FEEDBACK Survey: The Pillars of Creation in [C II] and Molecular Lines

Ramsey L. Karim, Marc W. Pound, Alexander G. G. M. Tielens, Maitraiyee Tiwari, Lars Bonne, Mark G.
Wolfire, Nicola Schneider, Ümit Kavak, Lee G. Mundy, Robert Simon, Rolf Güsten, Jürgen Stutzki, Friedrich
Wyrowski, Netty Honingh F We investigate the physical structure and conditions of photodissociation regions (PDRs) andmolecular gas within the Pillars of Creation in the Eagle Nebula using SOFIA FEEDBACK observations of the [C II] 158 micron1
line. These observations are velocity resolved to 0.5 km s and are analyzed alongside a collection of complimentary data withsimilar spatial and spectral resolution: the [O I] 63 micron line, also observed with SOFIA, and rotational lines of CO, HCN,
HCO+ , CS, and N2 H+ . Using the superb spectral resolution of SOFIA,
APEX, CARMA, and BIMA, we reveal the relationships
29spectral type M7.0, in the Taurus star-forming region. We investigate the rotation periods and characterize the BD’s dynamic
atmosphere and surface features. We present light curve analysis of MHO 4, and estimate the rotation period to be around2.224 d. Remarkably, MHO 4 exhibits two significant flaring events. Furthermore, we also estimated bolometric flare energies
34
35
to be within the energy range of 10 to 10 erg, which sits in the superflare category.

SOFIA FEEDBACK Survey: The Pillars of Creation in [C II] and Molecular Lines

Ramsey L. Karim, Marc W. Pound, Alexander G. G. M. Tielens, Maitraiyee Tiwari, Lars Bonne, Mark G.
Wolfire, Nicola Schneider, Ümit Kavak, Lee G. Mundy, Robert Simon, Rolf Güsten, Jürgen Stutzki, Friedrich
Wyrowski, Netty Honingh F We investigate the physical structure and conditions of photodissociation regions (PDRs) andmolecular gas within the Pillars of Creation in the Eagle Nebula using SOFIA FEEDBACK observations of the [C II] 158 micronline. These observations are velocity resolved to 0.5 km s 1 and are analyzed alongside a collection of complimentary data withsimilar spatial and spectral resolution: the [O I] 63 micron line, also observed with SOFIA, and rotational lines of CO, HCN,
HCO+ , CS, and N2 H+ . Using the superb spectral resolution of SOFIA, APEX, CARMA, and BIMA, we reveal the relationships
between the warm PDR and cool molecular gas layers in context of the Pillars’ kinematic structure. We assemble a geometricpicture of the Pillars and their surroundings informed by illumination patterns and kinematic relationships and derive physical5
3
conditions in the PDRs associated with the Pillars. We estimate an average molecular gas density nH2 ⇠ 1.3 ⇥ 10 cm and43
an average atomic gas density nH ⇠ 1.8 ⇥ 10 cm and infer that the ionized, atomic, and molecular phases are in pressure
equilibrium if the atomic gas is magnetically supported. We find pillar masses of 103, 78, 103, and 18 solar masses for P1a,
P1b, P2, and P3 respectively, and evaporation times of ⇠1-2 Myr. The dense clumps at the tops of the pillars are currently
supported by the magnetic field. Our analysis suggests that ambipolar diﬀusion is rapid and these clumps are likely to collapse
within their photoevaporation timescales.

A resolved rotating disk wind from a young T Tauri star in the Bok globule CB26

R. Launhardt, Ya. N. Pavlyuchenkov, V. V. Akimkin, A. Dutrey, F. Gueth, S. Guilloteau, Th. Henning,
V. Pietu, K. Schreyer, D. Semenov, B. Stecklum, T. 30
L. Bourke F The disk-outflow connection plays a key role inP1b, P2, and P3 respectively, and evaporation times of ⇠1-2 Myr. The dense clumps at the tops of the pillars are currently
supported by the magnetic field. Our analysis suggests that ambipolar diﬀusion is rapid and these clumps are likely to collapse
within their photoevaporation timescales.

A resolved rotating disk wind from a young T Tauri star in the Bok globule CB26

R. Launhardt, Ya. N. Pavlyuchenkov, V. V. Akimkin, A. Dutrey, F. Gueth, S. Guilloteau, Th. Henning,
V. Pietu, K. Schreyer, D. Semenov, B. Stecklum, T. L. Bourke F The disk-outflow connection plays a key role inextracting excess angular momentum from a forming protostar. We have previously reported the discovery of a small molecular
outflow from the edge-on T Tauri star in the Bok globule CB26 that shows a peculiar velocity pattern, reminiscent of an outflow
that corotates with the disk. We report new, high-resolution mm-interferometric observations of CB26 with the aim of revealing
the morphology and kinematics of the outflow at the disk-outflow interface. The IRAM PdBI was used to observe CO(2-1) at
1.3mm with a resolution of 0.5". Using a physical model of the disk, which was derived from the dust emission, we employedchemo-dynamical modeling combined with line radiative transfer to constrain kinematic parameters and to construct a modelof the CO emission from the disk that allowed us to separate the emission of the disk from that of the outflow. Our observations
confirm the disk-wind nature of the rotating molecular outflow from CB26. The new high-resolution data reveal an X-shaped
morphology of the CO emission close to the disk, and vertical streaks extending from the disk surface with a small half-opening
angle of 7deg, which can be traced out to vertical heights of 500au. We interpret this emission as the combination of the disk
atmosphere and a well-collimated disk wind, which we trace down to vertical heights of 40au, where it is launched from thesurface of the flared disk at radii of 20-45au. The observed CO outflow has a total momentum flux of 1e-5 Msun km/s/yr, which
is nearly three orders of magnitude larger than the maximum thrust that can be provided by the luminosity of the central star.
We conclude that photoevaporation cannot be the main driving mechanism for this outflow, but it must be predominantly an
MHD disk wind. It is thus far the best-resolved rotating disk wind observed to be launched from a circumstellar disk.

Testing external photoevaporation in the -Orionis cluster with spectroscopy and disk
mass measurements
31

K. Maucó, C. F. Manara, M. Ansdell, G. Bettoni, R. Claes, J. Alcala, A. Miotello, S. Facchini, T. J. Haworth, G.