星形成ゼミ 2019/6/21 (辰馬)2. The Origin of [CII] 158um Emission toward the HII Region Complex S235
3. Physical and chemical ﬁngerprint of protostellar disc formation
4. Sub-millimeter non-contaminated detection of the disk around TWA 7 by ALMA
5. A survey of C2H, HCN, and C18O in protoplanetary disks
6. Tiny Grains Shining Bright in the Gaps of Herbig Ae Transitional Discs
7. ALMA survey of Class II protoplanetary disks in Corona Australis: a young region with low disk
masses
8. Multi-line Observations of Molecular Bullets in A High-mass Protostar
9. Oscillatory migration of accreting protoplanets driven by a 3D distortion of the gas ﬂow
10. Bok globule CB 17: Polarization, extinction and distance
11. TRAO Survey of Nearby Filamentary Molecular clouds, the Universal Nursery of Stars (TRAO
FUNS) I. Dynamics and Chemistry of L1478 in the California Molecular Cloud!1

7

L. Testi2 , J. P. Williams8 , C. Carrasco-González9 , R. Dong10 , J. Forbrich11,12 , M. Fukagawa13 , R. Galván-Madrid9 ,
4,14
15
16
17
3
13,18,19
N.ALMA
Hirano3 , M.
Hogerheijde,
Y.
Hasegawa
,
T.
Muto
,
P.
Pinilla,M.
Takami,M.
Tamura,survey of ClassII
protoplanetarydisks
inCoronaM. Tazzari20 , and J. P. Wisniewski21

Australis: a young
region with low disk masses(Affiliations can be found after the references)?

P. Cazzoletti1 , C. F. Manara2 , H. Baobab Liu2,3 , E. F. van Dishoeck1,4 , S. Facchini2 , J. M. Alcalà5 , M. Ansdell6,7 ,Received 14 February
2019 /10Accepted 3 April11,12
2019
2
8
9
L. Testi , J. P. Williams , C. Carrasco-González , R. Dong , J. Forbrich, M. Fukagawa13 , R. Galván-Madrid9 ,N. Hirano3 , M. Hogerheijde4,14 , Y. Hasegawa15 , T. Muto16 , P. Pinilla17 , M. Takami3 , M. Tamura13,18,19 ,M. Tazzari20ABSTRACT, and J. P. Wisniewski21
Context. In recent years, the disk populations
in a number
young
regions have been surveyed with the Atacama Large(Affiliations
canofbefoundstar-forming
after the references)Millimeter/submillimeter Array (ALMA). Understanding the disk properties and their correlation with the properties of the central
star is critical to understanding planet formation. In particular, a decrease of the average measured disk dust mass with the age of the
14 February/ Accepted 3 April 2019
region has been observed, consistent withReceived
grain growthand disk2019
dissipation.
Aims. We aim to compare the general properties of disks and their host stars in the nearby (d = 160 pc) Corona Australis (CrA) star
forming region to those of the disks and stars in other regions.
ABSTRACT
Methods. We conducted high-sensitivity continuum ALMA
observations of 43 Class II young stellar objects in CrA at 1.3 mm(230 GHz). The typical spatial resolution is ⇠0.300 . The continuum fluxes are used to estimate the dust masses of the disks, and aContext.
In recentis years,
the disk
populations
in a numberof young
star-forming
have been surveyed
Largesurvival analysis
performed
to estimate
the average
dust mass.
We alsoobtained regions
new VLT/X-shooter
spectra withfor 12theof Atacama
the objectsinMillimeter/submillimeter
Array(ALMA).
Understanding
the disk properties and their correlation with the properties of the central
our sample for which spectral
type(SpT) information
was missing.
star
is criticalto understanding
planetformation.
In particular,
decreaseof themeasureddiskofdust
with the ageof theResults.
Twenty-fourdisks weredetected,and stringent
limits ahave
been puton average
the average
dust mass
themass
nondetections.
Takingregionhas been
consistent
with grain
growthinto accounttheobserved,
upper limits,
the average
disk massin andCrAdiskis 6 dissipation.
± 3 M . This value is significantly lower than that of disks in otherAims.
to starcomparethe regions
general (Lupus,
propertiesof disks
and their I,
hostin the nearby(d = 160
Corona Australis
staryoung We
(1–3aimMyr)
forming
Taurus,Chamaeleon
andstars
Ophiuchus)
and appears
to pc)
be consistent
with the(CrA)
averageforming
regionthoseMyr-oldof the disks
and
stars
inposition
other regions.
disk massof theto5–10
Upper
Sco.
The
of the stars in our sample on the Herzsprung-Russel diagram however seems
Methods.
continuum
ALMA
observationsof 43 Class
young stellar objects
in CrA
at 1.3 mm
to confirmWe
thatconducted
CrA has anhigh-sensitivity
age similar to Lupus.
Neither
external
photoevaporation
nor aIIlower-than-usual
stellar mass
distribution
00
(230
GHz).
The
typicalspatialresolution
is
⇠0.3
. The
continuum
are used
to estimate
the dustof thesmall,disks,whichand acan explain the low disk masses. On the other hand,a low-mass
diskfluxes
population
could
be explained
if themasses
disks were
survival
analysisis performed
to hadestimateaverage dust
mass. Wealso obtained
newor
VLT/X-shooter
spectra for 12
objects
could happen
if theparent clouda lowthetemperature
or intrinsic
angularmomentum,if the angular momentum
of ofthethecloud
wereinoursamplewhich
spectraltype (SpT)
information
was
missing.
removedbyforsomephysicalmechanismsuch
as magnetic
braking.
Even in detected disks, none show clear substructures or cavities.
Results.
Twenty-fourdiskssuggest
were detected,
and tostringent
limitsandhaveunderstandbeen put on
dust mass of protoplanetary
the nondetections.
Conclusions.
Our resultsthat in order
fully explain
the thedustaverage
mass distribution
disksTaking
andinto
the itupperaveragetodisk
CrA is 6 ± 3theM initial. Thisconditions
value is significantly
than that ofdisks inother
theiraccountevolution,
may limits,also bethe
necessary
takemass
intoinconsiderationof star- andlower
disk-formation
process.
These
young
(1–3 atMyr)
regions(Lupus, Taurus,
Chamaeleon
and Ophiuchus)
to bethe average
conditions
the starveryforming
beginning
may potentiallyvary fromregion toI, region,and couldand
playappears
a crucialroleconsistentin planetwith
formationanddiskmass of the 5–10 Myr-old Upper Sco. The position of the stars in our sample on the Herzsprung-Russel diagram however seems
evolution.
to confirm that CrA has an age similar to Lupus. Neither external photoevaporation
nor a lower-than-usual stellar mass distribution
https://www.aanda.org/articles/aa/pdf/2019/06/aa35273-19.pdf
Keyexplain
words.theprotoplanetarydisks On– submillimeter:
ISM– planets andformation– stars:
pre-main– small, whichcanlow disk masses.
the other hand,a low-mass
disksatellites:
population
could beexplained
if thesequencedisks werestars: happen
variables:
T Tauri,– stars:formationor intrinsic angular momentum, or if the angular momentum of the cloud were
could
if theparentHerbig
cloud Ae/Be
had a lowtemperature!2
removed by some physical mechanism such as magnetic braking. Even in detected disks, none show clear substructures or cavities.

ALMA survey of Class II protoplanetary disks in Corona Australis:a young region with low disk masses
背景：古い星形成領域ほど、平均円盤ダスト質量が低い＝ダスト成長と円盤散逸(3-5 Myr)を示している。
目的：Corona Australis (CrA)星形成領域(160 pc)とその他の領域の、円盤と中心星の性質を比較した。
方法：ALMA Band 6の1.3 mm連続波で43個のClass II天体を観測(空間分解能0.3”)。円盤ダスト質量を見積もっ
A&A proofs: manuscript no. CrA_publisher
た。スペクトルタイプが不明な12天体に関してはVLT/X-Shooterのスペクトルも新たに得た。

A&A proofs: manuscript no. CrA_

星のスペクトルは
Lupusと似ている✓maj ⇥ ✓minresolution
presented
It is imthe observ
have been
to 1500 eas
had to be
therefore b

3.2. VLT/X(☆はR CrA)(FS = Flat Spectrum)

Fig. 1: Spatial distribution of the CrA sources from the Peterson et al. (2011) catalog on top of the Herschel 250 µm map of the CrA
molecular cloud. The di↵erent colors represent the classification of the YSOs. The blue star indicates the position of R CrA.

!3

Fig. 2: Distribution of the SpTs of the stars in CrA (Red) compared to that of Lupus (Orange) and Upper Sco (Blue).

The spectr
missing Sp(PI Manar
VLT/X-Sh
ment covesimultaneo( ⇠ 300(⇠ 100
narrow sli

However, it should be noted that the average right ascension
Project baseline lengths (min-max) [m] 14-1108
15-1075
15-1110anddeclinationo↵setsbetween
the
disks
and
the
Spitzer
posiAbsolute
flux Corona
calibrator
PallasPallasPallas
ALMAtions,surveyofClassIIprotoplanetaryinAustralis:Fig.
4:Comparisonofthecumulative
dust
mass
distributions o
00disks
calibrator
J1937-3958
J1924-2914
J1924-2914
measured on the detections, are < ↵ >= 0.13 and Gain
Bootstrapped gain calibrator flux [Jy]
0.26
3.9
4.1
Lupus,
CrA,
Cham
I,
Ori
and
Upper
Sco,
derivedusing a sur
00
Passband calibration
J1924-2914
J1924-2914
J1924-2914
<
>=
0.47
respectively:
itisthereforepossiblethatthe
una young region with low disk masses
Bootstrapped passband calibrator flux 4.1
3.9
4.1
vival
analysisaccounting
for
the
upper
limits.
detected sources did not overlap during the stacking, and that the [Jy]binary
upper
limit
is
actuallyhigherthanthatquoted.
結果：
content
10 M 3 and are therefore large enough to form th
24個の円盤を検出。非検出の平均ダスト質量に強い制限
core of a giant planet in the future. However, it is still possibl
4.3. Dust masses
that a similar amount of dust mass is hidden in the inner dis(3σ=0.036地球質量)をつけられた。CrAの平均円盤質量
Assuming that the observed sub-millimeter emission is optically regions 50due
au
to
very
high
opticaldepth(e.g.,
Zhu
et
al.
2010
は6 3地球質量。これは他の若い(1-3
Myr)領域(Lupus,
thin and isothermal, the relation between the emitting dust mass Liu et al. 2017; Vorobyov et al. 2018). We also note that ver
Taurus,Chamaeleon
I, Ophiuchus)よりも非常に低い。
(Mdust) and the observed
continuum flux at frequency ⌫ (F⌫ ) is recent high-angular-resolution ALMA and VLA observations oasfollows(Hildebrand1983):
disks are revealing that an important amount of dust is located i
一方、5-10 MyrのUpper Scoの平均円盤質量とは一致。
dense regions such as rings (e.g., Andrews et al. 2018), which ar!22
optically thick at wavelengths around 1 mm (Dullemond et alF⌫ dd6
Mdust = P. Cazzoletti etA&A
⇡
2.19
⇥
10
F
[M
],
(2)
1.3
mm
2018). When optically thin emission is detected, higher masse
proofs:manuscript
no.
CrA_publisher
al.:
ALMA
band
6
survey
for
Class
II
YSOs
in
CrA
⌫ B⌫ (T dust )160
are estimated (Carrasco-González et al. 2016).
Table
4: in
Globalpropertiesof theregions
naries)the imageplane using
the star-forming
imfit task in CASA.
Thesurveyedtask
Thestackingof
thenondetections
gives
anaverage3
uppe
returns
the total
flux-density
with
ALMA
in orderof age.F1.3 mm of the source along with the
UScoと似ている
whered isalong
thethedistanceof) the object, F
statistical uncertainty,
the FWHM
semi-major (amaj⌫ is the measured fluxlimit corresponding to 0.036 M , or about three lunar masses.
and semi-minor (amin ) axis, and the position angle (PA). The redensity,B3⌫2(T) is dust
themass
Planckfunction for a given dust temperName
Distance
Averagedust
sults
of the fit are shownin TableAge. The
right ascension( ↵)[pc] with[Myr][M ] coordiand declination ( ature) o↵sets
respect
to theSpitzer
T
,
and

is
the
dust
opacityatfrequency
⌫.
To
make
the
dust
⌫
nates
are also shown.129.5
The 1rms noise
Taurus
1-3for the00nondetections
13 ± 2 was
4.4.
Comparison
with
other
regions
comparison
previous
calculated using theimstata 1 radius
centered at surveys easier, for the dust opacity ⌫
1,? task withinwith
160for the detection,
1-3 it was calculated
14 ± 3 in an
theLupus
Spitzer coordinates;
1
we154follow
of Ansdell et al. (2016), assuming
CrA region centered
1-3the6 ±approach
3 outerannularon the sourceand samewith innerandThe surveys of nearby star-forming regions over the last year
00 1
1 24 ± 9
Chameleon
192
2-32
radii
equal to 200I and
4,
respectively.

=
at
1000
GHz
(Beckwith
et
al.
1990)
and
scaling⌫
110 cm g
ICIn348
321the average
2-3flux density of4 individually±1order to constrain
have shown growing evidence of a decrease in the mass of th1
undetected
to ouranalysis
frequency
Ori sources,ita stacking
388
3-5 was also performed.
7 using± 1 The = 1. The adopted value is therefore
disks with age, reflecting dust growth and disk dispersal. Ans
3imagesat their
Spitzercoordinates
1) and2
1 5(Table
Upperwere
Scocentered
144
5-10
±
3
cmnogdetection
at was⌫ found= 230 GHz (1.3 mm). In the right-handthen stacked. Even⌫after=the2.3
stacking,dell et al. (2016, 2017) found consistent results, calculating th
Dzib
et al.
(2) Comerón(2008) (3) deandReferences.
the average(1)
rms
noise
is (2018)
0.017 mJy
beam 1 , corresponding
side?ofEq.
2,distancetheunresolved
distanced is measured in parsecs and the flux
Zeeuw
et al. (1999)
ThemJyaverageofthe 4 Lupus
toIC
a 3 348は例外
upper
limit of 0.051
assuming
disks.
highest average mass in the youngest regions (1-3 Myrs), and th
clouds wasused.density
However,it should
be noted thattheaveragerightascensionF
isinmillijanskys.
Foreachobject,theaverage
1.3
mm
anddeclination o↵setsstellar
between thepopulation)
disks and the Spitzer posi(low-masslowestfortheoldestUpper
Scoassociation(5-10Myrs).
The
2
Fig.
4:
Comparisonofthecumulative
dust
mass
distributionsof00!4 tem- Fig. 3: ALMA Band 6 1.3 mm continuum images of the 24 detections in CrA. The size of the images is 3 ⇥ 3 . The size of the
of
=
154
pc
was
used.
For
the
dust
tions, measured ondistancethe detections,arethe< ↵cluster>= 0.13 dand
Lupus, CrA, Cham I, Ori and Upper Sco, derived using a sur- 3 Myr-old IC348 is the only exception, showing an average dus
00
EpochTime (UTC; 2016)

1(Aug.01) 03:32-04:54

00

2(Aug.01) 05:01-06:2300

3(Aug.02) 03:18-04:40

00

00

ALMA survey of Class II protoplanetary disks in Corona Australis:A&A proofs: manuscript no. CrA_publisher

a young region with low Table
disk
masses4: Global properties of the star-forming regions surveyed
with ALMA in order of age.

しかし、HR図上ではCrAはLupusと同じ年齢を示す。なぜ円盤質量が低
いのか？

Name

Distance
[pc]

Age
[Myr]

Average dust mass
[M ]Taurus129.51
1-3
13 ± 2
元となる分子雲が、低温/固有の角運動量が低かった/磁気ブレーキなど
Lupus
1601,?
1-3
14 ± 3
CrA
154 1
1-3
6±3
で角運動量が取り除かれた、のいずれかであれば、円盤が小さくなり、
Chameleon I
1921
2-3
24 ± 9IC 3483211
2-3
4±1
低い円盤質量が説明できる。Class 0Ori
& I天体の円盤質量を観測すべき。
3881
3-5
7±1
Upper Sco
1443
5-10
5±3

UScoと
似ている

他のあり得るシナリオは除外された。low
References.metallicity(1) Dzib et al. (2018)(低くない),(2) Comerón (2008) (3) deZeeuw et al. (1999)
clouds was used.

? The average distance of the 4 Lupus

external photo-evaporation (最も明るいR CrAからの距離と円盤質量に相関がないし、光蒸発できるほどFUVフラックスは高くない), low

a separate evolutionary stage, are excluded. Finally, in order tofacilitate the comparison
with the other samples, in this analystellar mass population, tidal interaction(denseじゃないし、速度分
sis we only include the disks around stars with masses above
the brown-dwarf limit (M? 0.1 M ). The Kaplan-Meier esti散も低い、binaryも少ない)
mator from the lifelines4 and ASURV (Lavalley et al. 1992)
packages were then used to estimate the cumulative mass distri結論：原始惑星系円盤のダスト質量分布やその進化を説明するには、
bution and to calculate the average dust mass and its uncertainty
while properly accounting for the upper limits by using well星・円盤形成過程の初期条件(領域によって大きく異なる)を考えなければ
established techniques for left-censored data sets.
Figure 4 presents the results accounting for the upper limits
ならない。
given by the nondetections. With an average dust mass of 6 ±3 M , the distribution of the CrA disks appear closer to that of
the old Upper Sco region rather than to those of the younger
systems.
4.5. Mdisk

M? relation!5

P. Cazzoletti et al.: ALMA band 6 sur

Fig. 5: Correlation between dust disk flux scaled at 330 GHz(assuming ↵ = 2.25, as in Ansdell et al. 2018) and at a distanceof 150 pc with stellar mass for the objects in CrA. The slopes of
Lupus and Upper Sco are also plotted for comparison. We show
the results of the Bayesian fitting procedure by Kelly (2007).
The solid line represents the best-fit model, while the light lines
show a subsample of models from the chains, giving an idea ofthe uncertainties.
one (CrA-42) shows a clear Lupusとdetection of a disk at mm wavelengths. For the four nondetections, the stellar mass is therefore
似ている
randomly drawn among the massesof the stars with nondetecteddisks, while the mass of CrA-42 is drawn from those showing
a detection with ALMA. This uncertainty is also taken into account in the Bayesian approach we adopt by performing 100 different draws. In our fit, a standard uncertainty of 20% of M?
Fig. 6: HR diagram showing the sources in our CrA sample (red),

ob
HR
an
Sc

ue
sh
clu
als
mo
jec
sc

5.2

If
me
flu
Ho

[astro-ph.EP] 29 Apr 2019

O. Chrenko and M. Lambrechts

91

Oscillatory migration of accreting protoplanets
driven by a 3D distortion of the gas flow

Institute of Astronomy, Charles University in Prague, V Holešovičkách 2, CZ–18000 Prague 8, Czech Republic
e-mail: chrenko@sirrah.troja.mff.cuni.cz
2Lund Observatory, Department of Astronomy and Theoretical Physics, Lund University, Box 43, 22100 Lund, Sweden
Received ??; accepted ??

1
2
O. Chrenko and M. Lambrechts
ABSTRACT

Context. The dynamics
a low-mass protoplanetaccretingsolids is influenced
by the heatingPrague
torque, which
was foundto suppress
ute of Astronomy,CharlesofUniversity
in Prague,
V Holešovičkách
2, CZ–18000
8, Czech
Republic
inward migration in protoplanetary disks with constant opacities.
l: chrenko@sirrah.troja.mff.cuni.cz
Aims. We investigate the di↵erences of the heating torque between disks with constant and temperature-dependent opacities.
Observatory,
Astronomy andTheoretical
University,
Box 43,22100 Lund,
Sweden
Methods.Department
Interactions of ofa super-Earth-sized
protoplanetwith thePhysics,
gas disk areLund
exploredusing 3D radiationhydrodynamic
simulations.
Results. Accretion heating of the protoplanet creates a hot underdense region in the surrounding gas, leading to misalignment of thelocal density and pressure gradients. As a result, the 3D gas flow is perturbed and some of the streamlines form a retrograde spiralrising above
d ??; accepted??the protoplanet. In the constant-opacity disk, the perturbed flow reaches a steady state and the underdense gas responsible
for the heating torque remains distributed in accordance with previous studies. If the opacity is non-uniform, however, the di↵erencesin the disk structure can lead to more vigorous streamline distortion and eventually to a flow instability. The underdense gas develops
a one-sided asymmetry which circulates around the protoplanet in a retrograde fashion. The heating torque thus strongly oscillates intime and does not on average counteract inward migration.ABSTRACT
Conclusions. The torque variations make the radial drift of the protoplanet oscillatory, consisting of short intervals of alternating
rapid inwardof
anda outward
migration.
We speculatethat transitions
the positive
maywasoccurfoundin. The dynamics
low-mass
protoplanetaccretingsolids between
is influenced
by andtheoscillatory
heating heating
torque,torque
which
to s
specific
disk
regions
susceptible
toverticalconvection,
resultingintheconvergent
migrationofmultipleplanetaryembryos.
migration in protoplanetary disks with constant opacities.

Key words.
Hydrodynamicsof– thePlanetsand satellites:– Planet-disk
interactions
disks
We investigate
the di↵erences
heating
torqueformation
betweendisks withconstant– Protoplanetary
and temperature-dependent
opacities.
https://arxiv.org/pdf/1904.12497.pdf
s. Interactions of a super-Earth-sized protoplanet with the gas disk are explored using 3D
radiation hydrodynamic simu
!6
. Accretion heating of the protoplanet creates a hot underdense
region in the surrounding gas, leading to misalignmen

Oscillatory migration of accreting protoplanets driven by a 3D distortionof the gas ﬂow
背景：

前

惑星静止系

Type I migration: ガスにギャップをあけない小さな原始惑星が、リンドブラッド
共鳴の位置から発生する波(wake)や、共回転共鳴の位置にあるガスから重力トルクを受け、軌道を変化させる現象。

与える
(正)

リンドブラッド共鳴による正味のトルクは負（外側and temperature T (⌃ / r ↵ , T / r ), anが強い）なので、惑星を内向きに移動させる。
normalised by
2
q
4 2
共回転
与える
=
⌃
r
0
p p ⌦p ,2h
共回転共鳴による正味のトルクは正（惑星に角運動奪う(正)where q is the planet-to-star mass ratio, h量を与える方が強い）なので、惑星を外向きに移動(負) p reaspect ratio and quantities with subscript
tion of the planet. Note that in general we exさせる。
i.e. both surface density and temperature dec
For reasonable values of ↵, the wave torque o
共回転よりもリンドブラッド共鳴のほうが強いの
negative: it decreases the orbital angular mom
planet, and thus its semi-major axis (the plan
で、惑星は内向きに移動する。
奪う
circular orbit), leading
to inward migration.
proximation remains
valid as long as q ⌧ h(負)and Papaloizou, 1996). For a disc around a S
例えば地球だと移動タイムスケールは1万年ほどで、リンドブラッドwith h 後= 0.05 this means that the planet ma
円盤の寿命(100万年くらい)よりも短く、ガス円盤のmuch smaller than 40 M .
The factor in Eq. (1) is due to the differ中で中心星に落ちてしまう。
speed between isothermal and adiabatic diand Masset, 2008a). For etdiscs
can cool
5地球質量の惑星による、面密度の摂動の相対値(Baruteaual.that2014)
Fig. 1.— Relativeof theresult
surfaceof (a gas
expectperturbation
the isothermal
to density
be valid!
!7
protoplanetary
discthat
perturbed
a 5 efficiently,
Earth-mass theplanetlocatediscs
can notbycool
adiabati

opacity κ [cm2 g-1]

const
BL

aspect h=H/r
temperature T [K]γ

entropy P/ρ [c.u.]

temp

90
largest 4allowed time step
bk
<
10
,
where
the
norms
are
calculatedintheL
space.
Fig. 1. Radial profiles of the characteristic quantities in2
itation,itisadvantageous
60 Oscillatory
O. Chrenko andof
M. Lambrechts:
migration of accreting protoplanets
drivenby
a 3D
3D distortionof the gas flow
Oscillatory migration
accretingprotoplanets
drivenbyadistortion(dashed blue curves) and the BL -disk (solid black curv
mplicit form. We thus folnumericalrelaxation
over
t
=
100
P
.
From
top
to
botto
orb
of the gas
ﬂow
using
the
tapering
cubic-spline
function
f
of
Klahr
&
Kley
0.028
sm
10
nnitialproposedby(2006):
Bitschet al.
conditions
and parametersshow
theopacity,
aspect
ratio
h
=
H/r,
temperatureTanκ
protoplanet
0.025
location (or used
oducedin AppendixA.
κ to derive
ダストを降着している（＝ペブル降着）低質量原始惑星の円盤
P/⇢.
Midplanevaluesaredisplayed
8
0.022
conditions describing
the
disk
are
adopted
from
Kley
et
al.
>
(d
)
1
,
>
r
,
1
>
sm
verticalline
indicates
theprotoplanet’s
orbitaldistancea>p
em is内での内側への軌道移動は、加熱トルクによって抑制される。
obtained iteratively,
>
0.019
>
3density follows the!4 The surface!3<26) and Lega etfsmal.= (2014).
7
(10)
d
d
d
>
6
7
>
6
7
b,
where
A
is
the
ma0.0160.52(d  rsm )
>
6
7
0.2
2
+
2
,
>
6
7
冷たく暗い原始惑星の場合：降ってきたガスは圧縮の結果加熱-law function ⌃ = >:484(r/(1
au))
g
cm
.
The
initial⌃is
温度依存オパシティ
4 r
5
rsm
r0.013sm
sm
ution
vectorandb
isthe(Bell & Lin 1994)
rted into
the initial ⇢ assuming the disk0.01
is vertically isotherするが、放射冷却して高圧になる。この冷たく過密な領域は原
0.055
range
of
the
expected
pebbleaccretion
rates
(Lamb
lver
uses
the
improvedbiwhere thersm is a fractionof the protoplanet’s
The velocity
field
is smoothing
given bylengthbalancing
the gravitational
始惑星からのアウトフローに沿って現れ、この非対称性が負の
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
0.05
hansen2014;
Chrenkoetal.
2017).
The
resultinglHillsphereradius
(see
Sect.
2.2).
Orbitalevolutionoftheprotab;
Yang
&
Brent
2002)
rationトルクとなり、内側へ軌道移動させる。
from theprotostar,theacceleration
due
to
the
pres27
1
radialdistancer[au]
toplanet is tracked using the ias15 integrator (Rein & Spiegel the
0.045
protoplanet
is
L
'
4.2
⇥
10
erg
s
.
convergencecriterionis2
radient and theacceleration.
assigncon- we2015)centrifugal
from the reboundpackage (ReinWe& Liu2012), which
1521
熱く明るい原始惑星の場合：ダストの降着により原始惑星が熱
interfacedwithfargo3d.
alculatedviscosity
in the L2⌫space.
kinematic= 10 cmthe gasto mimic
Fig.s 1. toRadialprofilesof the characteristic quantities in the const -disk

entropy P/ργ [c.u.]

150
Althoughfargo3dis
anexplicithydrodynamic
solver,implegularくなると、周囲のガスも加熱し低密度となる。低密度領域は原
momentumtransport
in
the
disk
drivenbyphysical(dashedblue
curves)
and
the

-disk
(solidblack
curves)
after
their
BL
120
menting Eqs. (3) and (4) in an explicit form would lead to a very 2.3. Opacities
始惑星からのアウトフローに沿って現れ、惑星の後ろのほうがs outside
the restrictive
scope ofCourant
this study(e.g.
thelargest
turbulent
eddy
numerical
relaxationover= 100 Porb90. From top to bottom, the panels
conditionon theallowedtimet stepsity). The
length.
To avoidsuchisa show
advantageous
initialaspectratio
htime= stepH/r= 0.05,it,iswhereH
60 temperature
thelimitation,
opacity
aspectratio Usingh = H/r,T parameters,
and entropy Swe= setup two
支配的なため、惑星の前が相対的に過密となり、トルクは正theinitialdisk
to solve the energy equations in an implicit form. We thus folpressure
scalelowheight.
The
disk
is
therefore
initially
nonP/⇢.
Midplanevaluesaredisplayed
(or
used
to
deriveh).
The
dotted（＝加熱トルク）、すなわち惑星は外側へ軌道移動する。
models
that
only
di↵er
in
the
material
opacity
fu
0.028
the
discretisationandlinearisation
proposedbyBitschetal.
eadopted
from
Kley
et
al.
0.025orbital distance a = 5.2 au.
g but we point(2013),
our with
thata hminor
evolvesduringsimulations.
verticallinetheindicates
the protoplanet’s
modification
introducedin Appendix
A. opacity
por follows a slightly modiseitherconstant
0.022
目的：一定＆温度依存のオパシティについて、それぞれの加熱
urfacedensityfollows
theThe=
solutionofthe theimplicit
problem
is obtained
iteratively, low) prescription
diabatic
index
is
1.43
and
mean
molecular
weight
0.019
of
Bell
&
Lin
(1994).
To
distingu
0.5 トルクを調べた。
21 by minimizing the residual r ⌘ Ax b, where A is the ma0.016
g
cm
.
The
initial⌃is
2.3 g mol , corresponding
to
the
solar
mixtureofthehywe use the abbreviations const -disk a
0.013
trix of the linear system, x is the solution vector and b is the the models,disk方法：3D輻射流体力学シミュレーションで、3地球質量の原始is vertically
isother0.01
ne andhelium.
right-hand side vector. Our iterative solver uses the improved bi- respectively.
The
exact
value
of
the
opacity
in
the
range
of
the
expected
pebbleaccretion
rates(Lambrechts
&
Jo3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
method(IBiCGStab; with
Yang &
2002) tuned to be the same as in the  -disk at the loc
theconjugateealancingwill惑星とガス円盤の相互作用を調べた。
assumeagravitational
singlestabilised
embeddedsuper-Earth
theBrent
mass
radial distance r [au]BL
hansen2014;
Chrenkoetal.
with the Jacobi preconditioning.
The
convergencecriterion
is 2017). The resulting luminosity ofceleration
due
to
the
pres3 M , orbiting
on
a
orbit
at
the Jupiter’s
he4
to

⌘

(r
=
a
)
=
1.1
!8space. protoplanet
271. Radial profiles
1ap , leading
const
BL
p
krk/kbk < 10 circular, where the
norms
are
calculated
in
the
L
Fig.
of
the
characteristic
quantities
in
the

-disk
2
const
the protoplanet is L ' 4.2 ⇥ 10 erg s .

Oscillatory migration of accreting protoplanets
drivenbya
3D
distortion
O. Chrenko and M. Lambrechts: Oscillatory migration of accreting protoplanets driven by a 3D distortion of the gasof the gas ﬂow
結果：降着熱は周辺ガスに熱く低密度な領域を作り、cold non-luminous protoplanet (const -disk simulation, t = 30 Porb )perturbed density
temperature

原始惑星の上には公転方向と逆回りの渦状アウトフ
ローができた。
オパシティ一定の場合：定常状態となり、加熱トルク
は従来の描像と同じになった。
オパシティ非一様の場合：低密度なガス領域が原始惑星の周りを公転方向と逆回りし、加熱トルクは振動A&A proofs: manuscript no. paper
し、原始惑星の内側への移動を食い止めることはでき

ons

ally depends on thewell-established disk4) (in the azimuthalet (2017) (in the raom rmin = 3.12 au to
We prevent any ver-total torque Γ [aJ2 ΩJ2]

unmodified opacity
なくなった。 4e-05
nge our conclusions.
3e-05
iscussed throughout
n of Sect. 3.6 where
2e-05
orque on the opacity
1e-05

Cold protoplanet

Hot protoplanet

hot luminous protoplanet (const -disk simulation, t = 60 Porb )perturbed density
temperature excess

負のトルク＝内側へ軌道移動0-1e-05-2e-05-3e-05κconstκBL-4e-05-5e-05
0

10

20

30
40
no. of orbits [Porb]

50

60○はヒル半径(原始惑星の重力が及ぶ範囲)
9!
Fig. 3. Hydrodynamic quantities in the midplane of the const -disk close to the protoplanet. Top row corresponds to the cold

Oscillatory migration of accreting protoplanets
drivenbya
3D
distortion
O. Chrenko and M. Lambrechts: Oscillatory migration of accreting protoplanets driven by a 3D distortion of the gas flow

rear方向から見たとき
cold protoplanet (const -disk simulation, t = 30 Porb )↓of the gas ﬂow
0.15

front

結果：降着熱は周辺ガスに熱く低密度な領域を作り、0.1

原始惑星の上には公転方向と逆回りの渦状アウトフ

1.55は従来の描像と同じになった。

colatitude

0

inner

オパシティ一定の場合：定常状態となり、加熱トルク

1.555

outer

ローができた。

azimuth θ [rad]

0.05

1.56

-0.05

1.565

-0.1

1.57
5.1
5.15

rear

オパシティ非一様の場合：低密度なガス領域が原始惑

-0.15
5.05

5.1

5.15

5.25
5.3

-0.05

0
uth
azim

0.15

front

Hot protoplanet
0.1

1.54

-0.05

-1e-05-2e-05colatitude

0

inner

負のトルク
＝内側へ軌道移動

0

1.545

0.05
azimuth θ [rad]total torque Γ [aJ2 ΩJ2]

ally depends on thewell-established disk4) (in the azimuthalet (2017) (in the raom rmin = 3.12 au to
We prevent any ver-

5.35

outer

ons

5.3

0.05

hot protoplanet (const -disk simulation, t = 60 Porb )し、原始惑星の内側への移動を食い止めることはでき
Cold protoplanet

5.25

radius r [au]星の周りを公転方向と逆回りし、加熱トルクは振動A&A proofs: manuscript no. paper

unmodified opacity
なくなった。 4e-05
nge our conclusions.
3e-05
iscussed throughout
n of Sect. 3.6 where
2e-05
orque on the opacity
1e-05

5.2

ra 5.2
diu
s

1.55
1.555
1.56
1.565
1.57
5.1

-0.1

5.15

-3e-05rearκconstκBL-4e-05

-0.15
5.05

5.15

5.2
radius r [au]-5e-05
0

5.1

10

20

30
40
no. of orbits [Porb]

50

5.25

5.3

5.35

ra 5.2
diu
s

5.25
5.3

-0.05

0
uth
azim

0.05

60

Fig. 5. Detailed streamline topology in the const -disk simulation. Top row corresponds to the cold protoplanet at t = 30 Porb and the bottom row to
the hot protoplanet!10 at t = 60 Porb . Rectangular projection in the spherical coordinates is used to display the disk midplane near the protoplanet (left)
and the actual 3D flow (right). The colour of the curves distinguish individual sets of streamlines: inner circulating (yellow), outer circulating (red),○はヒル半径(原始惑星の重力が及ぶ範囲)

Oscillatory migration of accreting protoplanets driven by a 3D distortionof the gas ﬂow① 原始惑星の前方に渦を作るガス流のほとんどが、後ろのホースシューから来ているとき → 熱く低密度なガスは前方にたまる → トルクは後ろからの寄与が大きくなり負となる（＝最小トルク）② 渦と前のホースシューが完全に切り離されたとき → 後ろのホースシューからのガス流の一部は、渦とならずに原A&A proofs: manuscript no. paper

始惑星を越してUターンする → 同時に、渦は惑星の後ろに移動する → トルクは負から正へ
hot protoplanet (BL -disk simulation)③ ①と逆のことが起き、トルクは①

正になる（＝最大トルク）②④ ②と逆のことが起き、トルクはnuscript no. paper

正から負へ、そして①に戻る
Cold protoplanet

4e-05

Hot protoplanet

2

1e-05

total torque Γ [aJ ΩJ ]

2e-05

2

3e-05

0
-1e-05-2e-05-3e-05κconstκBL-4e-05-5e-05
0

10

20

30
40
no. of orbits [Porb]

50

60

!11

③

④

Oscillatory migration of accreting protoplanets driven by a 3D distortionof the gas ﬂow

O. Chrenko and M. Lambrechts: Oscillatory migration of accreting protoplanets driven by a 3D distortion of the gas flow(a) t = 31.3 Porb(c) t = 31.75 Porbのほとんどが、後ろのホース

0.15

シューから来ているとき → 熱く

0.1

0.1

0.1

低密度なガスは前方にたまる →

0.05

0.05

0.05

-0.05

-0.05

-0.1

-0.1

-0.1

rear

シューからのガス流の一部は、渦

5.1

5.15

5.2
5.25
radius r [au]

rear
5.3

-0.15
5.05

5.35

(d) t = 31.95 Porb

5.1

5.15

5.2
5.25
radius r [au]

rear
5.3

-0.15
5.05

5.35

(e) t = 32 Porbとならずに原始惑星を越してUターンする → 同時に、渦は惑星

0.1

0.1

0.1

の後ろに移動する → トルクは負

0.05

0.05

0.05
azimuth θ [rad]

0

-0.05

-0.05

-0.05

-0.1

-0.1

-0.1

rear
-0.15
5.05

5.1

5.15

5.2
5.25
radius r [au]

rear
5.3

!12

5.35

5.3

5.35

front

inner

azimuth θ [rad]

front

inner

azimuth θ [rad]

front

0

5.2
5.25
radius r [au]outerになる（＝最大トルク）

5.15

0.15

outer

③ ①と逆のことが起き、トルクは正

0.15

outer

から正へ

5.1

(f) t = 32.15 Porb

0.15

0

inner

0

-0.05

-0.15
5.05

り離されたとき → 後ろのホース

azimuth θ [rad]innerazimuth θ [rad]innerazimuth θ [rad]

0

front

outer

② 渦と前のホースシューが完全に切

0

front

outer

なり負となる（＝最小トルク）

0.15

front

outer

トルクは後ろからの寄与が大きく

0.15

inner

① 原始惑星の前方に渦を作るガス流

hot protoplanet (BL -disk simulation)(b) t = 31.35 Porb

-0.15
5.05

5.1

5.15

5.2
5.25
radius r [au]

rear
5.3

5.35

-0.15
5.05

5.1

5.15

5.2
5.25
radius r [au]

5.3

5.35

iv:1904.12029v1 [astro-ph.GA] 26 A

2

I. Physikalisches Institut der Universität zu Köln, Zülpicher Stra e 77, 50937, Köln, Germany
8 CEA-Saclay, Gif-sur-Yvette, France 91191
The Originof [C II] 158 µm Emission toward the H II Region Complex S235
9 Institute of Astronomy of the Russian Academy of Sciences, Moscow, Russia 119017
10 Ural Federal University, Astronomical Observatory, Lenin 51, Ekaterinburg, Russia, 620083
1, 2,
3
1
1, 3
4
5
6

L. D. Anderson,
Z. Makai, M. Luisi,
M. Andersen, D. Russeil, M. R. Samal, N. Schneider,
P. Tremblin,8 A. Zavagno,5 M. S. Kirsanova,9, 10 V. Ossenkopf-Okada,7 and A. M. Sobolev10

7

ABSTRACT
1 Department 2of Physics
andAstronomy,
University,
WV 26506
Although the P3/2 2 P1/2
transitionof [CWestII] at Virginia' 158 µm
is knownMorgantown
to be an excellent
tracer of
2 Adjunct
Astronomer
Bank
Observatory,
P.O. Box of2, where
Green within
Bank WV
activestar formation,
we atstillthedoGreennot havea complete
understanding
star 24944
formation
regionsWaves
the emission
originates. West
Here,Virginia
we use SOFIA
upGREATobservationsof [C II] Building,emission toward
ter for Gravitationaland Cosmology,
University,
Chestnut
Ridge Research
Morgantown, WV 26
the H II region 4complex
Sh2-235Casilla(S235)603,
to betterunderstandin detail the origin of [C II] emission.
Gemini South,
La Serena,
Chile 0000-0002-5306-4089
We complement
data
with
a
fully-sampled
Green
Bank
Telescoperadio
recombinationline
map
5 Aixthese
Marseille University, CNRS, CNES, LAM, Marseille, France 13388
tracing theionized hydrogen gas. About half of the total [C II] emission associated with S235 is spatially
6 PhysicalResearch Laboratory, Navrangpura, Ahmedabad, Gujarat 380009, India
coincident
with ionized hydrogen gas, although spectroscopic analysis shows little evidence that this
7 I. Physikalisches
Institut der Universität zu Köln, Zülpicher Stra e 77, 50937, Köln, Germany
emission is coming from the8 ionized hydrogen volume. Velocity-integrated [C II] intensity is strongly
CEA-Saclay,
Gif-sur-Yvette,
France91191
correlated with WISE 12 µm intensity across the entire complex, indicating that both trace ultra-violet
9 Institute of Astronomy of the Russian Academy of Sciences, Moscow, Russia 119017
radiation fields. The 22 µm and radio continuum intensities are only correlated with [C II] intensity in
10 Ural Federal University, Astronomical Observatory, Lenin 51, Ekaterinburg, Russia, 620083
the ionized hydrogen portion of the S235 region and the correlations between the [C II] and molecular
gas tracers are poor across the region. We find similar results for emission averaged over a sample
of external galaxies, although the strengthABSTRACTof the correlations is weaker. Therefore, although many
tracers are correlated with the strength of [C II] emission, only WISE 12 µm emission is correlated on
22
Although
the P3/2
P1/2 transitionof S235[C II]andat also'has158µm iscorrelation
known toatbe
excellentsmall-scalesof the individual
H II region
a decent
thean
scale
of entire tracer ofactive starformation,
stillofdo
not have
a ofcomplete
understanding
where
withinwhether
star formation
galaxies.
Future westudiesa larger
sampleGalactic H
II regions would ofhelp
to determine
theseresults are
truly representative.
regions theemissionoriginates.
Here, we use SOFIA upGREAT observations of [C II] emission toward

the H II region complex Sh2-235 (S235) to better understand in detail thehttps://arxiv.org/pdf/1904.12029.pdf
origin of [C II] emission.
Keywords: H II regions – infrared: ISM – radio continuum: ISM – techniques: photometric
We complement these data with a fully-sampled Green Bank Telescope radio recombination line map!13
tracing the ionized hydrogen gas. About half of the total [C II] emission associated with S235 is spatially3904.13161v1 [astro-ph.SR] 30 Apr 2019

4

The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
5
Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße 1, 85748, Garching bei München, Germany
6
Department of Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan

Physical and chemical fingerprint of protostellar disc formation
May 1, 2019

E. Artur de la Villarmois1 , J. K. Jørgensen1 , L. E. Kristensen1 , E. A. Bergin2 , D. Harsono3 , N. Sakai4 , E. F. van
Dishoeck3, 5ABSTRACT, and S. Yamamoto6
protoplanetary
discforat thetime
when
the staris still gaining
mass. Itofis Copenhagen,therefore essential
to identify
and 5–7,
study 1350
the physicalNielswithin
BohrtheInstitute& CentreStar
andPlanetFormation,
UniversityØster
Voldgade
Copenhagenprocesses at play in the gas and dust close to young protostars and investigate the chemical composition of the material that is inherited
K., Denmark
from the parental cloud.
e-mail: elizabeth.artur@nbi.ku.dk
Aims. The purpose of this paper is to explore and compare the physical and chemical structure of Class I low-mass protostellar sources2
Departmentof Astronomy,
University of Michigan, 311 West Hall, 1085 S. University Ave, Ann Arbor, MI 48109, USAonprotoplanetary
disc
scales.
3
LeidenObservatory,
LeidenUniversity,
9513, NL-2300
Leiden, theNetherlands
Methods.
We present
a studyof the dustPO
and Boxgas emission
towards a RA
representative
sampleof 12 Class I protostars from the Ophiuchus
4
The InstitutePhysicalandAtacama
ChemicalResearch(RIKEN), 2-1 Hirosawa,Wako-shi,
Saitama 351-0198,
molecularof
cloudwith theLarge
Millimeter/submillimeter
Array (ALMA).
The continuum
at 0.87 mm Japanand molecular tran5
Max-Planck-Institut
Physik,Giessenbachstraße
1, at85748,
Garching
bei München,sitions from C17 O,fürC34extraterrestrischeS, H13 CO+ , CH3 OH,
SO2 , andC2 H were observedhigh angularresolution(000. 4, ⇠60 Germany
au diameter) towards
6
each source.
The spectrally
and spatiallyreveal the
kinematics
and theJapan
spatial distribution of each species. Moreover,
Departmentof Physics,
The University
ofresolved
Tokyo, maps
Bunkyo-ku,
Tokyo
113-0033,
1

ph.SR] 30 Apr 2019

Context. The structure and composition of emerging planetary systems are likely strongly influenced by their natal environment

disc and stellar masses are estimated from the continuum flux and position-velocity diagrams, respectively.
May 1,Results.
2019 Six of the sources show disc-like structures in C17 O, C34 S , or H13 CO+ emission. Towards the more luminous sources,
compact emission and large line widths are seen for transitions of SO2 that probe warm gas (Eu ⇠200 K). In contrast, C17 O emission
is detected towards the least evolved and less luminous systems. No emission of CH3 OH is detected towards any of the continuum
peaks, indicating an absence of warm CH3 OH gas towards thesesources.
ABSTRACT
Conclusions. A trend of increasing stellar mass is observed as the envelope mass decreases. In addition, a power-law relation is seen
7
1
betweenthestellar
mass
and
the
bolometricluminosity,
corresponding
to
a
mass
accretion
rate
of
(2.4
±
0.6)
⇥
10
M
year
for
Context. The structure and composition of emerging planetary systems
arelikelystrongly
influenced
by
their
natal
environment
8
7
1
the
Class
I
sources,withaminimumandmaximum
value
of
7.5
⇥
10
and
7.6
⇥
10
M
year
, respectively.
Thisandmass
accretion
within the protoplanetary disc at the time when the star is still gaining mass. It is therefore essential
to identify
study
the physicalrate is lower than the expected value if the accretion is constant in time and rather points to a scenario of accretion occurring in bursts.
processes at play in the gas and dustof the material that is inherited
17 close to young protostars and investigate the chemical composition
17
The di↵erentiation between C O and SO2 suggests that they trace di↵erent physical components: C O traces the densest and colder
from theparental
cloud.
regions of the disc-envelope system, while SO2 may be associated with regions of higher temperature, such as accretion shocks. The
Aims. The
paper is to explore and compare the physical and chemical structure of Class I low-mass protostellar sources
lackpurposeof warm ofCHthis3 OH emission suggests that there is no hot-core-like region around any of the sources and that the CH3 OH column
on protoplanetary
disc overscales.
density averaged
the disc is low. Finally, the combination of bolometric temperature and luminosity may indicate an evolutionary
Methods.
We
study of theduring
dust andgas
emission
trend
ofpresentchemicala composition
these
early
stages. towards a representative sample of 12 Class I protostars from the Ophiuchus

molecular cloud with the Atacama Large Millimeter/submillimeter Array (ALMA). The continuum athttps://arxiv.org/pdf/1904.13161.pdf
0.87 mm and molecular tranKey words.
ISM:
17
34 molecules13+ – stars: formation – protoplanetary discs – astrochemistry – Individual: Ophiuchus
sitions from C O, C S, H CO , CH3 OH, SO2 , and C2 H were observed at high angular resolution (000. 4, ⇠60 au diameter) towards!14kinematics and the spatial distribution of each species. Moreover,each source. The spectrally and spatially resolved maps reveal themithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
4 Millimeter / Submillimeter Array, Joint ALMA Observatory, Alonso de Córdova 3107, Vitacura 763-0355, Santiago, Chileargekalisches Institut und Universitätssternwarte, Friedrich-Schiller-Universität Jena, Schillergäßchen 2-3, 07745 Jena, Germanyk Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany
nto de Ciencias Fisicas, Facultad de Ciencias Exactas, Universidad Andres Bello. Av. Fernandez Concha 700, Las Condes, Santiago, Chile.

Sub-millimeter non-contaminated detection of the disk
around TWA 7 by ALMA.
1,2
?
1,2
3
1,2
4
A. Bayo , J. Olofsson , L. Matrà J. C. Beamı́n , J. Gallardo ,

4,2
5
1,2
1,2
6
I. de Gregorio-Monsalvo , M. Booth , C. Zamora , D. Iglesias , Th. Henning ,XX. Received YYY; in original form ZZZastro-ph.SR] 20 Apr 2019

1,2
7,2
M. R. Schreiber and C. Cáceres

1 Instituto de Fı́sica y Astronomı́a, Facultad de Ciencias, Universidad de Valparaı́so, Av. Gran Bretaña 1111, Valparaı́so, Chile

ABSTRACT

2 Núcleo Milenio Formación Planetaria - NPF, Universidad de Valparaı́so, Av. Gran Bretaña 1111, Valparaı́so, Chile

Debris disks can be seen as the left-overs of giant planet formation and the possinurseries of rocky planets. While M-type stars out-number more massive stars we
4 Atacamable
Large Millimeter / Submillimeter Array, Joint ALMA Observatory, Alonso de Córdova 3107, Vitacura 763-0355, Santiago, Chile
5 Astrophysikalisches
know very
littlethetime evolutionof their circumstellar
disksäßchen
at agesolderJena, Germany
Institutundabout
Universitätssternwarte,Friedrich-Schiller-Universit
ät Jena, Schillerg
2-3, 07745
6 Max Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany
than ⇠ 10 Myr. Sub-millimeter observations are best to provide first order estimates
7 Departamento de Ciencias Fisicas, Facultad de Ciencias Exactas, Universidad Andres Bello. Av. Fernandez Concha 700, Las Condes, Santiago, Chof the available mass reservoir and thus better constrain the evolution of such disks.
Here, we present ALMA Cycle 3 Band 7 observations of the debris disk around the M2
star
TWA
7,
which
had
been
postulatedtoharbortwo
spatially
separated
dust
belts,
Accepted XXX. Received YYY; in original form ZZZ
based on unresolved far-infrared and sub-millimeter data. We show that most of theemission at wavelengths longer than ⇠ 300 µm is in fact arising from a contaminantsource, most likely ABSTRACTa sub-mm galaxy, located at about 6.600 East of TWA 7 (in 2016).
Debrisdisks canofbe
seen
as thedata
left-overs
of us
giant
formation
Fortunately, the highresolution
ourALMA
allowsto planet
disentangle
the andcon-the possinurseries
rockyplanets.
While M-typestars out-number
massivetaminant emission ble
fromthat ofof thedisc
and reporta significant
detection moreof thedisk stars weknow
the time
evolution
circumstellar
at ages older
in the sub-millimeter
forvery
the little
first abouttime witha fluxdensityofoftheir
2.1±0.4
mJy at disks
870 µm.
than ⇠ 10 Myr. Sub-millimeter observations are best to provide first order estimates
With this detection,
we
show
that
the
SED
can
be
reproduced
withasingledust
belt.
of the available mass reservoir and thus better constrain the evolution of such disks.
3 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA

Here,
we present ALMA
3 Band 7 –observations
the debris
disk around the M2
Key words: stars:
circumstellar
matterCycle– low-massindividual:ofTWA
7https://arxiv.org/pdf/1806.09252.pdf
star TWA 7, which had been
postulated to harbor two spatially separated dust belts,!15
based on unresolved far-infrared and sub-millimeter data. We show that most of theA Survey of C2H, HCN, and C O in Protoplanetary Disks
5

Jennifer B. Bergner1, Karin I. Öberg2, Edwin A. Bergin3, Ryan A. Loomis4 , Jamila Pegues2, and Chunhua Qi2
1
18
Harvard
University,
DepartmentofChemistryandChemical
Biology,Cambridge, MA 02138, USADisksA Survey of
C
H,
HCN,
and
C
O
in
Protoplanetary22Harvard-Smithsonian
Center for Astrophysics, Cambridge, MA 02138, USA
3

University of MIchigan Department of Astronomy, Ann Arbor, MI 48109, USA
1
2
3
4
2
2
4
National Radio
Astronomical
Observatory,
Charlottesville,
VA 22903, USA
Jennifer B. Bergner , Karin I. Öberg
, EdwinA. Bergin, RyanA. Loomis, Jamila Pegues , and Chunhua Qi
1Received2018 October
31; revised
March 25;
2019
March 26;
published MA
2019 02138,
April 30USA
Harvard
University,
Departmentof2019Chemistry
andaccepted
Chemical
Biology,Cambridge,
2

Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA
3
University of MIchigan Departmentof Astronomy, Ann Arbor, MI 48109, USA
Abstract
4
National Radio Astronomical Observatory, Charlottesville, VA 22903, USA
Molecular Received
lines observed
towarddisks25;
carry
information
about26;physicalchemicalprocesses
2018 October
31;protoplanetary
revised 2019 March
accepted
2019 March
publishedand
2019
April
30
18

associated with planet formation. We present ALMA Band 6 observations of C2H, HCN, and C O in a sample of 14
disks spanning a range of ages, stellar luminosities, and stellar masses. Using C2H and HCN hyperﬁne structure
13
Abstract
optical depth, excitation temperature, and column density
ﬁtting and HCN/H CN isotopologue analysis, we extract
radial lines
proﬁlesobserved
for a subset
of disks.
C2H is marginallythick (τ∼1–5)
andphysicalHCN is quite
optically thick
Molecular
towardprotoplanetarydisks optically
carry informationabout
and chemical
processes18(τ∼5–10)
in
the
inner
200
au.
The
extracted
temperaturesofbothmolecules
arelow(10–30K),
indicative
either of 14
associated with planet formation. We present ALMA Band 6 observations of C2H, HCN, and C O in aofsample
subthermal
emission
from
the
warm
disk
atmosphereorsubstantial
beam
dilutionduetochemical
substructure.
We
disks spanning a range of ages, stellar luminosities, and stellar masses. Using C2H and HCN hyperﬁne structure
explore the origins
13 of C2H morphological diversity in our sample using a series of toy disk models and ﬁnd that diskCN
isotopologue
analysis,
weextract
opticaldepth,
excitation
temperature,andcolumndensityﬁtting dependentand HCN/H
overlap between regions with high UV ﬂuxes and high atomic carbon abundances can explain a wide range
radial of
proﬁles
for a subset
disks.
C2Hversus
is marginally
optically
thick ringless(τ∼1–5)
and HCNis quite
C2H emission
featuresof(e.g.,
compact
extended andringed versus
emission).
We explore
the opticallychemical thick
18 temperatures of both molecules are low (10–30 K), indicative of either(τ∼5–10)
in
the
inner
200
au.
The
extracted
relationship between C2H, HCN, and C O and ﬁnd a positive correlation between C2H and HCN ﬂuxes but no18
subthermal
emission
from
the
warm
disk
atmosphereor substantial
beam dilutionduechemical
substructure.
relationship between C2H or HCN with C O ﬂuxes. We
also see no evidence
that C2H
andtoHCN
are enhancedwith We
disk
C2H ofandC2HCN
seem to sharediversity
a commonhowever,morework ofremains
to elucidate
the chemical
exploretheage.
origins
H morphologicalin driver;
our sample
using
a series
toy diskmodels andﬁnd that diskrelationshipthesemolecules
underlying
evolutionof C, N,carbon
and O abundanceschemistries incan
disks.
dependent
overlapbetween
betweenregions
withandhightheUV
ﬂuxes andhigh atomic
explain a wide rangeof C2HKeyemission(e.g., compact
versus extended
and ringed
versus ringless emission). We explore the chemicalwords: features
astrochemistry– ISM: molecules– protoplanetarydisks
18
relationshipbetweenC2H,ﬁgure
HCN,
Supporting
material:
setand C 18O and ﬁnd a positive correlation between C2H and HCN ﬂuxes but norelationship between C2H or HCN with C O ﬂuxes. We also see no evidence that C2H and HCN are enhanced withhttps://iopscience.iop.org/article/10.3847/1538-4357/ab141e/pdf
disk age. C2H and HCN seem to share a common driver; however,more work remains to elucidate the chemical
relationship between these molecules and the underlying evolution of C, N, and O chemistries in disks.
!16
Key words: astrochemistry–
ISM:
molecules–
protoplanetarydisks
1. Introduction
There
is compelling evidence that the mechanism underlying

6

esearch School of Astronomy and Astrophysics, Australian National University, Canberra, 2611 ACT, Australia
epartment of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA
strophysics Group, School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
epartment of Astronomy, The University of Texas at Austin, Austin, TX 78712, USA
entre for Astrophysics and Supercomputing, Swinburne1‹
University of Technology, Hawthorn, VIC1‹
3122, Australia

ded from https://academic.oup.com/mnras/article-abstract/486/3/3721/5472910 by National Astrono

Matthew T. Agnew and Sarah T. Maddison

Tiny grains shining bright in the gaps of Herbig Ae transitional discs

Eloise K. Birchall , Michael J. Ireland , Christoph Federrath, John D. Monnier,3
3
4
4
Stefan Kraus, Matthew Willson, Adam L. Kraus, Aaron Rizzuto,
cepted 2019 April 11. Received 2019 April 10; in originalform 2018 April 5
55Matthew T. Agnew and Sarah T. Maddison
1 Research School of Astronomy and Astrophysics, Australian National University, Canberra, 2611 ACT, Australia
2 Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA

B S TofR Physics,
A C T University of Exeter, Stocker Road, Exeter EX4 4QL, UK
3 Astrophysics Group,ASchool2

Downloaded from https://academic.oup.com/mnras/article-abstract/486/3/3721/5

1This work presents a study of two Herbig Ae transitional discs, Oph IRS 48 and HD 169142;
5 Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
which both have reported rings in their dust density distributions. We use Keck-II/NIRC2
adaptive optics imaging observations in the L′ filter (3.8 µm) to probe the regions of thesediscs inwards of ∼ 20 au from the star. We introduce our method for investigating theseAccepted 2019 April 11. Received 2019 April 10; in original form 2018 April 5transitional discs, which takes a forward modelling approach: making a model of the disc(using the Monte Carlo radiative transfer code RADMC3D), convolving it with point spreadfunctions of calibrator stars, and comparing the convolved models with the observational data.
ABSTRACTThe disc surface density parameters are explored with a Monte Carlo Markov Chain technique.
This work presents a study of two Herbig Ae transitional discs, Oph IRS 48 and HD 169142;
Our analysis recovers emission from both of the discs interior to the well-known optically
which
both
have
reported
rings
in
their
dust
density
distributions.
We
use
Keck-II/NIRC2
thick walls, modelled as a ring of emission at ∼ 15 au in Oph′ IRS 48, and ∼ 7 au for HD
filter
(3.8
µm)
to
probe
the
regionsof
these
adaptive
opticsimaging
observations
intheL
169142, and identifies asymmetries in both discs. Given the brightness of the near-symmetricdiscs
inwards
of
∼
20
au
from
the
star.
We
introduce
ourmethodforinvestigating
theserings compared to the reported companion candidates, we suggest that the reported companiontransitional
whichasymmetrictakes a forward
modelling
approach: making a model of the disccandidates can beinterpreteddiscs,
as slightly
disc emission
or illumination.
(using the Monte Carlo radiative transfer code RADMC3D), convolving it with point spread
Key words: protoplanetary– stars:
individual:
Oph IRSand HD 169142
radiativefunctions of discs
calibrator
stars,and comparing
the48convolved
models–with
the observational data.
transfer.
https://ui.adsabs.harvard.edu/abs/2019MNRAS.486.3721B/abstract
The disc surface density parameters are
explored with a Monte Carlo Markov Chain technique.
Our analysis recovers emission
from both of the discs interior to the well-known optically!17
4 Department of Astronomy, The University of Texas at Austin, Austin, TX 78712, USA

:1904.01429v1 [astro-ph.GA] 2 Apr 201

8

1 School of Astronomy and Space Science, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, China
2 Dept. of Astronomy, University of Virginia, Charlottesville, Virginia 22904, USA

MULTI-LINE OBSERVATIONS OF MOLECULAR BULLETS IN A HIGH-MASS PROTOSTAR

3 Dept. of Astronomy, University of Florida, Gainesville, Florida 32611, USA

4 Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, Nanjing 210023, China
5 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, U.S.A.
6 Max-Planck-Institut
1, 2, 3
1, 4
für Radioastronomie,
Auf dem Hügel5 69, 53121 Bonn, Germany

Yu Cheng,

Keping Qiu,

Qizhou Zhang, Friedrich Wyrowski,6 Karl Menten,6 and Rolf Güsten6
ABSTRACT

We present Submillimeter Array (SMA) observations in the CO J = 3–2, SiO J = 5–4 and 8–7, and SO 98 –87
1 School of Astronomy and Space Science, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, Chinalines, as well as Atacama Pathfinder EXperiment (APEX) observations in the CO J = 6–5 line, of an extremely
2 Dept. of Astronomy, University of Virginia, Charlottesville, Virginia 22904, USA
high-velocity and jet-like outflow in high-mass star-forming region HH 80–81. The outflow is known to contain two
3 Dept. of Astronomy, University of Florida, Gainesville, Florida 32611, USA
prominent molecular bullets, namely B1 and B2, discovered from our previous SMA CO J = 2–1 observations. While
4 Key Laboratory
B1 is detected
in allAstronomy
the CO, SiO,
and SO lines,(Nanjing
B2 is only
detected Ministry
in CO lines.
The CONanjing
3–2/2–1210023,
line ratio
inof Modernand Astrophysics
University),of Education,
China
5 Harvard-Smithsonian
B1 is clearly greaterthat in B2. 60
WeGarden
performStreet,a largevelocity gradientanalysisof the CO lines and derive a
Centerthan
for Astrophysics,
Cambridge,
MA 02138,
U.S.A.
temperature of
K for B1 andK for 69,
B2.53121
Takinginto Germany
account the diﬀerences in the velocity, distance
6 Max-Planck-Institutfür70–210
Radioastronomie,
Auf20–50
dem Hügel
Bonn,from the central source, excitation conditions, and chemistry between the two bullets, we suggest that the bullets are
better explained by direct ejections from the innermost vicinity of the central high-mass protostar, and that we are
ABSTRACT
more likely observing the molecular component of a primary wind rather than entrained or swept-up material from
We present
Submillimeter(SMA)
in the CO
J = 3–2,
J = 5–4bullets
and 8–7,
andanSO 98 –87
the ambient
cloud. TheseArrayfindings
furtherobservations
support our previous
suggestions
that SiO
the molecular
indicateaccretion in EXperiment
the high-mass starformation
process.
lines, asepisodic,
well asdisk-mediatedAtacama Pathfinder(APEX)
observationsin the CO J = 6–5 line, of an extremely

high-velocity and jet-like outflow in high-mass star-forming region HH 80–81. The outflow is known to contain two
Keywords:
ISM:
individual
objects(HH
80–81)
—
ISM:
jets
and
outflows—
stars:
formation—stars:
prominent molecular bullets, namely B1 and B2, discovered from our previous SMA CO J = 2–1 observations. Whilemassive
B1 is detected in all the CO, SiO, and SO lines, B2 is only detected in CO lines. The CO 3–2/2–1 line ratio in
B1 is clearly greater than that in B2. We perform a large velocity gradient analysis
of
the
CO
lines
and
deriveahttps://arxiv.org/pdf/1904.01429.pdf
temperature of 70–210 K for B1 and 20–50 K for B2. Taking into account the diﬀerences in the velocity, distance!18
from the central source, excitation conditions, and chemistry between the two bullets, we suggest that the bullets are

10

Bok globule CB 17: polarization, extinction and distanced 2019 April 22. Received 2019 April 21; in original form 2018 December 27

G. B. Choudhury,

1‹

1

A. Barman, H. S. Das

1 Department of Physics, Assam University, Silchar 788011, India

ABSTRACT

2 Department of Physics, Gauhati University, Guwahati 781014, India

1‹

2‹

and B. J. Medhi

wnloaded from https://academic.oup.com/mnras/article-abstract/487/1/475/5498819 by Nation

ment of Physics, Gauhati University, Guwahati 781014, India

In this article, the results obtained from a polarimetric study of Bok globule CB 17 in both
optical and submillimetre wavelengths are presented. Optical polarimetric observations in the
R band (λ = 630 nm, "λ = 120 nm) were conducted with the 1.04-m Sampurnanand Telescope,
Accepted 2019 April 22. Received 2019 April 21; in original form 2018 December 27
Aryabhatta Research Institute of observational sciencES (ARIES), in Nainital, India on 2016
March 9, while submillimetre polarimetric data are taken from the Submillimetre CommonUser bolometer array POLarimeterdata archive, which has been reanalysed.
A B S T(SCUPOL)
RACT
andarticle,
Photometric
Imaging
Receiver500-µmstudy
dust of Bok globule CB 17 in
The contours of Herschel1 Spectral
In thisthe results
obtainedfrom(SPIRE)
a polarimetriccontinuum emission of CB 17 (typicallya cometary-shaped
globule) areareoverlaid
on theOptical
Digitalpolarimetric observations in
optical andsubmillimetre wavelengths
presented.
Sky Survey (DSS) image of CBR17
along
with
vectors(opticaland submm).
The
band
(λ =
630polarization
nm, "λ = 120nm) were
conducted
with the1.04-m Sampurnanand Telesc
magnetic field strength at the coreof the globule
is estimated99 µG. UsingsciencES
near-infrared
Aryabhatta
Research
Institutetoofbeobservational(ARIES), in Nainital, India on 2
photometric technique and GaiaMarchdata, thedistance
to CB 17 ispolarimetricfound to be data
253 ±pc. The9, while
submillimetre
are43takenfrom the Submillimetre Comm
correlation between the various Userquantitiesof the globule
is also studied.
It is observed
the which has been reanaly
bolometerarray POLarimeter(SCUPOL)data thatarchive,magnetic field in the cloud core as
revealedbyof
polarizationof the submillimetre
Spectral and Photometric
Imaging Receiver (SPIRE) 500-µm
The
contours
Herschel1 measurements
dust emission is found to be almostalignedemission
along theofminorof the globule,which fits thecontinuum
CB 17axis(typicallya cometary-shaped
globule) are overlaid on the Di
magnetically regulated star formation
model.
A misalignment
magnetic
Sky Survey(DSS)
image of CB between
17 along core-scalewith polarization
vectors (optical and submm).
field direction and molecular outflow
directionis also found.
magnetic
field strength
at the core of the globule is estimated to be 99 µG. Using near-infr
techniqueand–Gaia
the distance
Key words: polarization – ISM:photometricclouds – dust,
extinction
ISM:data,
magnetic
fields. to CB 17 is found to be 253 ± 43 pc.
correlation between thehttps://ui.adsabs.harvard.edu/abs/2019MNRAS.487..475C/abstract
various quantities of the globule is also studied. It is observed tha
magnetic field in the cloud core as revealed by polarization measurements of the submillim!19
dust emission is found to be almost aligned along the minor axis of the globule, which fits© 2019.
The American Astronomical Society. All rights reserved.
2

11

Nobeyama Radio Observatory, National Astronomical Observatory of Japan, National Institutes of Natural Sciences, Nobeyama, Minamimaki, Minamisaku,
Nagano 384-1305, Japan
3
Max-Planck-Institut für Extraterrestrische Physik, D-85748 Garching, Germany
4
Observatorio Astronómico Nacional (IGN), Alfonso XII 3, E-28014 Madrid, Spain
5
Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
6
SOFIA Science Center, USRA, NASA Ames Research Center, MS-12 N232, Moffett Field, CA 94035, USA
7
Indian Institute of Astrophysics, Koramangala, Bangalore 560034, India
8
1 Science Education, Kongju
1,9 National University, 56 1,92 Chungcheongnam-do332588, Republic of Korea
4
DepartmentofEarth
Gongjudaehak-ro,
Gongju-si,
Eun Jung Chung, Chang Won Lee, Shinyoung Kim, Gwanjeong Kim , Paola Caselli , Mario Tafalla ,9Universityof Science and Technology,
Korea 1(UST), 217, Gajeong-ro, Yuseong-gu,
Daejeon, 34113,1 Republic of Korea
5
6
7
1,8
Philip C. Myers Received, Archana, Tie Liu
, Maheswar, Miryang, Kyoung
Hee Kim,2018Soam
July 15; revised
2019 March
3; acceptedGopinathan
2019 March 22;
published Kim
2019 May
31

TRAO Survey of Nearby Filamentary Molecular Clouds, the Universal Nursery of Stars(TRAO FUNS). I. Dynamics and Chemistry of L1478 in the California Molecular Cloud
Woojin Kwon

1,9

1

1

, Hyunwoo Kang , and Changhoon Lee
1
Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of Korea
2
Abstract
Nobeyama Radio Observatory, National Astronomical Observatory of Japan,
National Institutes of Natural Sciences, Nobeyama, Minamimaki, Minamisaku,
Nagano384-1305,Japan“TRAO FUNS” is a projecttosurveythe
GouldBelt’scloudsinmolecular lines. This paper presents its ﬁrst results on
3
Max-Planck-Institut für Extraterrestrische Physik, D-85748 Garching, Germany
the central region of the4 Observatorio
California
molecular
cloud,
L1478.
We
performed
on-the-ﬂy
mapping
observations
using
the
Astronómico Nacional (IGN), Alfonso XII 3, E-28014 Madrid, Spain
5
Taeduk Radio Astronomy
ObservatoryCenter
14 mforsingle-dishtelescopeequippedwith a 16 MA
multibeamarray covering a ∼1.0
Harvard-Smithsonian
Astrophysics,
60 Garden
Street, Cambridge,
02138, USA
18O (1–0), mainly tracing low-density clouds, and a ∼460 square arcminute6
square degreearea ofthis region
using CSOFIA
Science
Center, USRA,
NASA
Ames Research Center, MS-12 N232, Moffett Field, CA 94035, USA
7+
IndianInstituteof Astrophysics,
Koramangala,Bangalore
560034,
India
area
using
,
mainlytracing
dense
cores.
and
were
also
used simultaneously to map a
N
H
(
1
–
0
)
CS
(
2
–
1
)
SO
(
3
–
2
)
2
2
1
8
Department
Earth Science
Education,
KongjuNational We
University,
56 Gongjudaehak-ro,
Gongju-si,
Chungcheongnam-do
32588,
Republicof Korea∼440 ofsquarearcminute
area
of
this
region.
identiﬁed
10
ﬁlaments
byapplying
thedendrogram
techniquetothe9
University of Science and Technology,
Korea (UST), 217, Gajeong-ro, Yuseong-gu, Daejeon, 34113, Republic of Korea
18+
C O data cube and8 dense N2 H 15;cores
using FELLWALKER. Basic physical properties of ﬁlaments such as mass,
Received 2018 Julyrevised 2019 March 3; accepted 2019 March 22; published 2019 May 31
length, width, velocity ﬁeld, and velocity dispersion are derived. It is found that L1478 consists of several ﬁlaments withslightly different velocities. Particularly, the ﬁlaments that are supercritical are found to contain dense cores detected in
Abstract+
N2 H . A comparison of nonthermal velocity dispersions derived from C18O and N2 H+ for the ﬁlaments and dense cores“TRAO
is aofprojectto survey
the Gould
Belt’ssimilar
clouds tointhosemolecularThis paper
presents
its ﬁrst
resultson
indicatesFUNS”
that somethe dense
cores sharekinematicsof thelines.
surroundingﬁlaments,
while
severaldense
thecentralofkinematics
the California
cloud,
L1478. ThisWe performed
on-the-ﬂy
mapping
observations
using
the
cores
have region
different
frommolecular
those of theirﬁlaments.
suggests thatthe formation
mechanismof dense
cores
TaedukRadio canAstronomy
Observatory
14 m ﬁlaments
single-dishdepending
telescope on
equippedwith a 16 multibeamarray covering a ∼1.0
and ﬁlaments
be different
in individual
their morphologies
and environments.
square degree area of this region using C18O (1–0), mainly tracing low-density clouds, and a ∼460 square arcminute
Key words: ISM:
clouds – ISM: kinematics and dynamics – ISM: structure – stars: formation+
area using N2 H (1–0), mainly tracing dense cores. CS (2–1) and SO (32 –21) were also used simultaneously to map a∼440 square arcminute area of this region. We identiﬁed 10 ﬁlaments by applying the dendrogram technique to the+ cores using FELLWALKER. Basic
C18O data cube1.and
N
H
8
dense
physicalpropertiesof theﬁlaments
as mass,
Introduction2
Many https://iopscience.iop.org/article/10.3847/1538-4357/ab12d1/pdf
youngstellargroups innearbysuch
molecular
clouds arelength, width, velocity ﬁeld, and velocity dispersion are derived.found
It is found
that
L1478
consistsofseveralﬁlaments
withto be well associated with a hub–ﬁlament structure that
2!
0
How slightly
stars formin molecular
clouds is oneof the key
different
velocities. Particularly,
the ﬁlamentsthat are supercritical are found to contain dense cores detected in