Star Formation Newsletter#325 33-41
Yusuke Aso (KASI)

© 2019. The American Astronomical Society. All rights reserved.

Mass Assembly of Stellar Systems and Their Evolution with the SMA (MASSES)—Full
Data Release
Ian W. Stephens1 , Tyler L. Bourke1,2, Michael M. Dunham1,3 , Philip C. Myers1 , Riwaj Pokhrel4 , John J. Tobin5 ,Héctor G. Arce6 , Sarah I. Sadavoy1 , Eduard I. Vorobyov7,8 , Jaime E. Pineda9 , Stella S. R. Offner10 , Katherine I. Lee1,
Lars E. Kristensen11, Jes K. Jørgensen11 , Mark A. Gurwell1 , and Alyssa A. Goodman1
1

•
•
•
•
•

Center for Astrophysics, Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA; ian.stephens@cfa.harvard.edu
Table 3
2
Other SK11
SWARM9FT,
Lines UK
Detected toward Some Pointings
SKA Organization, Jodrell Bank, Lower Withington, Macclesﬁeld, Cheshire
3
Department of Physics, State University of New York at Fredonia, 280 Central
NY 14063, USA
Tracer Ave, Fredonia,
Transition
Frequency
4
Department of Astronomy, University of Massachusetts, Amherst, MA 01003, USA(GHz)
5National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville,
VAJN22903,
=55−4USA
215.22065SO
4
6+Department of Astronomy, Yale University, New Haven,
06520, USA
DCOCT
J=3−2
216.11258
7
J=5−4Research Institute of Physics, Southern Federal University, Stachki Ave.SiO
194, Rostov-on-Don,
344090, Russia217.10498
8DCNJ=3−2
217.23854
University of Vienna, Department of Astrophysics, Vienna, A-1180, Austria
9c-C3H260,6–51,5
217.82215
Max-Planck-Institut für extraterrestrische Physik, D-85748
Garching, Germanyc-C3H261,6–50,5
217.82215
10Department of Astronomy, The University of Texas at Austin,
Austin,TX
78712,
USA
JKa, Kb  30,3  2 0,2
H2CO
218.22219
11
Niels Bohr Institute and Center for Star and Planet Formation, Copenhagen University,
DK-1350
Copenhagen
K.,
Denmark
JKa, Kb  32,2  2 2,1
H2CO
218.47563
18
+
13
+
+
Received 2019 August 13; revised 2019 October 15; accepted 2019 October
27218.76007
JKa, Kb2019
 32,1 November 2 2,0H2CO25; publishedEu(K)

いろいろな分⼦雲から明るいものだけではなく、同じ領域を全て。
430 pc以内であればペルセウスに原⼦星が⼀番多い。VANDAMで連星率も。
SMA、74原⼦星、30" (9000 au)から1" (300 au)。
CO 2-1, CO 3-2, 13CO 2-1, C O 2-1, N2D 3-2, H CO 4-3, HCO 4-3など。
Abstract
Stephens+18ではSUB配列だけで、地球の⾃転によるV
losの⽇ごとの変化の計
We present and release the full data set for the Mass Assembly of Stellar Systems and their Evolution with the
算に問題もあった。⾮負cleanでフラックスも⾼かった。
SMA (MASSES) survey. This survey used the Submillimeter Array (SMA) to image the 74 known protostars
within the Perseus molecular cloud. The SMA was used in two array conﬁgurations to capture outﬂows for scales• 1.3 mm, 850 µmで0.0075
Mau)sunMdown>30″ (>9000
and, to0.032
probe scales∼1″ (∼300 au). The protostars were observed with the 1.3 mm andsuntoの感度。
SO

JN=65−54219.94944

34

JN=98−87
J=28−27
J=4−3
JN=78−67
J=7−6
J=4−3
JN=88−77J=4−3
JN=98−87
13+
J=5/2−3/2
F=5/2−5/2
F=3/2−3/2
F=7/2−5/2
18
F=3/2−1/2
F=5/2−3/2
J=7/2−5/2
F=7/2−5/2
F=9/2−7/2
F=5/2−3/2
F=5/2−5/2
F=7/2−7/2
J=5−4
J=4−3
J=5−4

339.85763
340.44927
340.63069
340.71416
342.88285
344.20032
344.31061
345.33977
346.52848

SO
OCS
HC18O+
SO
CS
HC15N
SO
H13CN
SO
CN

44.1
20.7
31.3
20.9
38.6
38.6
21.0
68.1
68.1
35.0

77.3
220.6
40.9
64.9
65.8
41.3
71.0
41.4
62.1
32.6

850 μm receivers simultaneously to detect continuum at both wavelengths and molecular line emission fromCO(2–1), 13CO(2–1), C18O(2–1), N2D+(3–2), CO(3–2), HCO+(4–3), and H CO (4–3). Some of the340.00813
observations also used the SMA’s recently upgraded correlator, SWARM, whose broader bandwidthallowed
340.01963+
340.03155a andfor several more spectral lines to be observed (e.g., SO, H2CO, DCO , DCN, CS, CN). Of the main continuum
340.03541
width isspectral tracers observed, 84% of the images and cubes had emission detected. The median C O(2–1) line
340.03541−1∼1.0 km s , which is slightly higher than those measured with single-dishCN telescopes at scales of 3000–20,000 au. 32.7
340.24777ais the
Of the 74 targets, six are suggested to be ﬁrst hydrostatic core candidates, and we suggest that L1451-mm
340.24777
best candidate. We question a previous continuum detection toward L1448IRS2E. In the SVS13
system,340.24854
SVS13A certainly appears to be the most evolved source, while SVS13C appears to be hotter and more
evolved340.26177
340.26495
than SVS13B. The MASSES survey is the largest publicly available interferometriccontinuum and spectralline 51.9
DCO+
360.16978
protostellar survey to date, and is largely unbiased as it only targets protostars
inPerseus.
Allvisibility(uv) data 43.5
HNC
362.63030
DCN
362.04648
52.1
and imaged data are publicly available athttps://dataverse.harvard.edu/dataverse/full_MASSES/.

• 分⼦流のサブ構造が新しく⾒つかった。

Notes.(1302);
Splatalogue (http://www.splatalogue.net/)is used forthe frequencies
Uniﬁed Astronomy Thesaurus concepts: Star formation (1569); Protostars
Surveys (1671); Stellar
jets
and upper energy levels. Other lines may also exist within the delivered(1607); Dense interstellar clouds (371); Young stellar objects (1834); Molecular
clouds(1072)
visibility data. Images of these spectral lines are only provided for targets with

1. Introduction
The formation of stars involves a complex interaction ofrelated phenomena. Gravitational collapse occurs within dense
regions of gas and dust with magnetic ﬁelds, turbulence, stellar
feedback, and rotation. Given the complexity, the balance of
these ingredients may differ signiﬁcantly from source to source.
As such, a statistical approach is necessary to understand the

For both robust weightings, the sensitivities and thedimensions of the synthesized beams for each target are given
in tables in the Appendix. Table 5 shows these for 1.3 mm, andTable 6 shows these for 850 μm observations. To keep thesample of roughly a dozen systems, they found evidence that Appendix concise, we do not include the sensitivities for theoutﬂows are
morecollimatedearlierassociatedstages withandsourcesthat the SWARM-only lines. Sensitivities and beam sizes can vary
foundthat noemission wasatobviously
throughout each of SWARM’s 16 GHz sideband, but inthe pointing (i.e.,
the tracer
was undetected
there outﬂow.
weresurroundingin envelopes
becomeswept
up withor thegeneral, the sensitivity and beams in the imaged 0.2 km s−1
interferometricartifactsfromlarge-scale
emission),
we did andnot the SWARM channels are similar to the main spectral lines imaged
The outﬂows
widen
with
time,
carvingoutawide
cavity,apply any iterative cleaning algorithm, but rather simply
i.e., C18O(2–1), N2D+(3–2),
envelope starts
toalldissipate
and lengthen
perpendicular
to the at the+ same spectral13 resolutions,cleanedpixels and channels
in the dirty
map to 3times theHCO (4–3), and H CO+(4–3). The sensitivities can be easily
dirtypicture
map noise.
clean components
were then usedwith theoutﬂow. This
is Thesupportedby simulations(e.g.,
Offner calculated by the user by opening the data cubes and measuring
map and beam to create cleaned maps via the MIRIAD
et al. 2011).dirty
Severalothermolecular
line
interferometricsurveys
the sensitivities in the line-free channels. When mapping thetask restor. Data were not self-calibrated, as we found thatat least one SWARM SUB track.
a
The delivered cube covers all of these F transitions for the given J transition.
The delivered CN cube has this rest frequency in the ﬁts header.

© 2019. The American Astronomical Society. All rights reserved.

Mass Assembly of Stellar Systems and Their Evolution with the SMA (MASSES)—Full
Data Release
Ian W. Stephens1 , Tyler L. Bourke1,2, Michael M. Dunham1,3 , Philip C. Myers1 , Riwaj Pokhrel4 , John J. Tobin5 ,Héctor G. Arce6 , Sarah I. Sadavoy1 , Eduard I. Vorobyov7,8 , Jaime E. Pineda9 , Stella S. R. Offner10 , Katherine I. Lee1,
Lars E. Kristensen11, Jes K. Jørgensen11 , Mark A. Gurwell1 , and Alyssa A. Goodman1
1

Center for Astrophysics, Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA; ian.stephens@cfa.harvard.edu
2
SKA Organization, Jodrell Bank, Lower Withington, Macclesﬁeld, Cheshire SK11 9FT, UK
3
Department of Physics, State University of New York at Fredonia, 280 Central Ave, Fredonia, NY 14063, USA
4
Department of Astronomy, University of Massachusetts, Amherst, MA 01003, USA
5
National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA
6
Department of Astronomy, Yale University, New Haven, CT 06520, USA
7
Research Institute of Physics, Southern Federal University, Stachki Ave. 194, Rostov-on-Don, 344090, Russia
8
University of Vienna, Department of Astrophysics, Vienna, A-1180, Austria
9
Max-Planck-Institut für extraterrestrische Physik, D-85748 Garching, Germany
10
Department of Astronomy, The University of Texas at Austin, Austin, TX 78712, USA
11
Niels Bohr Institute and Center for Star and Planet Formation, Copenhagen University, DK-1350 Copenhagen K., Denmark
Received 2019 August 13; revised 2019 October 15; accepted 2019 October 25; published 2019 November 27• Per-emb-4, 39, 43, 45, 59は原⼦星ではない。
• 連続波が不検出。輝線もない。
•
•
•
•
•
•

既知のファーストコア候補６個も含む。
Abstract
We present and release thefull data set for the Mass Assembly of Stellar Systems and their Evolution with the
B1-bN, B1-bSは分⼦流速度10km/s。
SMA (MASSES) survey. This survey used the Submillimeter Array (SMA) to image the 74 known protostars
within the Perseus molecular
cloud.4The
SMA was used in two array conﬁgurations to capture outﬂows for scales
L1451-mm, Per-bolo-58は1
km/s,
km/s。
>30″ (>9000 au) and to probe scales down to ∼1″ (∼300 au). The protostars were observed with the 1.3 mm and850 μm receivers
simultaneously to detect continuum at both wavelengths and molecular line emission from
L1448 IRS2E (⾼速ガス),
Per-bolo-45はVANDAMで受かってない。
CO(2–1), C O(2–1), N D (3–2), CO(3–2), HCO (4–3), and H CO (4–3). Some of theCO(2–1),
observations also used the SMA’s recently upgraded correlator, SWARM, whose broader bandwidth allowed
L1451-mmは分⼦流がコンパクトで⼀番の候補。
for several more spectral lines to be observed (e.g., SO, H CO, DCO , DCN, CS, CN). Of the main continuum and+が中⼼。収縮し始め。
tracers observed, 84% of the images and cubes had emission detected. The median C O(2–1) line width is
Per-bolo-45はN2Hspectral
13

18

2

+

+

2

13

+

+

18

−1

∼1.0 km s , which is slightly higher than those measured with single-dish telescopes at scales of 3000–20,000 au.
Of the 74 targets, six are suggested to be ﬁrst hydrostatic core candidates, and we suggest that L1451-mm is thebest candidate. We question a previous continuum detection toward L1448IRS2E. In the SVS13 system,
SVS13A certainly appears to be the most evolved source, while SVS13C appears to be hotter and more evolved
than SVS13B. The MASSES survey is the largest publicly available interferometric continuum and spectral line
protostellar survey to date, and is largely unbiased as it only targets protostars in Perseus. All visibility (uv) dataand imaged data are publicly available athttps://dataverse.harvard.edu/dataverse/full_MASSES/.

• SVS13A: N2H+なし。⼀番進化。
• SVS13C: SiO以外の輝線が最も明るい。13Cが13Bより進化。

Uniﬁed Astronomy Thesaurus concepts: Star formation (1569); Protostars (1302); Surveys (1671); Stellar jets
(1607); Dense interstellar clouds (371); Young stellar objects (1834); Molecular clouds (1072)
1. Introduction
The formation of stars involves a complex interaction ofrelated phenomena. Gravitational collapse occurs within dense
regions of gas and dust with magnetic ﬁelds, turbulence, stellar
feedback, and rotation. Given the complexity, the balance of
these ingredients may differ signiﬁcantly from source to source.
As such, a statistical approach is necessary to understand thesample of roughly a dozen systems, they found evidence that
outﬂows are more collimated at earlier stages and that thesurrounding envelopes become swept up with the outﬂow.
The outﬂows widen with time, carving out a wide cavity, and theenvelope starts to dissipate and lengthen perpendicular to theoutﬂow. This picture is supported by simulations (e.g., Offner
et al. 2011). Several other molecular line interferometric surveys

492/1/210/5670639 by KASI user on 24 February 2020

ticle-abstract/492/1/210/5670639 by KASI user on 24 February 2020

we do not model interactions between grains of different sizes andAdvance Access publication 2019 December 9
on
betweenthe dusthaveand gasphases. We
v g is the differential velocity
consequently
a differential
radial drift velocity that is nullust
only
considertheturbulent
relative
velocity
term
in
our
model,
sc orbiting a 1 M" star. Initially, we setSelf-induced
within dust
this approximation.
This lines
is oneinofprotoplanetary
the caveats of ourmodeltraps around snow
discs
han
ng the gas which
disc withapower-lawsurface
we verify to be dominantascomparedradialdrift orwe discussto
in theSection
4.2.4.
‹
the temperature
Arnaud Vericel
andJean-François
GonzalezThe
structure
is verticallyBrowniancomponents.
Moreover,
our
model
being
monodisperse,
When
aLyon
dust
particle
grows(i.e. if Vrel < Vfrag ), it doubles its
Univ
Lyon,
Univ
ClaudeBernard
1,
ENS
de
Lyon,
CNRS,
Centrede Recherche Astrophysique de Lyon UMR5574, F-69230 Saint-Genis-Laval, France
−q
ds in
(r/r
)
.
We
a radial power
law,
T
=
T
0 interactions
0
we do not model
betweengrains theof different
sizes dm
andd /dt = md /τ col , which translates
mass duringcollision time:barrier’ (Laibe, Gonzalez & Maddison 2012). Similarly to the dust

Downloaded from https://academic.oup.com/mnras/article-abstract/492/1/210/5670639 by KASI user on 24 Februa

consistent planet formation theory is the goal of both theoreticians

Downloaded from https://aolve for eight
orbits at 100 au(8000yr) toAccepted 2019in
size4.toDecemberReceived
November 26; in original
October 17
consequently
have
a differential
radialdrift2019velocity
thatformis2019null
injectanequal
numberofdust
particles,
set
withinthis approximation. This isdsone of
ρd the caveats of our model• ⼤きいダストはくっつかないし、落ちる。特殊条件（惑星や渦）ではなくself-induced。
gas
ratio
"
is
uniform
and
equal
to
0.01.
Vrel ,A B S T R A C T
(9)
=
ace
as
we
discuss in Section 4.2.4. dt•
スノーラインを超えると内側でガス圧上昇、外側でダスト⾯密度上昇。
ρDust particles need to grow efficiently from micrometre sizes to thousands of kilometres tosflly
10 µm and are able to grow or fragment
planets.
the growth of
to metre sizes being hindered by a number of
<form
Vfrag
), itWithdoubles
itsmillimetreWhen
a dustparticle
grows (i.e.
if Vρrel is
⽔のスノーラインは観測が難しい。COは理論がよくわかっていない。
thevolumedensity
the isdust
phase.
Whenwhere
oth gas and•dust
particles
are setbetweenbarriers,
the recent discovery
that dustof
evolution
able to create‘self-induced’
dustthetrapsandshows
212
A. Vericel
J. F. GonzalezdWe
promises.
The
condensation
andsublimationofvolatile
speciesatcertainlocations,called
snow
/dt
=
m
/τ
,
which
translates
mass
duringthecollision
time:
dm
d
d col(i.e. when Vrel > Vfrag ), their size evolve following
grainsfragmentd from the simulation if they cross resc .
Tablescenarios.
1. Summaryof thethatmechanisms
included in our model.
lines, are also thought to be important parts of planet formation
Given
dust
gas sound s
) to
in
size
to
!
•
3D、２相、SPH、M
=0.01
M
、M
=1
M
。
sticking
properties
changeacross
a
snow
line,
this
raisesthequestion:
how
do
snow
lines
et al. (2015):
he code and set-up, we refer the reader to disk Gonzalez
sun
*
sun
kB T
Mechanism
Includedaffecttheself-induced
dust
trap
formationmechanism?
Thequestionisparticularly
relevant
es,
cs =rametersareµm
dsgivenρind Table 2. Resolution
line in protoplanetary discs,
ρd with the multiple observations of the carbon monoxide (CO) snowdsGrowth
Yes
01.
V
,
(9)
=
since
its
effecton
dust
growthanddynamics
is
yet
to
be
understood.
In this paper,
we present
rel
=
−
V
,
(10)
V
<
V
V
>
V
Fragmentation
Yes
shown convergence
with
fewer
rel
relparticles
frag
rel
frag
where kB isdtρ
the effects of snow lines in general on the formation of self-induced
dust traps in a parameterdtρBack-reaction
Yes
s
s
and
mH theent
05; Fouchet et al. 2007; Pignatale et al.
Snow line(different Vfrags)
Yes
study, and then focus on the CO snow line. We find that for a rangeof parameters,
a dusttrap
Evaporation/condensation
Noforms
at theline
wherecase,thedust accumulates
and slowly
grows,
as foundfor the water
similartophase.
thesnowgrowthmeans thattheinitialgrain
volumeof the
dust
When
the
where
ρを変えてダスト組成変化とする。
eensolution criterion
proposedbyGonzalez
Laibe & densitywhich,d is214
VericelandtheJ. F.
No• VA.frag
2.3 Growt
snow line in a previous work. We also find that, depending onSelf-gravity
the grains’ sticking properties
loses
most
of
its
mass
duringthecollision.
Thiscorresponds
to
>
V
),
their
size
evolvefollowinggrainsfragment
(i.e.
when
V
.
imulations.
oneither
side
of
the
CO
snow
line,
it
could
be
eitherastartingorbraking
point
for
dust
growthrelfragesc
The implem
Table
2. distributions
The disc modelandusedsnow
in our simulations, with r0 = 1 au.
anddrift.
This
could
provideclues
tounderstandthelinkbetweendust
Laibe et al.
a catastrophic fragmentation event.
is represented
the Stokes
et al.by(2015):
rastoand dustGonzalez
lines in protoplanetary disc observations.
grains, i.e.
p
q
!0
T0
rin
rout
resc
of
a
io
betweenthestopping
timet
distributionsion
Key words: hydrodynamics – methods: numerical – planets and satellites:(kgformation
– (K)
m−2 )
(au)
(au)
(au)
ρd
ds
motion bet
protoplanetary discs.
=, ts /tk . In ourerian= −tk : StVrel
(10)
1
1/2
487.74
200
10
300
400
les orbital time
velocity is l
2.4 Snow lines as discontinuities in fragmentation thresholddt
ρrelativevesdensity
have smaller
al. is low and the grains
Valageas (1solutions arestudied
notdirectlyused in our simulations (the equations
a radialbeen
drift towards
the star (Weidenschilling
1977;
Nakagawa,
hasexperimentally
The fragmentation
velocity
Vfragsubsequently
treat
e path: s <which,
9/4λg . We
1 I N T RO
D U C T ImeansONsimilartothegrowth
case,
that
the
initialgrain√of dustmotionareareinstead&
Sekiya & Hayashi標準モデル。
1986). The small
grainsstronglysolved
coupleddirectly, see Section 2.2), they are
Vrel = 23&largeWurm
Wadasilicates,
water
ice,formationand hasCO2 iceto understandwhichmechanism is responsible for creating
pstein regime(Epstein
1924),
where
theOver the lastfor
few decades,
our perceptionof planetto the (Blumgas, while theonesusefulare2008;
strongly
decoupled.
In bothloses most of its mass during
the collision. This corresponds cases,to the radial drift
maximum
somewhere in the disc other than at the innerchanged significantly because of the continuous improvement inis slow. It aispressurefor intermediate-sized
育ちながら中へ、スノーラインからは分裂
where Ro i
et
al.
2009;
Güttler
et
al.
2010;
Yamamoto,&maximalWada
2014;
essed asthe resolution of protoplanetary disc observations. Additionally,grains, typically Kadono
between the millimetre
thecentimetre.
As centre of the self-induced dust trapedge.
Thisandmechanism
is at theacatastrophic
fragmentation
event.
3 and α is t
kes
the growing Musiolik
number of exoplanets
discovered
eachMusiolik
year indicates & Wurm
grains grow,2019)
they してゆっくり落ちる、pilereachandthis maximal
radial drift
velocity and areup。
mechanism.
et
al.
2016;
has
been
shown
set to 10−2 .
that planet formation is very common and diverse (Cassan et al.
rapidly accreted on to the star. This constitutes one of the obstacles
f a
rsnow
やVasfragin/ Vbarrier’を変えてみる。
seems
to be in agreement
fascinating
for planet formation,
first known
the ‘metre-sizein the(5)2012), whichtoalsobe
dependent
onwiththethedust
composition.
Fragmentation
velocities
fragout
2.2 Hydrodynamical
simulations
diversity of structures seen in recent observations of discs (Andrews
Minimum Mass Solar Nebula (MMSN)
model (Weidenschilling
Sc = (1 + S−1our(silicates)
and
tens
the
1m
et al. 2018). are
Understanding
how range
to link thesebetween
clues and buildinga s 1977;
Hayashi 1981) andlaterseveral
more generally
as the of‘radial-drift
To simulate protoplanetary disc evolution, we use our 3D, two2.4 Snow lines as discontinuities
ininfragmentationthresholdAdvance Access publication 2019 December 9

Self-induced dust traps around snow lines in protoplanetary discs
Arnaud Vericel ‹ and Jean-François Gonzalez
Univ Lyon, Univ Claude Bernard Lyon 1, ENS de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, F-69230 Saint-Genis-Laval, France

Accepted 2019 December 4. Received 2019 November 26; in original form 2019 October 17

ABSTRACTDust particles need to grow efficiently from micrometre sizes to thousands of kilometres toform planets. With the growth of millimetre to metre sizes being hindered by a number ofbarriers, the recent discovery that dust evolution is able to create ‘self-induced’ dust traps shows
promises. The condensation and sublimation of volatile species at certain locations, called snowlines, are also thought to be important parts of planet formation scenarios. Given that dust
sticking properties change across a snow line, this raises the question: how do snow lines
affect the self-induced dust trap formation mechanism? The question is particularly relevantwith the multiple observations of the carbon monoxide (CO) snow line in protoplanetary discs,
since its effect on dust growth and dynamics is yet to be understood. In this paper, we present
the effects of snow lines in general on the formation of self-induced dust traps in a parameter
study, and then focus on the CO snow line. We find that for a range of parameters, a dust trap
forms at the snow line where the dust accumulates and slowly grows, as found for the water
snow line in a previous work. We also find that, depending on the grains’ sticking properties
on either side of the CO snow line, it could be either a starting or braking point for dust growthand drift. This could provide clues to understand the link between dust distributions and snowlines in protoplanetary disc observations.
Key words: hydrodynamics – methods: numerical – planets and satellites: formation –protoplanetary discs.

1 I N T RO D U C T I O NOver the last few decades, our perception of planet formation has© 2020. The American Astronomical Society. All rights reserved.

Observations of the Orion Source I Disk and Outﬂow Interface
Melvyn Wright1 , Richard Plambeck1 , Tomoya Hirota2 , Adam Ginsburg3 , Brett McGuire3 , John Bally4 , andCiriaco Goddi52

1Radio Astronomy Lab, University of California, 501 Campbell Hall, Berkeley, CA 94720-3441, USA
Mizusawa VLBI Observatory, National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588, Japan
3
National Radio Astronomy Observatory, Charlottesville, VA 22903, USA
4
CASA, University of Colorado, 389-UCB, Boulder, CO 80309, USA
5
Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands
Received 2019 September 14; revised 2019 November 14; accepted 2019 November 16; published 2020 February 3• オリオンのKleinmann-Low Nebulaは⼀番近い⼤質量星形成領域、415 pc。
• ⼀番重いSrcIは円盤があり、豊富な化学。⼀般的か、BNとの相互作⽤のせいか。
Abstract
We imaged the continuum and molecular line emission from Orion SourceI (SrcI) with up to 30 mas (12 au) resolution• VLA 43, 99 GHz, ALMA
223, 340 GHz。塩(NaCl), H O, AlO, SiO, SiS, SO, SO 輝線。
at 43, 99, 223, and 340 GHz in an attempt to probe the structure2and chemistry of the circumstellar disk and bipolar2
Frequency
(GHz)
43
99
224
340

Beam
(arcsec, PA)
0.06×0.04, 33°
0.04×0.04, 47°
0.04×0.02, 66°
0.03×0.01, 58°

outﬂow associated with this high-mass protostar. The continuum spectral index ranges from ∼2 along the midplane ofthe diskTable
to ∼3
along the edges, consistent with dust that is optically thick in the midplane but becomes optically thin at2
the and
periphery.
Salt (NaCl)emission
is visible where the dust is optically thin; it provides a unique tracer of the velocity
Measured Sizes
Flux Densities
for SourceIﬁeld within the disk. All other molecules that we have mapped—H2O, AlO, SiO, SiS, SO, and SO2—appear to originate
Deconvolved
SizeThe base of the outﬂow is corotating
Integrated
primarily in the bipolar
outﬂow.
withFlux
the disk. SiS shows a ﬁlamentary structure(arcsec, PA)(mJy)
that is most prominent
along the edges of the outﬂow. The molecular distributions
suggest that Si and Al released from
0.099±0.002×0.057±0.002,−40°. 4±2°.710±1and AlO, and with SO and SO2 to form SiS.
dust grainsin the disk react with oxygen
derivedfrom H2O to form SiO
0.151±0.005×0.044±0.002, −37°. 8±1°. 3

58±6

UniﬁedAstronomy Thesaurus concepts: Protostars (1302); Circumstellar
disks (235); Molecular gas (1073);256±25
0.197±0.003×0.042±0.003, −37°. 3±0°. 4
Astrochemistry(75)
0.234±0.005×0.042±0.002,−37°. 4±0°. 3630±63
1. Introduction

2.1. 43 GHz

The Kleinmann–Low Nebula in Orion, at a distance of 415 pc(Menten et al. 2007; Kim et al. 2008; Kounkel et al. 2018), is thenearest interstellar cloud in which massive (M > 8 Me) stars are
forming. The two most massive stars in this region, SourceI(SrcI) and the Becklin–Neugebauer Object (BN), appear to berecoiling from one another at 35–40 km s−1 (Rodríguez et al.
2005; Gómez et al. 2008; Goddi et al. 2011b), suggesting thatthey were ejected from a multiple system via dynamical decay
approximately 500 yr ago (Bally et al. 2017). SrcI has a mass
∼15Me (Ginsburg et al. 2018), with a rotating accretion disk anda molecular outﬂow that is prominent in SiO. The disk around
SrcI has been studied as it is the closest known disk around ahigh-mass protostar (Hirota et al. 2014; Plambeck & Wright 2016;
Ginsburg et al. 2018); it is associated with SiO and H2O masers(Reid et al. 2007; Goddi et al. 2009, 2011b; Plambeck et al. 2009;
Matthews et al. 2010; Niederhofer et al. 2012; Greenhill et al.
2013). Recently, dozens of spectral lines of NaCl and KCl wereidentiﬁed in this disk (Ginsburg et al. 2019). The rich chemistry of
SrcI’s disk and outﬂow raises the question of whether this source
is a paradigm for high-mass star formation, or an anomaly born in

The spectral setup for the 43 GHz VLA observations included
16 wideband windows, each covering 116 MHz bandwidth and58 spectral channels. The VLA wideband setup is 64 channels
covering 128 MHz; the reduction script trimmed off end channels
because of analog ﬁlter rolloff. The data were self-calibrated using
a strong SiO v=1, J=1−0 maser feature at −3.5 km s−1 thatwas observed simultaneously in a narrowband window with aspectral resolution of 0.3 km s−1.
The wideband average, with a mean frequency of 42.65 GHz
and a bandwidth of 1.4 GHz, excludes four spectral windows
containing spectral line emission. We made images with thesynthesized beamwidth of 56×44 mas, and convolved to 30
and 50 mas resolution for comparison with images at 99 GHz(see below).
2.2. 99 GHz
ALMA observations at 99 GHz (Band 3; B3) on 2017 October
12 and 17 included four spectral windows, each with a bandwidthof 1.875 GHz and 960 spectral channels. The wideband averagege shows the
Hz continuumd 1400 K. The
grated over a5, 0.1, 0.2, 0.3,
volving beamndicated in the.05×0 03 in

may help toemperatures
cited levels
on of NaCln 5 km s−1
ween 99 andyers on both
5 GHz NaClthe spectral18−17 line
ween the two© 2020. The American Astronomical Society. All rights reserved.

Observations of the Orion Source I Disk and Outﬂow Interface
Melvyn Wright1 , Richard Plambeck1 , Tomoya Hirota2 , Adam Ginsburg3 , Brett McGuire3 , John Bally4 , andCiriaco Goddi52

1Radio Astronomy Lab, University of California, 501 Campbell Hall, Berkeley, CA 94720-3441, USA
Mizusawa VLBI Observatory, National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588, Japan
3
National Radio Astronomy Observatory, Charlottesville, VA 22903, USA
4
CASA, University of Colorado, 389-UCB, Boulder, CO 80309, USA
5
Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands
Received 2019 September 14; revised 2019 November 14; accepted 2019 November 16; published 2020 February 3

Abstract
We imaged the continuum and molecular line emission from Orion SourceI (SrcI) with up to 30 mas (12 au) resolution
at 43, 99, 223, and 340 GHz in an attempt to probe the structure and chemistry of the circumstellar disk and bipolar
outﬂow associated with this high-mass protostar. The continuum spectral index ranges from ∼2 along the midplane ofthe disk to ∼3 along the edges, consistent with dust that is optically thick in the midplane but becomes optically thin at
the periphery. Salt (NaCl) emission is visible where the dust is optically thin; it provides a unique tracer of the velocity
ﬁeld within the disk. All other molecules that we have mapped—H2O, AlO, SiO, SiS, SO, and SO2—appear to originate
primarily in the bipolar outﬂow. The base of the outﬂow is corotating with the disk. SiS shows a ﬁlamentary structurethat is most prominent along the edges of the outﬂow. The molecular distributions suggest that Si and Al released fromdust grains in the disk react with oxygen derived from H2O to form SiO and AlO, and with SO and SO2 to form SiS.
Uniﬁed Astronomy Thesaurus concepts: Protostars (1302); Circumstellar disks (235); Molecular gas (1073);
Astrochemistry (75)
1. Introduction

2.1. 43 GHz

The Kleinmann–Low Nebula in Orion, at a distance of 415 pc(Menten et al. 2007; Kim et al. 2008; Kounkel et al. 2018), is thenearest interstellar cloud in which massive (M > 8 Me) stars are
forming. The two most massive stars in this region, SourceI(SrcI) and the Becklin–Neugebauer Object (BN), appear to berecoiling from one another at 35–40 km s−1 (Rodríguez et al.
2005; Gómez et al. 2008; Goddi et al. 2011b), suggesting thatthey were ejected from a multiple system via dynamical decay
approximately 500 yr ago (Bally et al. 2017). SrcI has a mass
∼15Me (Ginsburg et al. 2018), with a rotating accretion disk anda molecular outﬂow that is prominent in SiO. The disk around
SrcI has been studied as it is the closest known disk around ahigh-mass protostar (Hirota et al. 2014; Plambeck & Wright 2016;
Ginsburg et al. 2018); it is associated with SiO and H2O masers(Reid et al. 2007; Goddi et al. 2009, 2011b; Plambeck et al. 2009;
Matthews et al. 2010; Niederhofer et al. 2012; Greenhill et al.
2013). Recently, dozens of spectral lines of NaCl and KCl wereidentiﬁed in this disk (Ginsburg et al. 2019). The rich chemistry of
SrcI’s disk and outﬂow raises the question of whether this source
is a paradigm for high-mass star formation, or an anomaly born in

The spectral setup for the 43 GHz VLA observations included
16 wideband windows, each covering 116 MHz bandwidth and58 spectral channels. The VLA wideband setup is 64 channels
covering 128 MHz; the reduction script trimmed off end channels
because of analog ﬁlter rolloff. The data were self-calibrated using
a strong SiO v=1, J=1−0 maser feature at −3.5 km s−1 thatwas observed simultaneously in a narrowband window with aspectral resolution of 0.3 km s−1.
The wideband average, with a mean frequency of 42.65 GHz
and a bandwidth of 1.4 GHz, excludes four spectral windows
containing spectral line emission. We made images with thesynthesized beamwidth of 56×44 mas, and convolved to 30
and 50 mas resolution for comparison with images at 99 GHz(see below).
2.2. 99 GHz
ALMA observations at 99 GHz (Band 3; B3) on 2017 October
12 and 17 included four spectral windows, each with a bandwidthof 1.875 GHz and 960 spectral channels. The wideband averageMNRAS 491, 5035–5055
1,2 (2020)
rgison,1 Tim Naylor ,1‹ S. P. Littlefair,
Cameron
P.4 M. Bell
Advance Access publication
2019 December. Williams1

1,3

doi:10.1093/mnras/stz3398

Darryl J. Sergison,1 Tim Naylor ,1‹ S. P. Littlefair,1,2 Cameron P. M. Bell
C.15D. H. Williams1
mber 1. Received 2019 December 1; in original form 2019 andAugust1 School of Physics, University of Exeter, Exeter EX4 4QL, UK

2 Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, UK

3 Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam, Germany

ABSTRACT

1,3!"#$%"&'(')*+",)-../0122&3&'(,435"6/53",2,$+&02&+.43%(7&80.+&3.29:;292<=><2<?<@@;@)8A)BCDE)60(+)"$)@9)F(8+6&!"#$%"&'(')*+",)-../0122&3&'(,435"6/53",2,$+&02&+.43%(7&80.+&3.29:;292<=><2<?<@@;@)8A)BCDE)60(+

Characterizing the i-band variability of YSOs over six orders of
University of Exeter, Exeter EX4 4QL, UK
ics and Astronomy, University of Sheffield, Sheffield S3 7RH,
UK
magnitudein time-scale
Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam, Germany

Accepted 2019 December 1. Received 2019 December 1; in original form 2019 August 15
We present an i-band photometricstudy of over 800 young stellar objects in the OB association
Cep OB3b, which samples time-scales from one minute to 10 yr. Using structure functions
OB association Cep OB3bのYSO800
A Bdecrease
S T R A C T in variability from Class I
we show that on all time-scales (τ ) there is a monotonic
We present an i-band photometric study of over 800 young個。1分から10年まで。変光はClass
stellar objects in the OB association
to Class II through the transition disc (TD) systems to Class
III, i.e. the more evolved systems
Cep OB3b, which samples time-scales from one minute が上がると減る。Class
to 10 yr. Using structure functions
Iの変光は数
variability
are less variable. The Class Is show an approximately power-law(τ 0.8 ) (τin) there
we show thatincreaseon all time-scales
is a monotonic decrease in variability from Class I
to Class
the transition
disc (TD)systems
III, i.e. the more evolved systems
分から10年まで上昇。Class
II, TD,from time-scales of a few minutes to 10 yr. The Class II,
TDs,II throughand Class
III systems
show
a to Classare less variable. The Class Is show an approximately power-law increase (τ 0.8 ) in variability
qualitatively different behaviour with most showing a power-law
increase in variability up to
IIIは回転周期まで上昇し、それfrom time-scales of a few minutes to 10 yr. The Class II, Class
TDs, and Class
III systems show aa time-scale corresponding to the rotational period of thequalitatively
star, withdifferent
little additionalvariability
behaviour with most showing a power-law increase in variability up to
以降はほぼない。Class
IIの3分の１
a time-scalecorresponding
to the rotational
period of the star,with little additional variability
beyond that time-scale. However, about a third of the ClassIIs showslower overallvariability,
beyond that time-scale. However, about a third of the Classは変光が⼩さいが10年まで増加。質IIs shows lower overall variability,
but their variability is still increasing at 10 yr. This behaviour
can be explained if all Class IIs
but their variability is still increasing at 10 yr. This behaviour can be explained if all Class IIs
have two primary components to their variability. The firstistwo
an primary
underlying
roughly
power-law
havecomponents
to theirvariability. The first 量降着率の変動による成分と星の回
is an underlying roughly power-law
variability
spectrum,
whichevidencefromtheinfraredsuggests
is driven by accretion ratevariability spectrum, which evidence from the infrared suggests is driven by accretion rate
転による成分。⻑時間変光が⽀配的
changes. The second component is approximately sinusoidal
and results from the rotation ofchanges. The second component is approximately sinusoidal
and results from the rotation of
the star. We suggest that the systems with dominant longer time-scale variability have a smaller
な系が回転成分が⼩さい。face-onに
the star. We suggest that the systems with dominant longer
time-scalevariability
havetheya smaller
rotational
modulation
either because
are seen at low inclinations or have more complex
magnetic
field geometries.
Wemorederive acomplex
new way of calculating
structure functions for large
rotational modulation either because they are seen at low
inclinationsor have
近いからか、複雑な磁場のせい。
simulated data sets (the ‘fast structure function’), based on fast Fourier transforms.
magnetic field geometries. We derive a new way of calculating structure functions for large
words:
accretion– stars: formation – stars: pre-main-sequence – stars: rotation – stars:
simulated data sets (the ‘fast structure function’), based Key
on fastFouriertransforms.

variables: T Tauri – open clusters and associations: individual: Cep OB3b.

Key words: accretion – stars: formation – stars: pre-main-sequence – stars: rotation – stars:
variables: T Tauri – open clusters and associations: individual: Cep OB3b.
1 I N T RO D U C T I O N
Accretion is a noisy process almost everywhere it occurs inastrophysics, but the resulting variability can be used to inferof being accreted on to the star. Thus, the amplitudes and timescales of the variability contain important clues to understanding
the underlying physics of young stars.
Until recently, most work on young star variability has concen-MNRAS 492, 1120–1126 (2020)

Advance Access publication 2019 December 11

doi:10.1093/mnras/stz3481

Effects of photoevaporation on protoplanetary disc ‘isochrones’
Alice Somigliana ,1‹ Claudia Toci ,2‹ Giuseppe Lodato ,1,2 Giovanni Rosotti
and Carlo F. Manara 4

3

1 Dipartimento di Fisica, Universitá degli Studi di Milano, Via Giovanni Celoria 16, I-20133 Milano, Italy
2 INAF – Osservatorio Astronomico di Brera, Via Brera 28, I-20121 Milano, Italy

3 Leiden Observatory, Leiden University, PO Box 9531, NL-2300 RA Leiden, the Netherlands

Accepted 2019 December 6. Received 2019 December 6; in original form 2019 October 14

ABSTRACT

Protoplanetary discs are the site of star and planet formation, and their evolution and consequentdispersal deeply affect the formation of planetary systems. In the standard scenario they evolveon time-scales ∼Myr due to the viscous transport of angular momentum. The analyticalself-similar solution for their evolution predicts specific disc isochrones in the accretionrate–disc mass plane. However, photoevaporation by radiation emitted by the central staris likely to dominate the gas disc dispersal of the innermost region, introducing another(shorter) time-scale for this process. In this paper, we include the effect of internal (X andEUV) photoevaporation on the disc evolution, finding numerical solutions for a population of
protoplanetary discs. Our models naturally reproduce the expected quick dispersal of the inner
region of discs when their accretion rates match the rate of photoevaporative mass loss, in linewith previous studies. We find that photoevaporation preferentially removes the lightest discs
in the sample. The net result is that, counter-intuitively, photoevaporation increases the average
disc mass in the sample, by dispersing the lightest discs. At the same time, photoevaporation
also reduces the mass accretion rate by cutting the supply of material from the outer to theinner disc. In a purely viscous framework, this would be interpreted as the result of a longer
viscous evolution, leading to an overestimate of the disc age. Our results thus show thatphotoevaporation is a necessary ingredient to include when interpreting observations of large
disc samples with measured mass accretion rates and disc masses. Photoevaporation leaves acharacteristic imprint on the shape of the isochrone. Accurate data of the accretion rate–discmass plane in the low disc mass region therefore give clues on the typical photoevaporationrate.
Key words: accretion, accretion discs – planets and satellites: formation – protoplanetary
discs.

Downloaded from https://academic.oup.com/mnras/article-abstract/492/1/1120/5673495 by KASI user on 24 Febru

4 European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei München, Germany

8 Department of Astronomical Science, School of Physical Science, SOKENDAI (The Graduate University for Advanced Studies), Osawa, Mitaka,

Investigation of Chemical Differentiation among theNGC2264 Cluster-Forming Clumps

Tokyo 181-8588, Japan
9 The University of Tokyo, Hongo, Bunkyo, Tokyo 113-0033, Japan

3 January 2020

arXiv:1912.10766v2 [astro-ph.GA] 31 Dec 2019arXiv:1912.10766v2 [astro-ph.GA] 31 D

Faculty of Social Information Studies, Otsuma Women’s University, Sanban-cho, Chiyoda, Tokyo 102-8357, Japan
7 National Astronomical Observatory of Japan (NAOJ), Osawa, Mitaka, Tokyo 181-8588, Japan

Kotomi Taniguchi,1,2,3! Adele Plunkett,4 Eric Herbst,1,2 Kazuhito Dobashi,5
Tomomi Shimoikura,6 Fumitaka Nakamura,7,8,9 Masao Saito7,8
1
Department of Astronomy, University of Virginia, Charlottesville, VA 22904, USA

2 Department of Chemistry, University of Virginia, Charlottesville, VA 22903, USA
3 Department of Physics, Faculty of Science, Gakushuin University, 1-5-1, Mejiro, Toshima, Tokyo 171-8588, Japan

ABSTRACT

4 National Radio Astronomy Observatory, 520 Edgemont Rd., Charlottesville, VA 22903, USA

We have carried out mapping observations of molecular emission lines of HC3 N andtoward two massive cluster-forming clumps, NGC2264-C and NGC2264-D,
7CH
3 OH
National
Astronomical Observatory of Japan (NAOJ), Osawa, Mitaka, Tokyo 181-8588, Japan
8usingDepartmentof Astronomical
Science,
Schoolradioof PhysicalScience, SOKENDAI(The Graduate
University
for Advanced3 OH)
Studies),inOsawa, Mitaka,
theNobeyama
45-m
telescope.
We derivean I(HC
3 N)/I(CH
Tokyo 181-8588, Japanintensity ratio map, showing a higher value at clumps including 2MASS
9tegrated
The University of Tokyo, Hongo, Bunkyo, Tokyo 113-0033, Japan
point sources at the northern part of NGC2264-D. Possible interpretations of theI(HC3 N)/I(CH3 OH) ratio are discussed. We have also observed molecular emission
lines from CCS and N2 H+ toward five positions in each clump. We investigate the3 January 2020
N(N2 H+ )/N(CCS) and N(N2 H+ )/N(HC3 N) column density ratios among the ten positions in order to test whether they can be used as chemical evolutionary indicators
ABSTRACT+ )/N(CCS) ratio shows a very high value toward a brightin these clumps. The N(N
2 H carried
We haveout mapping observationsof molecular emission lines of HC3 N and+embedded IR source (IRS1),
whereasN(Nat IRS1
compaCH3 OH toward
two themassivecluster-forming
clumps,
NGC2264-C
and is
NGC2264-D,
2 H )/N(HC3 N) ratio
using
the
Nobeyama
45-m
radio
telescope.
We
derivean
I(HCN)/I(CH
33 OH) inrable with those at the other positions. These results suggest that UV radiation
affects
tegrated intensity ratio map, showing a higher value at clumps including 2MASS
the chemistry around point
IRS1.sources
We findthat
therepart
areofpositive
correlations
between theseat thenorthern
NGC2264-D.
Possibleinterpretationsof the+ , which implies thecolumn density ratiosI(HCand3 N)/I(CHthe excitation
temperaturesofN
H
2 observed molecular emission
3 OH) ratio are discussed. We have alsolines from TheseCCS andchemical
N2 H+ toward
five positionsindicators
in each clump.
We investigatethechemical evolution of clumps.
evolutionary
likelyreflect theN(N2 H+ )/N(CCS) and N(N2 H+ )/N(HC3 N) column density ratios among the ten pocombination of evolution
along the filamentary structure and evolution of each clump.
sitions in order to test whether they can be used as chemical evolutionary indicators
5 Department of Astronomy and Earth Sciences, Tokyo Gakugei University, Nukuikitamachi, Koganei, Tokyo 184-8501, Japan
6 Faculty of Social Information Studies, Otsuma Women’s University, Sanban-cho, Chiyoda, Tokyo 102-8357, Japanin these clumps. The N(N H+ )/N(CCS) ratio shows a very high value toward a bright2+
Key words: astrochemistry– ISM:
molecules– stars:
embedded IR
source (IRS1),
whereasthe N(Nmassive
2 H )/N(HC3 N) ratio at IRS1 is compa-

rable with those at the other positions. These results suggest that UV radiation affects

⼤質量クラスター形成領域NGC2264-C,
the chemistry aroundDをHC3N,
IRS1. We find that CH3OHでマッピング。野辺⼭。
there are positive correlations between thesecolumn density ratios and the excitation temperatures of N2 H+ , which implies the
2MASS点源でHC3Nが強い。N2H+/CCSが化学進化指標になるか調べた。
chemical evolution of clumps. These chemical evolutionary indicators likely reflect the
combination of evolution along the filamentary structure and evolution of each clump.
1 INTRODUCTION
clumps (e.g., Dobashi 2011; Shimoikura et al. 2013). ThereIRS1でN2H+/CCSが⾼いがHC3N/CH3OHは普通。進化ではなくUV複写。
Key words:
astrochemistry
ISM: molecules– stars: massivefore,
not only –infraredobservations
but also millimeter
The majorityこれらの⽐はN2H+の励起温度と相関。クランプの進化。
of stars are born in clusters (e.g., Lada & Lada
and submillimeter observations, which trace molecular ro-2003) and recent studies showed evidence that our Sun was
also born in such a cluster region (Adams 2010). Hence, it is1

INTRODUCTION

tational transition lines and dust continuum emission, areimportant to understandcluster-forming
regions.
Recently,
2011; Shimoikura
et al. 2013).
Thereclumps (e.g., DobashiMNRAS 491, 4310–4324 (2020)

Advance Access publication 2019 November 29

doi:10.1093/mnras/stz3344

Multiscale dynamics in star-forming regions: the interplay between
gravity and turbulence
A. Traficante ,1,2‹ G. A. Fuller,2 A. Duarte-Cabral ,3 D. Elia ,1 M. H. Heyer,4
S. Molinari ,1 N. Peretto3 and E. Schisano 1
1 IAPS - INAF, via Fosso del Cavaliere, 100, I-00133 Roma, Italy

2 Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
3 School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA, UK
4 Department of Astronomy, University of Massachusetts, Amherst, MA 01003, USA

Accepted 2019 November 27. Received 2019 November 27; in original form 2019 August 8

ABSTRACTIn this work, we investigate the interplay between gravity and turbulence at different spatial
scales and in different density regimes. We analyse a sample of 70-µm quiet clumps that are
divided into three surface density bins, and we compare the dynamics of each group with the
dynamics of their respective filaments. The densest clumps form within the densest filaments,
on average, and they have the highest value of the velocity dispersion. The kinetic energy istransferred from the filaments down to the clumps most likely through a turbulent cascade, but
we identify a critical value of the surface density, ! ! 0.1 g cm−2 , above which the dynamics
change from being mostly turbulent-driven to mostly gravity-driven. The scenario we obtainfrom our data is a continuous interplay between turbulence and gravity, where the former
creates structures at all scales and the latter takes the lead when the critical surface density
threshold is reached. In the densest filaments, this transition can occur at the parsec, or evenlarger scales, leading to a global collapse of the whole region and most likely to the formationof the massive objects.
Key words: stars: formation – stars: kinematics and dynamics – stars: massive – stars:
statistics – infrared: stars – radio lines: stars.

1 I N T RO D U C T I O N
The massive star formation involves a hierarchical, multiscale
process that starts in giant molecular clouds (GMCs), objects withsize up to tens of parsecs (Solomon et al. 1987; Roman-Duvalet al. 2010). Within GMCs, the formation of stars begins preferablyacross elongated features called filaments, which are ubiquitousSteward Observatory, University of Arizona, 933 N Cherry Ave., Tucson, AZ 85719, USA
JSPS Bonn Ofﬁce, Wissenschaftszentrum, Ahrstrasse 58, D-53175 Bonn, Germany
25
Institute for Astronomy, University of Hawaii, 640 N. A’ohoku Place, Hilo, HI 96720, USA
26
Department of AstrophysicalScience, Princeton
University,
PeytonHall, Ivy Lane, Princeton,
USA A:
High-resolution
Near-infrared
Polarimetry
andSubmillimeter
ImagingNJof08544,
FS Tau27
Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, France
Possible Streamers in Misaligned Circumbinary Disk System
28
Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyamacho, Toyonaka, Osaka 560-0043, Japan
29
1,2,3
4
5
6
2,7 240-0193, JapanSOKENDAI(The Graduate
University
Advanced
Studies),ShonanInternational
Kanagawa
Yi Yang, Eiji for
Akiyama, Thayne
Currie, Ruobing
DongVillage,, Jun Hayama-cho,
Hashimoto1,2 Miura-gun,, Saeko S. Hayashi,
30
8,9,10
11
12
3
13
1,2
Hiroshima
University,
1-3-2
Kagamiyama,
Higashihiroshima,
Hiroshima739-8511, Japan
Carol A. Grady,
MarkusJanson,Nemanja
Jovanovic,
Taichi
Uyama
,
Takao
Nakagawa,
Tomoyuki
Kudo
,
31
1,2
1,2
14
15
16
Space Telescope
Science
Institute(STScI),
3700
San MartinDr.,, Timothy
Baltimore,MD
21218,, Michael
USA Bonnefoy17,
Nobuhiko
Kusakabe,
Masayuki
Kuzuhara
,
Lyu
Abe
,
Wolfgang
BrandnerD.
Brandt32
18
20 183-900 4800 15
21
22 91109, USA
Jet Propulsion
Laboratory,
California
of Technology,
M/S
Grove
Drive
Pasadena,CA
JosephC. Carson, JeffreyInstitute
Chilcote19, Evan A. Rich
, Markus Feldt Oak, MiwaGoto, TylerD. Groff,33
1,5,23
2,5,7
24
15
25
Institute of Astronomy Olivier
and Astrophysics,
Academia
Sinica,11F of,Astronomy-Mathematics
Building,
AS/NTU
No.1,
Sec. 4, Roosevelt
Rd.,2Taipei
10617, Taiwan
Guyon,
YutakaHayanoMasahiko
Hayashi,ThomasHenning,
Klaus
W.
Hodapp
,
Miki
Ishii
,
34
2 of Technology
1 (ETH Zurich), Institute26
26
3
5CH-8093 Zurich, Switzerland
27
Swiss Federal
Institutefor
Astronomy,
Wolfgang-Pauli-Strasse
27,
Masanori
Iye,
Ryo
Kandori,
JeremyKasdin,GillianR.
Knapp,Jungmi
Kwon,
JulienLozi,
FrantzMartinache,
35
28 and Mathematics
830 5-1-5 Kashiwanoha,
31
Kavli InstitutePhysics
the Universe,
The University
Tokyo,
Kashiwa,
Chiba 277-8568,
Japan
TaroforMatsuo, Satoshi Mayama29 of, Michael
W. Mcelwain, Shoken of
Miyama, Jun-Ichi Morino2, Amaya
Moro-Martin,
36
5 Cosmosciences,
5,7 Hokkaido University,32
1,2
2 060-0810, Japan 33
DepartmentofKita-ku,
Sapporo,Hokkaido
Tetsuo 37
Nishimura , Tae-Soo Pyo, Eugene Serabyn , Hiroshi Suto , Ryuji Suzuki , Michihiro Takami,
234Institute,
TohokuUniversity,
Aoba-ku,
Sendai,L.Miyagi
980-8578,Japan
NaruhisaAstronomical
Takato5,7, Hiroshi
Terada, ChristianThalmann, EdwinTurner26,35, Makoto
Watanabe36 ,37
2,7 2019 December2,723; published 2020 February
Received
April 27;20 revised
December21;Takami
accepted
John 2019
P. Wisniewski, Toru2019
Yamada, Hideki, Tomonori Usuda, and Motohide Tamura1,2,3 3© 2020 The Author(s). Published
24 by the American Astronomical Society.

1

Astrobiology Center, NINS, 2-21-1, Osawa, Mitaka, Tokyo 181-8588, Japan; yi.yang@nao.ac.jp
National Astronomical Observatory of Japan (NAOJ), National Institutes of Natural Sciences (NINS), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan3
Department of Astronomy, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
4
Institute for the Advancement of Higher Education, Hokkaido University, Kita 17, Nishi 8, Kita-ku, Sapporo, Hokkaido, 060-0817, Japan
5
Subaru Telescope, NAOJ, NINS, 650 North A’ohoku Place, Hilo, HI 96720, USA
6
Department of Physics & Astronomy, University of Victoria, Victoria BC V8P 1A1, Canada
7
Department of Astronomical Science, SOKENDAI (The Graduate University for Advanced Studies), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
8
Exoplanets and Stellar Astrophysics Laboratory, Code 667, Goddard Space Flight Center, Greenbelt, MD 20771, USA
9
Eureka Scientiﬁc, 2452 Delmer, Suite 100, Oakland, CA 96002, USA
10
Goddard Center for Astrobiology, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
11
Department of Astronomy, Stockholm University, AlbaNova University Center, SE-106 91 Stockholm, Sweden
12
Jet Propulsion Laboratory, California Institute of Technology, M/S 171-113 4800 Oak Grove Drive Pasadena, CA 91109, USA
13
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210, Japan
14
Laboratoire Lagrange (UMR 7293), Universite de Nice-Sophia Antipolis, CNRS, Observatoire de la Coted’azur, 28 avenue Valrose, F-06108 Nice Cedex
2, France−1
15
Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany
16
The Astrophysical Journal, 889:140 (14pp),
2020
February
1
Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93106-9530, USA
17
Univ. Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble, France
18−1USA
Department of Physics and Astronomy, College of Charleston, 58 Coming St., Charleston, SC 29424,
19
Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556, USA
20
H.L. Dodge
Department of Physics & Astronomy, University of Oklahoma, 440 W Brooks St., Norman, OK 73019, USA
Original content from this
21 work may be used under the terms
Universitäts-Sternwarte München, Ludwig-Maximilians-Universität, Scheinerstr. 1, D-81679 München, Germany
22of the Creative Commons Attribution 4.0 licence.
Any further
NASA-Goddard
Space Flight Center, Greenbelt, MD, USA
23
Observatory,and
Universityof Arizona, 933 N Cherry Ave., Tucson, AZ 85719, USA
distribution of this work must maintain attribution Steward
to24the author(s)the title
JSPS Bonn Ofﬁce, Wissenschaftszentrum, Ahrstrasse 58, D-53175 Bonn, Germany
25of the work, journal citation and DOI.
Institute for Astronomy, University of Hawaii, 640 N. A’ohoku Place, Hilo, HI 96720, USA
26
Department of Astrophysical Science, Princeton University, Peyton Hall, Ivy Lane, Princeton, NJ 08544, USA
27
Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, France
28
Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyamacho, Toyonaka, Osaka 560-0043, Japan
29
SOKENDAI(The Graduate University for Advanced Studies), Shonan International Village, Hayama-cho, Miura-gun, Kanagawa 240-0193, Japan
30
Hiroshima University, 1-3-2 Kagamiyama, Higashihiroshima, Hiroshima 739-8511, Japan
31
Space Telescope Science Institute (STScI), 3700 San Martin Dr., Baltimore, MD 21218, USA
32
Jet Propulsion Laboratory, California Institute of Technology, M/S 183-900 4800 Oak Grove Drive Pasadena, CA 91109, USA
33
Institute of Astronomy and Astrophysics, Academia Sinica, 11F of Astronomy-Mathematics Building, AS/NTU No.1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan
34
Swiss Federal Institute of Technology (ETH Zurich), Institute for Astronomy, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich, Switzerland
35
Kavli Institute for Physics and Mathematics
38 of the Universe, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8568, Japan36
Department of Cosmosciences, Hokkaido University, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
37
Astronomical Institute, Tohoku University, Aoba-ku, Sendai, Miyagi 980-8578, Japan
Received 2019 April 27; revised 2019 December 21; accepted 2019 December 23; published 2020 February 3
2

Abstract
We analyzed the young (2.8 Myr-old) binary system FS Tau A using near-infrared (H-band) high-contrast
polarimetry data from Subaru/HiCIAO and submillimeter CO (J=2–1) line emission data from Atacama Large
Millimeter/submillimeter Array (ALMA). Both the near-infrared and submillimeter observations reveal several
clear structures extending to ∼240 au from the stars. Based on these observations at different wavelengths, wereport the following discoveries. One arm-like structure detected in the near-infrared band initially extends fromthe south of the binary with a subsequent turn to the northeast, corresponding to two bar-like structures detected in
ALMA observations with an local standard of rest kinematic (LSRK) velocity of 1.19–5.64 km s . Another Yang et al.
feature detected in the near-infrared band extends initially from the north of the binary, relating to an arm-likestructure detected in ALMA observations with an LSRK velocity of 8.17–16.43 km s . From their shapes andvelocities, we suggest that these structures can mostly be explained by two streamers that connect the outercircumbinary disk and the central binary components. These discoveries will be helpful for understanding theevolution of streamers and circumstellar disks in young binary systems.
Key words: binaries: close (FS Tau A) – stars: pre-main sequence – protoplanetary disks
1

2.8 Myrの連星FS Tau1. Aをすばる近⾚Hバンド偏光とALMA
CO 2-1。
Introduction
as the near-infrared observations to help understand the
すばるの腕がALMAのバーから始まっている。ALMAの腕から始まるすばるの別の構造。
dynamics in the disk. Therefore, using HiCIAO and ALMA
Over 150 planets (e.g., γ Cep Ab, Hatzes et al. 2003; Kepler
observations, we may be able to resolve the inner region of the
どちらも周連星円盤から連星へのストリーム。
16 b, Doyle et al. 2011; ROXs 42Bb, Currie et al. 2014) incircumbinary disk for the ﬁrst time.
binary or multiple systems have been conﬁrmed. To understand their formation, it is important to understand binary-disk
interactions by investigating protoplanetary disks in binary

In this paper, we present and discuss the Subaru/HiCIAO
near-infrared polarimetric data and ALMA CO (J=2–1)

Universidad de Santiago de Chile, Av. Libertador Bernardo O’Higgins 3363, Estacion Central, Santiago, Chile
European Space Astronomy Centre (ESA/ESAC), Operations Department, Villanueva de la Cañada, Madrid, Spain
10
Departamento de Astronomía,
Chile,
Casilla 36-D,
Santiago, Chile protoplanets around nearby↵ survey
TheUniversidad
widestdeH↵of accreting
11
School of Physics and Astronomy, Monash University, VIC 3800, Australia
?
12
disks
Centro de Astrobiología (CSIC-INTA), ESAC, Camino bajo deltransition
Castillo s/n, 28692
Villanueva de la Cañada, Madrid, Spain
9

1,2,3

4

5,6,7

, S. Perez8 , H. Canovas9 , S. Casassus10 ,V. Christiaens , L. Cieza1 , and N. Huelamo12

A. Zurlo 2019
, G. Cugno , M. Montesinos
Received 10 October 2019 / Accepted 9 December
11
1

Núcleo de Astronomía, Facultad de Ingeniería
y Ciencias, Universidad Diego Portales, Av. Ejercito 441, Santiago, Chile
ABSTRACTe-mail: alice.zurlo@mail.udp.cl
2
Escuela de Ingeniería Industrial, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Av. Ejercito 441, Santiago, Chile
3
Context. The mechanisms of planet
formation
are still
under
Wed’Astrophysiqueknow little deabout
howUMRplanetseven if France
more than 4000
Aix-Marseille
Université,
CNRS,
LAM –debate.
Laboratoire
Marseille,
7326, form,
13388 Marseille,
Zürich,Institutefor Particle Physics
and Astrophysics,
27, 8093theZürich,Switzerland
exoplanets have been detected 45toETH
date.
Recentinvestigations
targetthe cot ofWolfgang-Pauli-Str.
newly born planets:
protoplanetary
disk. At the first
Núcleo Milenio de Formación Planetaria (NPF), Valparaíso, Chile
stages of their life, exoplanets 6still
accrete material from the gas-rich disk in which they are embedded. Transitional disks are indeed
Instituto de Física y Astronomía, Universidad de Valparaíso, Valparaíso, Chile7
disks that show peculiarities, suchasspiralarms,Southand America
rings, whichbe connectedto the presenceof substellar
companions.
Chinesegaps,
Academyof Sciences
Center forcan
Astronomy,
National Astronomical
Observatories,
CAS, Beijing,
China
8
Universidad defor
Santiago
defeatures,
Chile, Av. Libertador
Bernardo
O’Higgins
3363,transitional
Estacion Central,
Santiago,
Chilesolar neighborhood
Aims. To investigate what is responsible
thesewe
selected
all
the
known
disks
in
the
9
European Space Astronomy Centre (ESA/ESAC), Operations Department, Villanueva de la Cañada, Madrid, Spain(<200 pc) that are visible from10 thesouthern hemisphere. We conducted a survey of 11 transitional disks with the SPHERE instrument
Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile
11
at the Very Large Telescope. ThisisthePhysics
largestsurveyMonash
that has
beenVIC
conducted
so far to look for protoplanets. The observations
School ofand H↵
Astronomy,
University,
3800, Australia
12
Centrode Astrobiología(CSIC-INTA),
ESAC,
Camino bajothat
del Castillo
s/n,in28692
la Cañada,Spain targets
were performed with the H↵ filter
of ZIMPOL
in orderto target
protoplanets
are stilltheVillanueva
accretiondestage.
AllMadrid,
the selected

are very young stars, less thanReceived
20 Myr,show
extinctionin thevisible.
10 andOctober
2019low/ Accepted
9 December
2019
Methods. We reduced the ZIMPOL pupil stabilized data by applying the method of the angular spectral differential imaging (ASDI),
which combines both techniques. The datacubes are composed of the Cnt_H↵
and the narrow band filter H↵, which are taken simultaABSTRACT
neously to permit the suppression of the speckle pattern. The principal component analysis method was employed for the reduction ofof planet
are still under
debate.
We limitsknow little
how planets luminosity.
form, even if more than 4000
the data. For each dataset, we Context.
derivedThethemechanisms
5 contrast
limitformationand converted
it in
upper
on about
the accretion
exoplanets have been detected to date. Recent investigations target the cot of newly born planets: the protoplanetary disk. At the first
Results. We do not detect anystages
newofaccreting
substellar
the targeted
disks
downTransitional
to an averagecontrast
their life, exoplanets
stillcompanions
accrete material aroundfrom the gas-richdisk in transition
which they areembedded.
disks areindeed of00
12 magnitudes at 0. 2 from thedisks
centralstar.peculiarities,
We have recoveredof rings,
the accreting
Mconnectedstar companion
aroundthe star
HD 142527.
that showsuch as gaps, thespiralsignal
arms, and
which can beto the presenceof substellar
companions.
Aims.
investigate
what isfor thesefeatures,we selected
all theHD
known
transitional
the solarsystem,neighborhood
We have detected and resolved,
forTothefirst time
inresponsible
visible light,
thequadruple
system98800.
For disks
everyin other
we can(<200 pc) that are visible from the southern hemisphere. We conducted a survey of 11 transitional disks with the SPHERE instrument
exclude the presence of massive
activelyaccretingcompanions,assumingthat
theaccretionisnotepisodic
and
that
the
extinction
at the Very Large Telescope. This is the largest H↵ survey that has been conducted so far to look for protoplanets. The observations is
600
negligible. The mean accretionwere
luminosity
limit
L ZIMPOL
at a separationof 0.protoplanets
2 from theperformed with
the isH↵10filter ofin order to target
thathost.
are still in the accretion stage. All the selected targets
are very young stars, less than 20 Myr, and show low extinction in the visible.

Methods.
We reduced–the
ZIMPOL pupil stabilized
by applying themethod of the–angular
spectralaccretion
differential imaging
Key words. planets and satellites:
formation
protoplanetarydisks –dataplanet–diskinteractions
accretion,
disks –(ASDI),

which combines both techniques. The datacubes are composed of the Cnt_H↵ and the narrow band filter H↵, which are taken simultatechniques: high angular resolution
neously to permit the suppression of the speckle pattern. The principal component analysis method was employed for the reduction of

TDのサブ構造の起源。VLTSPHERE,
11theTDs,
Hα。
the data. For
each dataset, we derived
5 contrast
limit and converted it in upper limits on the accretion luminosity.
Results. We do not detect any new accreting substellar companions around the targeted transition disks down to an average contrast of
１２等のコントラストで新しいsubstellar伴星はなし。
12 magnitudes at 0. 2 from the central star. We have recovered the signal of the accreting M star companion around the star HD 142527.
We have detected and resolved, for the first time inhydrodynamical
visible light, the quadruple
system HD 98800.
For every
system, weof
cansubstellar
simulations
predicted
theotherpresence
1. Introduction
exclude the presence of massive actively accreting companions, assuming that the accretion is not episodic and that the extinction isHD142527のM型伴星は検出。HD98800の四重連星を可視光で初分解。
aroundsome
TDs (e.g., Dong et al. 2016a).
negligible. The mean accretion luminosity limit is 10companions
L at a separationof 0. 2 fromthe observed
host.
-6
Detectingforming
protoplanetsisthecornerstonetounderstandAccreting
giant planets
are– accretion,
thoughtaccretion
to develop
降着光度の制限は10 Lsun。
Key words. planets and satellites: formation – protoplanetarydisks – planet–diskinteractions
disks – a circumplan00

6

ing planet formation (Fortney ettechniques:al. 2008;
Spiegel& Burrows
high angularresolution
2012; Mordasini et al. 2017). Approximately 30% of Herbig
Ae/Be disks should host giant planets of ⇠0.1 to 10 MJup (KamaIntroduction
et al. 2015). Some Herbig 1.
stars
host transitional disks (TDs),

00

etary disk (CPD) as they interact with the circumstellar material(e.g., Miki 1982; Gressel et al. 2013; Perez et al. 2015). While afraction of themass flows through the CPD at midplane latitudes,hydrodynamical simulations predicted the presence of substellar
a substantial amount of gas falls onto the surface of the CPD via