Star Formation Newsletter#364 15-28
Yusuke Aso (KASI)

determines whether the binary transfers angular momentum to the

In orderto understan
where
ri ,&vNixon
thepositionof the gas particle
thatis
1 We note that since we haveOnce formed,
a coplanar
circumbinary disccan inextendtodisc or viceversa (Heath; Tiedeet al. 2020).and
Howevelocityver,i are2020
performed
convergence
tests
ourdown
previous
Downloaded from

CSD

(Pringle 1981; Lodato 2008).

Downloaded from https://academic.oup.com/mnras/article/522/1/1569/7116479 by KASI user on 19 June 2023

maintainan almostconstant
mass
per cellentering
during thetheNavier–simulations our conclusions.
We herealso include
the effectof gasviscosityon the binary iswhen
a finite-volumeschemeis
employed.
In
this
work,
we
exploitfluid
equationsTheas describedin
Hopkins(2016),
assuminga
Stokesimportance of live binary evolution in numerical simulations
of
N
N
!
!
the
particle-splitting
algorithm
in
GIZMO
,
splittinggas
particlesthatGM
GM2 mi ( r i − r 2 )shear viscosity in the binaries
disc ν = αcusing a viscosity
1 mi ( r i − r 1 )s H, parametrized
embeddedin circumbinary
discs
TEGS=
r1 ×
+
r
×
, (1
3
R
U
LT
S
2
3
3
enter aαsphereof radius &rrefSunyaev= 4a centred
thenocentreof mass of theparameter= 0.1 (Shakura1973),onandbulk viscosity.
|
r
−
r
|
|
r
−
r
|
i
1
i
2
i=1
i=1
2‹
1,2,3
1,2
4
Alessia,1,whenAlessandro
Lupi,necessary,
AlbertoandZoltanHaimanthe
system.
TheFranchinirefinement
schemeiswherethe sameas the Sesana
one WeInbinary–discorder to increase
theresolution
andhere
describe
resultsofouranalysiscomparing the torques
1 Dipartimento di Fisica ‘G. Occhialini’, Universitá degli Studi di Milano-Bicocca, Piazza della Scienza 3, I-20126 Milan, Italy
where
m
is
the
particle
mass,
and
r
,
r
i
1
2
adoptedinFranchini
et
al.
(
2022
)
with
a
maximum
refinementofa
2 INFN, down
without globally slowing
our simulations,
we employanItaly
onSezione di Milano-Bicocca,
Piazza della Scienza
3, I-20126 Milan,in the live and fixed orbit binary simulations. are the sink positions wit
3 DiSAT, Università degli Studi dell’Insubria, via Valleggio 11,
CBD
CBD
CSD
I-22100 Como, Italy
respect to the binary centre of mass. Since this quantity is subjec
factorof 32.particle-splitting
the-flyadaptive
approach,whichNew
is York,similarinUSA
spirit4 Department of Astronomy,
Columbia University,
NY 10027,
to fluctuations on very short time-scales, we calculate the averag
Every timea gas
particle ofapproachesof thesinks,
entering its
to the adaptivemeshrefinement
grid-basedone
codes.
Such
techniquevalueaccretionof ,thegravitationalforboth thelive and fixed binar
3.1 Gasand gravitational
forcessink SPH,
radiusrsink , generalization
we
flag2023
it April
as eligible
torefinement/de-refinementbe
In2023
theFebruary
live 22binary
3D, 106 represents
2of the2023(PHANTOM),
2a-10a,H/R=0.1,
Σ ∝torque
𝑅 !".$,M
a natural
Accepted
5. Received
Aprilaccreted.
3; in original form
disk=0.1Mbinary
simulations over the 700 orbits that we are considering. We find tha
case,inconservationof mass,
andlinearandangularadaptive
momentumareschemeAREPO(Springel
2010
) and
GIZMO
(Hopkins2015) to particle
GIZMO meshlessfinitemass
mode,
α=0.1,
splitting,
The ingravitational
torque that the distribution of gas particles exerts
thefixed orbit case, the time-averaged gravitational torque valu
ensuredduring each
event,
in during
the sameway
it is done inmaintainan almostconstant
per
cell
the
simulations
A B S Taccretion
R A CmassTon theis
⾒ The1000
700
is binaryhigherbyadvocated∼5 perascentcomparedto the live binary case.
shrinkingBonnell
of a binary &orbitPricedriven 1995
by the interactiona gaseous circumbinary
disc, initiallya potential
way
PHANTOM code
(Bate,). wewithwhenthea finite-volumeschemeis
employed.
In
this
work,
exploitto catalyse the binary merger, has recently been debated in the case of geometrically thick
H/R !
0.1) discs.is
However, N the binary angular momentum
N (i.e. with
When
a gas
particle
In this work,algorithm
we neglect
the disc
self-gravity(see Franchini,!
the particle-splittingin GIZMO, splitting
gas toparticles
thatr i − r 1accreted,) !
GM2 mi ( r i − r 2 )a clear consensus
is still missing
mainly owing
numerical limitations,such as fixed orbit binariesGMor lackofi (resolution
inside
1m
T
=
r
×
+
r
×
, (1)
changesby700
5%
G the importance
1
2
& of
Dotti
2021
forcarved
self-gravity
treatment)
and useversionthercavity
by the binary
in its circumbinary
disc.theIn thiswork, we assessof evolving the binary
orbit
3
3
enterSesanaa sphereradiusref = 4a centred on the centre of mass of the
|
r
−
r
|
|
r
−
r
|
i
1
i
2
by means of
performed
with(2022
the code
1 mass mode. In order to model the i=1of the code
inhydrodynamic
detailschemein simulations
Franchini
et al.as). GIZMO
The in meshlessi=finite
dL describedmi Mk
binary–discsystem.
The
refinement
is thebinaries
same
the
one
interaction
between equalmass circularand their
locally
isothermal circumbinary discs, we enforce hyper-Lagrangian
d
L
=
r
×
m
v
−
(2
[( r i − r k ) × (v i − v k )] ,
acc
i
i
i
where
moi visthe particle
mass,
and
resolution
inside)thecavity.
find that fixing
the binary orbit
leads to an
erestimateof the gravitational
torqueadopted in Franchinial. (2022
witha We
maximum
refinementof ultimately
a
dL
9% et
(mi +
Mrk1), r2 are the sink positions withthat the gas exerts on the binary and an underestimate of the torque due to the accretion of material on to the binary components.
respect period
to thebinarysuppressed
centreinofthemass.
Since this quantity is subject
factor of 32.
()
Furthermore, we find that the modulationof the accretion
rate on the7%binary orbitalis, strongly
fixed
where
r
v
are
the
positionandvelocityof the gas particle that i
1 We note that sinceiiwesimulation,
have
performed
convergenceinbinary
our simulations.
previous
to fluctuations
on veryfor short
time-scales,
we calculate
the average
orbit
while it isclearlyin tests
the liveThis
has potential implications
the predictionofEvery time a gas particle
approaches
oneof present
the sinks,
entering
its
being
accreted
and
r
,
v
are
the
positionandvelocity
the sinkk
al. observable), we
do not repeat
those
tests
thecandidates.
fixed binary value of the gravitational torque for both the live and fixed oftheperiodicities
massiveblackhole inbinary1572
A. Francsink
hini etworkal. (Franchiniradiusrsink , we etflag
it2022
as eligible
to beinaccreted.
Inthebinary
live
binaryparticle that is accreting. Note that the second term on the r.h.s
orbit case as we havea high enoughfor the torquevaluesKeyreachedwords: accretion,accretion resolution
discs – hydrodynamics– binaries:
general.simulations
over the 700 orbits that we are considering. We find thatFixe
case,toconservation
of
mass,
and
linearandangularmomentumareconverge.
contributes to the spin of each binary component. In the fixed binar
orbit simulations,in the fixed orbit case, the time-averaged gravitational torquevalue resensured during each accretion event, in the same way it is done in
the strong positive c
is higher by ∼5 per cent compared to the live binary case. from the external par
the PHANTOM code (Bate, Bonnell & Price 1995).
discs can be positive and, in a specific region of the parameter space,feeds this disc exerts
1 I N T RO D U
CTION522,we1569–1574(2023)a gas particle
accreted,negative gravitational
torque of the iscircumbinary
disc. the binary angular momentum
InMNRAS
this work,neglect thedisc self-gravity (see Franchini,overcome the WhenIn general, the magn
Circumbinary discs are expected to surround both stellar binaries
Recent 2D hydrodynamic simulations have suggested that thechanges
by
100Pb is essentially c
Sesana & Dotti 2021 (e.g.
forChiang
self-gravity
treatment)use) andthemassive
versionexchange of angular momentum between the disc and the binary& Murray-Clay
2004; Kennedyand
et al. 2019average the torque ov
blackinholedetailbinaries (MBHBs).
Although weet
stillal.
lack (
unambiguous
predictionsof the code describedin Franchini2022). Thecan also lead to binary expansion, contradicting previous
has reached a quasi-sMm˜˜ et al. 2020i). Inkparticular,
observational evidence of the latter, any cloud of gas approaching the(Munoz,Miranda & Lai 2019; Munoz
d
L
=
r
×
m
v
−
(
r
−
r
)
×
(
v
−
v
)
,
(2)
[
]
acc
i
i
i
i
k
i
k
binary on a non-zero angular momentum orbit is expected to form
for locally isothermal discs, several 2D with fixed binary orbits and
(
m
+
M
)
i
k
3.2 Gravitational toa circumbinary disc due to the conservation of angular momentum
3D with live binaries works have argued that the disc aspect ratio
we produced maps

being accreted and r , v are the position and velocity ofsimulations.
the sink
Fig. 3 shwork (Franchini et al. 2022), we do not repeat those tests in the fixed binary
by the binary in the cdiscrete alocations(Lindblad resonances),to theexchange
regulated by
the disc
but also
by thethat
disc the second term on the r.h.s.
particlethatis temperatureaccreting.
Noteorbit case as we have reachedhigh enoughresolutionleading
for thetorquevaluesto be simply
represents the fixed (of angular momentum between the disc and the binary (Lyndenviscosity. The picture becomes even more complicated if we consider
100 orbits,
i.e. in the ito converge.
contributes toFigure
the1.spinof eachcomponent.
the fixed
binaryCumulative
accretionbinary
torque (orbital
angular momentumIn+ spin)Figure 3. Total gravitational torque distribution inside the cavitya averaged
overthethebinary
last 100separation
orbits (i.e. (Artymowicz
1600−1700 Pb ).&Left-handbinary.
few times
Lubow panel:1994).Live orbit
using
very high resolution 3D hydrodynamical simulations of live
Middle panel: Fixed binary. Right-hand panel: Difference betweenThethe liveand fixed binary
maps.
circumbinary
discorbit
orbitsresonate with the binary orbit atbinaries, Franchini, Lupi & Sesana (2022)kfoundk this process not

The importance of live binary evolution in numerical simulations ofbinaries embedded in circumbinary discs

CSD

Fixed versus live binary orbits

1573

ABSTRACT
correspond to t = 1400 Pb and t = 1700 Pb , respectively. The cyan
The shrinking
of a binary
driventheinteraction
witha gaseous
circumbinary disc, initially advocated as a potential way
dashedcircle isorbit
locatedat r =by2.9a, i.e.
the distancethat
corresponds
to catalyse themerger,has recently
debatedin thecaseof geometrically thick (i.e. with H/R ! 0.1) discs. However,to binary
the 0.2 !
whilebeen
the whitedashedcircleis locatedb,0 modulation,a clear consensus
is still missing
mainly owing
at the distancethat corresponds
to the 0to.45numerical!b,0 orbitallimitations,modulation.such as fixed orbit binaries or lack of resolution inside(

Lindblad)

1.59a

the cavity carved by the binary in its circumbinary disc. In this work, we assess the importance of evolving the binary orbit
by means of hydrodynamicFixedsimulations
withorbits
the code GIZMO
versusperformed
live binary
1573in meshless finite mass mode. In order to model the
4 DISCUSSION
interaction between
equal mass circular binaries and their locally isothermal circumbinary discs, we enforce hyper-Lagrangian
correspondto orbits
t =We
1400
Pb thatand tfixing= 1700, respectively.
cyan leads to an overestimate of the gravitational torqueFixingbinaryinfindcircumbinary
disc
aThe
widelyresolution insidethecavity.
thePbsimulations
binaryorbitisultimately
dashedcircleis locatedat an
r =underestimate
2.9a, running
i.e. the distancethat
corresponds
adoptedstrategy,
in particular
when
2D
(but
sometimes
also
that
the
gas
e
x
erts
on
the
binaryandofthetorquedue
to the accretion of material on to the binary components.
Figure 4. Circumstellar discs surface density profiles in the live (blue andFigure5..2 !
FFT
theusing
accretion
rateonto(eitherthe binary
the
live
line)
to
thefind0simulations
modulation,
whilethethewhite
dashedcirclelocated
in
3D)
grid
codes
withforstaticoris(blue
movingb,0 ofFurthermore,
we
that
the
modulationofaccretion
rate
on
the
binaryorbital period is strongly suppressed in the fixedcyan lines) and fixed (orange and red lines) simulations as a function of radiusandthefixed(orangeline)
binaryorbittosimulations.
binaryatdistancethatcorresponds
the0.45easier!bThemodulation.
mesh
grids).
Since
particle
codes
are
much
toinitial
run bothliveorbital
and,0 orbitalin units of the initial binary separation.
orbit simulation,
while
it is clearlyin the live binary simulations. This has potential implications for the prediction of
frequency
is denotedby !b,0present.
fixedbinaryorbit simulations,
we test whether this approximation
the observable
periodicities
inmassiveblack
holebinarycandidates.
can lead to significant differences interms
of gasdynamics and

lump
0.2
4 D I S CinUterms
S S I OofNtorques exerted by the gas on to the binary.
Key words: therefore
accretion,accretion
discs – hydrodynamics – binaries: general.
3.5
Accretion
rate modulation
We find several differences1574
between theruns:both binary and disc eccentricity growth (Teyssandier & Ogilvie
A.twoFranchiniiseta al.
Fixing binary orbits in circumbinary
disc
simulations
widely0.452016). Previous studies have found that, if there is material locatedSince by 1000 P b the disc in the live binary simulation has reached a

(

)

lump

Downloaded from https://academic.oup.com/mnras/article/522/1/1569/7116479 by KASI user on 19 June 2023

Accepted 2023 April 5. Received 2023 April 3; in original form 2023 February 22

CBD

10

adoptedstrategy,
in particularwhentorunning
2D (but sometimes
also(i) Fixing
the binary
orbit leads
an overestimateof the gravquasi-steadystate, wecan analyse
the variabilityof static
the accretion
rate
AC K N OW L E D G E M E N T S
in3D) simulations
using(eitherwithmovingitational
torque exerted
bygridthe codes
disc onto thebinarybyorabout5
on to the binary Ṁ . This study is important in order to understandmeshgrids).
Since
are much
to runbothdiscs
live and
Weofthank
the anonymous
per
cent.
Since
theparticle
balancecodes
betweenthe easierpositive
torquecomingcan be positive and, in a specific region
the parameter
space, referee for providing useful comments thatwhich
we can expect to observe from these systems.
1 I N T RO Dfrom
U C TtheIperiodicities
Ocircumstellar
N orbit simulations,
fixedbinarywhether
this approximation
vcircumbinary
ed the clarity ofthe paper. We thank Daniel Price for providing
disc andwe
thetestnegativ
e torquecomingfrom the negative gravitational torque improov
ercomeofthedisc.
the outer circular Lindblad resonance located at the 3:2 binary-toWe calculated the Fast Fourier Transform (FFT) of the accretion
can
lead
to
significant
differences
instellarof gasovdynamics
andPHANTOM
code
forthenumerical simulations and acknowledge thethecircumbinary
disctoissurroundvery delicate,
atermssystematic
erestimate
of 2D hydrodynamic simulations the
Circumbinary
discs
are
expectedbothbinaries
Recenthavesuggestedthatdisc frequency commensurability, i.e. at 1.59a, is strong enough torate on the binary in the two simulations. The result is shown in Fig. 5
therefore
in
terms
of
torques
e
x
erted
by
the
gas
on
to
the
binary.
useof
SPLASH(Price2007) for the rendering of the figures. We
one
of
the
two
contributions
can
bias
the
outcomeinterms
ofbinary(e.g. Chiang & where
Murray-Clay
Kennedy
et al.
2019) andtrigger eccentricity growth in equal mass binaries.
the blue2004
and ;orange
lines
represent
the massive
live and fixedexchangebinaries, of angular momentum between the disc and the binary
We(MBHBs).
find severalAlthoughdifferences
betweenthetwo runs:
thankprevious
Phil Hopkins
for providing the GIZMO code for numericalevolution.
black
hole
binaries
we
still
lack
unambiguous
can
also
lead
to
binaryexpansion,
contradicting
predictions
We calculate the disc eccentricity profile, averaging it over the lastrespectively. The most striking difference between the fixed and live
and AS acknowledge financial support provided(ii) Simulations
thatuse
fixedofbinary
orbits (in both
2D (Muand noz,3D)˜
˜ etsimulations.
ational ebinary
videnceof thethelatter,cloud
gastoapproaching
the orbital
Miranda & Lai 2019; Munoz
al. 2020). InAF
particular,
100 binary orbits, finding that the cavity is slightly more observ
eccentric
simulations
is anythatorbit
the modulation
binary(i) Fixing
binary
leads
anon
ovthe
erestimateof theperiod
gravFigure 6. Accretion rate on to the binary for the live and fixedbinaryundertheEuropean
Union’s
have shownthat momentum
the accretion
contribution
to to
theform
torque exfor
erted
on isothermal discs, several 2D withbinaryonanon-zeroangularorbit
isexpected
locally
fixedbinaryorbitsand H2020 ERC Consolidator Grant ‘Binary
in the fixedrepresented
binary orbit
due respectively,
to the fact asthatis presenttorqueonly inethelatter,byi.e.thethediscpeakonat !/1 is missingin theitational
xertedto!thebinaryby about
5b,0 =simulations,by simulation,
the blue and probably
orange lines,a
MassiveBlack
Hole
Astrophysics’ (B Massive, grant agreement
thebinaryisalways
negligible
comparedtothegravitational
torque.
a circumbinary
disc
dueSince
tothetheconservationofwith live binaries works have argued that the disc aspect ratio
the trajectories
the gasparticles
remainessentially unvaried
if thefixed
orbit
simulation.
The lack
ofangular
this feature
has alsotorquebeen 3D
observedpercent.
balancebetweenthemomentum
positivecomingfunctionof time inofunitsof thebinary orbital
period.
no. 818691).
AL acknowledges
funding from MIUR under grantHowever,2008
we hereshow that fixing the binary orbit does indeed
lead whether the binary transfers angular(Pringle
1981;
Lodato).
determines
momentumtothe˜ et coming
binary does not change its orbit with time.
in Farrisal. (2014) and
in Mu
noz
al. (2020from
) for
from
the etcircumstellar
discmoreand recently
the negativ
e torquePRIN
2017-MB8AEZ.
ZH acknowledges support from NSF grants
to underestimating
the accretion
torqueby 9 down
per cent
over discthe or700
Onceformed,acoplanarcircumbinary
disc
canextend
to
vice
versa
(Heath
&
Nixon
2020
;
Tiede
et
al.
2020
).
Ho
we
ver,
We find an exponential growth of the disc eccentricity in our live
equal
mass circularbinariesto theones we aretreating here.
thecircumbinary
disc
is verysimilardelicate,a systematic
overestimateofAST-2006176
andof
1715661
orbitswe ran.
Furthermore,
we can see
from the1994
upper
panelusing
in Fig.
times thebinary(Artymowicz
Lubow).termsvery high resolution 3D hydrodynamical
simulations
live and NASA grant 80NSSC22K082. Thisbinary simulation after the first few tens of binary orbits,a few
despiteNote
the twoadjacent
peaks
at&the!/!outcomecorrespondto theone
ofthatthe separation
two
contributions
can biasof binaryb,0 = 1 in
was process
supported
1 that discthe difference
betweenwith
the twotorques
keeps atincreasingover Franchini, Lupi & Sesana (2022research−5The
circumbinary
orbitsresonatethebinaryorbit
binaries,
)
found
this
notin part by the National Science Foundation
the very low binary eccentricity (i.e. eb = 3 × 10 ). The material
natural variation of the binary orbital frequency in the live binary
evolution.
underbut
grant
no.
NSF
PHY-1748958.
time (Lindblad
and mightresonances),be even moresignificant
after
a few thousandsof
discretelocationsleadingtotheexchangetobesimplyregulated
by
the
disc
temperature
also
by
the
disc
leaking into the cavity indeed reaches 1.59a within the first ∼10
simulation.
(ii) Simulations that use fixed binary orbits (in both 2D and 3D)
binary orbits.
of angular momentum
betweendisc andthebinary(Lyndenorbits and is therefore able to excite one of the Lindblad resonancesFig.
6 shows
accretion
rate
on to
the binary
directly
have
shown
thatthethetheaccretion
contribution
tothe calculated
torque exviscosity.
ertedon The picture becomes even more complicated if we consider(iii) We find the circumstellar disc density to be slightly higher

Figure6. anAccretion
rate on to
the binary
for the live
and
fixed
binaryat eitherouter circular
Lindbladresonance
(at R
a) or
at a
L >
simulations,represented
by Lindblad
the blue andorange lines,anon-co-orbital
eccentric
resonance(at Rrespectively,
disc
L "= a), the asfunctionof eccentric.
time in unitsof the binary&orbital
period. ć (2008) showed that
becomes
MacFadyen
Milosavljevi

lump

Downloade

Downloaded from https://academic.oup.com/mnras/article/522/1/1569/7116479 by KASI user on 19 June 2023
Downloaded from https://academic.oup
Downloaded from https://academic.oup.com/mnras/article/522

Figure 3. Total gravitational torque distribution inside the cavity averaged over the last 100 orbits
1600−1700 Pb ). Left-handLive orbit binary. 1,2,3
Alessia Franchini ,1,2 ‹(i.e.
Alessandro
Lupi ,1,2panel:
AlbertoSesana and Zoltan Haiman4
Middle panel: Fixed binary. Right-hand panel: Difference between1 the live and fixed binary orbit maps.
Dipartimento di Fisica ‘G. Occhialini’, Universitá degli Studi di Milano-Bicocca, Piazza della Scienza 3, I-20126 Milan, Italy
2 INFN, Sezione di Milano-Bicocca, Piazza della Scienza 3, I-20126 Milan, Italy
3 DiSAT, Università degli Studi dell’Insubria, via Valleggio 11, I-22100 Como, Italy
4 Department of Astronomy, Columbia University, New York, NY 10027, USA

TheALMASurvey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). VIII.
Dynamics of Embedded Dense Cores
Shanghuo Li1 , Patricio Sanhueza2,3 , Qizhou Zhang4 , Garay Guido5 , Giovanni Sabatini6 , Kaho Morii2,7 , Xing Lu8 ,Daniel Tafoya9 , Fumitaka Nakamura2,3 , Natsuko Izumi10 , Ken’ichi Tatematsu2 , and Fei Li111

Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany; shanghuo.li@gmail.com, li@mpia.de
National Astronomical Observatory of Japan, National Institutes of Natural Sciences, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan3
Department of Astronomical Science, SOKENDAI (The Graduate University for Advanced Studies), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
4
Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
5
Departamento de Astronomía, Universidad de Chile, Las Condes, Santiago, Chile6
INAF—Istituto di Radioastronomia—Italian node of the ALMA Regional Centre (It-ARC), Via Gobetti 101, I-40129 Bologna, Italy
7
Department of Astronomy, Graduate School of Science, The University of Tokyo, 2-21-1, Osawa, Mitaka, Tokyo 181-0015, Japan
8
Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030, People’s Republic of China
9
Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala, Sweden
10+
1811F of AS/NTU Astronomy-Mathematics Building, No.1, Section 4, Roosevelt Road, Taipei 10617,
Academia
Sinica +Institute of Astronomy and Astrophysics,
2
2 Taiwan
3
11
School of Astronomy and Space Science, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, People’s Republic of China
Received 2023 January 1; revised 2023 March 16; accepted 2023 March
3 17; published
2 2023 June 221 pc
0.1 pc<5.5 kpc, warm core
12
IRDC 0.023 pc (4800 au)
ALMA 12m+7m, N D , DCO (0.17 km/s), C O, H CO, CH OH (1.3 km/s)
dendrogram
12294(CH OH, H CO)(CO, SiO, H2CO)
protostellar (97 )presertllar (197 ) Abstract NH3 (5") ~15 K

The Astrophysical Journal, 949:109 (22pp), 2023 June 1

Li et al.

We present dynamical properties of 294 cores embedded in twelve IRDCs observed as part of the ASHES Survey.
Protostellar cores have higher gas masses, surface densities, column densities, and volume densities than prestellar+ phase. We ﬁnd that ∼80% of cores with virial
cores, indicating core mass growth from the prestellar +to the protostellar
2parameter (α) measurements are gravitationally bound(α < 2). We also ﬁnd an anticorrelation between the mass and
18 on average lower virial parameters. Protostellar cores are
the virial parameter of cores, with massive cores having
more gravitationally bound than prestellar cores, with an average virial parameter of 1.2 and 1.5, respectively. The
observed nonthermal velocity dispersion (from N2D+ or DCO+) is consistent with simulations in which turbulence is
The AstrophysicalJournal,949:1092023 June1virdispersiongas(22pp),
continuously injected, whereas the core-to-corevelocityis neither
in agreementwith driven nor decaying
turbulence simulations. We ﬁnd a not signiﬁcant increment in the line velocity dispersion from prestellar to
protostellar cores, suggesting that the dense gas within the core traced by these deuterated molecules is not yet
severely affected by turbulence injected from outﬂow activity at the early evolutionary stages traced in ASHES. The
most massive cores are strongly self-gravitating and have greater surface density, Mach number, and velocity
dispersion than cores with lower masses. Dense cores do not have signiﬁcant velocity shifts relative to their lowdensity envelopes, suggesting that dense cores are comoving with their envelopes. We conclude that the observed coreproperties are more in line with the predictions of clump-fed scenarios rather than with those of core-fed scenarios.

N D , DCO
) C O
α=M /M(73<1, 2844%(91%)
1-2, 28>2,
Li et al.

Uniﬁed Astronomy Thesaurus concepts: Infrared dark clouds (787); Star forming regions (1565); Star formation(1569); Massive stars (732); Protostars (1302); Interstellar line emission (844); Interstellar medium (847);
Protoclusters (1297)
Supporting material: machine-readable tables

mass growth

1. Introduction

(2)

R
(pc)
(4)

Npeak(H2)(×1023 cm−2)(5)Σ(g cm−2)
(6)

T NH3
(K)
(7)

1
2
3
4

6.90
1.68
3.10
2.05

0.024
0.009
0.013
0.014

1.62
1.53
1.57
1.06

0.78
1.41
1.27
0.70

13.4
12.5
12.1
14.2

Core

(1)
G10.99G10.99G10.99G10.99−1

between 0.16 and 0.28 central
km s , protostellar
with a meanvalue
densities
from prestellar cores (see also Table 4). A
objectand ofis on thevergethanof those
gravitational
responsible
High-mass stars (M  8 Me) are mainly 0.23
trend
found in the individual clumps, except for
km s−1. for thecollapse (Ward-Thompson et al. 1994;similar
Redaelli
et al.is 2021).
chemicalenergyinjectionσ
M enrichment
αa and kineticaSF
G331.37,
G340.17,
G340.22. The latter two clumps are
We foundintothat thethe values ofthe virialcoresmassesrepresent
range fromPrestellar
the startingpoint
in theandstar(km s )(M )(pc Myr )(pc Myr )
still
at
very
early
evolutionary
phases as evidenced by theinterstellar
medium(ISM)ofgalaxies(Kennicutt
1998;
McKee
,
and
the
mean
value
is
1.89
M
for
all
the
0.22
to
8.61
M
e
e
(8)
(9)
(10)
(11)
(12)
(13)
formation process. Different
high-mass star formation theories
nondetection of molecular outﬂows. The G331.37 hosts 1/M
rangescores
analyzed.
parameterα=M&& Yorke2007).
A129
great
progress
hasThe virial
vir
gas
0.34Ostriker
2.47 2007;
0.36 Zinnecker
10.54
5.09
3
predict very different initial conditionsrelatively
for the massive
prestellar(7.96
cores.
0.34
0.78
18.99
1
M ) prestellar core, while the rest offrom
0.15 to 8.91,
with a mean value of 1.39. Seventy-three out
been
made
in 0.46
investigating
the 13.45
basic propertiesof high-mass
starInthecore-fedorcore-accretion
models,amolecular
cloude cores have comparable mass
0.47
2.14
0.69
17.19
18.49
1
the
prestellar
andprotostellarof 129 cores have virial parameters below 1, 28 cores have

Table 2
Summary of Dense Cores’ Properties

Mgas
(Me)
(3)

Clump

estimator. The blue horizontal bars
from the top to bottom in each violin plot represent the maximum, mean, and minimum values, respectively.
prestellar
protostellar
called a prestellar core. A prestellar core has not yet formed any

Figure 4. Violin plots of the % distributions for each line. The shape of each distribution shows the probability density of the data smoothed by a kernel density

Figure 1. Panels (a)–(d) show the histograms of the peak column density (Npeak(H2)), gas mass (Mgas), surface density (4H2 ), and volume density (n H2 ) for theprestellar and protostellar cores. The black and red dashed vertical lines indicate the median values of prestellar and protostellar cores, respectively.

tot
−1

0.24

vir

G

e

0.66

0.32

9.52

−2

K

4.48

−2

3

TheALMASurvey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). VIII.
Dynamics
Embedded
Cores
Figure 5. Panel (a)upper
panel showsof
the numberof sources perDense
mass bin, andthe bottom panel shows a box plot of the values of the virial parameter per bin. In thebox plot, the mean value of the virial parameter is shown with a horizontal line. Panels (b) and (c)α vs. mass for all the cores where molecular emission from either

8 panel (c) shows the cores color
or DCO 2,3was ,detected.
(b) 4shows
the cores
color5codedby their evolutionaryclassiﬁcation(Li et ,al.Xing2022),
N2 D
Shanghuo Li1 , Patricio
Sanhueza
QizhouPanel
Zhang, Garay
Guido, Giovanni
Sabatini6stage, KahoMorii2,7
Luand
,
coded
ﬁgures shows the linear regression
in the plot, gives a slope of −0.61 ± 0.06; and the
9 by their parental molecular cloud.
2,3 The solid line in both10
2 to all the point 11
Daniel Tafoya,
Fumitaka
Nakamura,
Natsuko
Izumi,
Ken’ichiTatematsu
,
and
Fei
Li
gray shadowed area shows the 1σ conﬁdence interval for the ﬁt. The Spearman’s rank test returns a coefﬁcient of r = −0.68.
++

1

Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany; shanghuo.li@gmail.com, li@mpia.de s
National Astronomical Observatory of Japan, National Institutes of Natural Sciences, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan3
Department of Astronomical Science, SOKENDAI (The Graduate University for Advanced Studies), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
4
Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
5
Departamento de Astronomía, Universidad de Chile, Las Condes, Santiago, Chile6
INAF—Istituto di Radioastronomia—Italian node of the ALMA Regional Centre (It-ARC), Via Gobetti 101, I-40129 Bologna, Italy
7
Department of Astronomy, Graduate School of Science, The University of Tokyo, 2-21-1, Osawa, Mitaka, Tokyo 181-0015, Japan
8
Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030, People’s Republic of China
9
Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala, Sweden
10
Academia Sinica Institute of Astronomy and Astrophysics, 11F of AS/NTU Astronomy-Mathematics Building, No.1, Section 4, Roosevelt Road, Taipei 10617,
Taiwan11
vir
School of Astronomy and Space Science, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, People’s Republic of China
Received 2023 January 1; revised 2023 March 16; accepted 2023 March 17; published 2023 June 22

pressure-confined
protostellar
M
Mgas

α

Mgas 2/3

Abstract
We present dynamical properties of 294 cores embedded in twelve IRDCs observed as part of the ASHES Survey.
Protostellar cores have higher gas masses, surface densities, column densities, and volume densities than prestellar
cores, indicating core mass growth from the prestellar to the protostellar phase. We ﬁnd that ∼80% of cores with virial
parameter (α) measurements are gravitationally bound (α < 2). We also ﬁnd an anticorrelation between the mass andthe virial parameter of cores, with massive cores having on average lower virial parameters. Protostellar cores are
more gravitationally bound than prestellar cores, with an average virial parameter of 1.2 and 1.5, respectively. The+ virial parameter
Figure 5. Panel (a)upper panel shows the number of sources per massbin, and thebottom
panel
shows
a box
plot ofthevaluesbin. virial
In thewithDtheordensity.
DCO+Right) is perconsistent
simulations
in whichturbulence
observed
nonthermalvelocity
dispersion(fromNof2surface
Figure6.
Left panel:virialparametervs.
panel:
parametervs. peak column
density.
The blueissolid line in both ﬁgures shows the linear
box plot, the mean value of the virial parameter is shown with a horizontal line. Panels regression(b) and (c)α
vs.
mass
for
all
the
cores
where
molecularemission area
fromshowseither the 1σ conﬁdence interval for the ﬁt. The best ﬁt gives a slope −1.22 ± 0.15 and
to
all
the
point
in
the
plot,
and
the
gray
shadowed
continuously
injected,
whereasthecore-to-corevelocity
dispersion
isneitherinagreement
withdrivennor
decaying++classiﬁcation(Li α–
et N
al.H 2022),
and panel(c)Spearman’sshows the corescolor
N2D or DCO was detected. Panel (b) shows the cores color coded by their evolutionaryTherankline
coefﬁcientsare shown in the fromlower leftof each panel.
−1.17stage± 0.13for α–Σand
2 , respectively.
simulations.
ﬁnda innotincrement
theprestellar
coded by their parental molecular cloud. The solid line in both ﬁguresturbulenceshows the linear
regression toWe
all thepoint
the signiﬁcantplot, gives a slopeof −0.61in± 0.06;and thevelocity dispersionnt
s tocores,
that thegas within the core traced by these deuterated molecules is not yetgray shadowed area shows the 1σ conﬁdence interval for the ﬁt. Theprotostellar
Spearman’s rank
test suggesting
returns a coefﬁcientof rdenses = −0.68.
severely affected by turbulence injected from outﬂow activity at the early evolutionary stages traced in ASHES. The
most massive cores are strongly self-gravitating and have greater surface density, Mach number, and velocity
10
dispersion than cores with lower masses. Dense cores do not havent
signiﬁcant velocity
shifts relative to their lowsdensity envelopes, suggesting that dense cores are comoving with their envelopes. We conclude that the observed coreproperties are more in line with the predictions of clump-fed scenarios rather than with those of core-fed scenarios.

prestellar σ <1.5c , protostellar

prestellar

prestellar

prestellar σ <1.0c , protostellar

protostellar
Uniﬁed Astronomy Thesaurus concepts: Infrared dark clouds (787); Star forming regions (1565); Star formation
1.33à1.47(1569); Massive stars (732); Protostars (1302); Interstellar line emission (844); Interstellar medium (847);<, >, =Protoclusters (1297)
aG=πGΣ/5 aK=σtot2/R
Supporting material: machine-readable tables
protostellar
1. Introduction

High-mass stars (M  8 Me) are mainly responsible for thechemical enrichment and kinetic energy injection into theinterstellar medium (ISM)of galaxies (Kennicutt 1998; McKee& Ostriker 2007; Zinnecker & Yorke 2007). A great progress has
been made in investigating the basic properties of high-mass star-called a prestellar core. A prestellar core has not yet formed any
central protostellar object and is on the verge of gravitational
collapse (Ward-Thompson et al. 1994; Redaelli et al. 2021).
Prestellar cores represent the starting point in the starformation process. Different high-mass star formation theories
predict very different initial conditions for the prestellar cores.
In the core-fed or core-accretion models, a molecular cloud4.5 × 10−114),
and 0.56. On
he correlation= 0.88, and p(0.35 ± 0.01)
lope between
to intrinsic
and/or cores are obtainedof telescopes.
clumps and/ers (i.e., NH3,
nclude which

between σobse (Figure 10),
er is expected
and the latterogorov 1941;r results also
investigationt could breakmical range inCores andon the Coresf the clumps,
sity, velocity
mpact on the
any correlan coefﬁcientsthe cores.
mass of the= 0.50, and pation between
e value of the

TheALMASurvey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). VIII.
Dynamics of Embedded Dense Cores
Shanghuo Li1 , Patricio Sanhueza2,3 , Qizhou Zhang4 , Garay Guido5 , Giovanni Sabatini6 , Kaho Morii2,7 , Xing Lu8 ,Daniel Tafoya9 , Fumitaka Nakamura2,3 , Natsuko Izumi10 , Ken’ichi Tatematsu2 , and Fei Li111

Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany; shanghuo.li@gmail.com, li@mpia.de
National Astronomical Observatory of Japan, National Institutes of Natural Sciences, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan3
Department of Astronomical Science, SOKENDAI (The Graduate University for Advanced Studies), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
4
Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
5
Departamento de Astronomía, Universidad de Chile, Las Condes, Santiago, Chile6
INAF—Istituto di Radioastronomia—Italian node of the ALMA Regional Centre (It-ARC), Via Gobetti 101, I-40129 Bologna, Italy
7
Department of Astronomy, Graduate School of Science, The University of Tokyo, 2-21-1, Osawa, Mitaka, Tokyo 181-0015, Japan
8
Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030, People’s Republic of China
9
Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala, Sweden
10
Academia Sinica Institute of Astronomy and Astrophysics, 11F of AS/NTU Astronomy-Mathematics Building, No.1, Section 4, Roosevelt Road, Taipei 10617,
Taiwan11
School of Astronomy and Space Science, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, People’s Republic of China
Received 2023 January 1; revised 2023 March 16; accepted 2023 March 17; published 2023 June 2
2

)

1/2 (

GMC

⾒

)

Larson1/3 (⾒Abstract
We present dynamical properties of 294 cores embedded in twelve IRDCs observed as part of the ASHES Survey.
Protostellar cores have higher gas masses, surface densities, column densities, and volume densities than prestellar
cores, indicating core mass growth from the prestellar to the protostellar phase. We ﬁnd that ∼80% of cores with virial
parameter (α) measurements are gravitationally bound (α < 2). We also ﬁnd an anticorrelation between the mass andthe virial parameter of cores, with massive cores having on average lower virial parameters. Protostellar cores are
more gravitationally bound than prestellar cores, with an average virial parameter of 1.2 and 1.5, respectively. The
Figure 10. Observed velocity dispersion σobs as a function of the radius. From++observed
cores, nonthermal
clumps and velocity dispersion (from N2D or DCO ) is consistent with simulations in which turbulence isupper to bottom, panels show the σobs vs. radius for dense
whereas the core-to-core velocity dispersion is neither in agreement with driven nor decaying
dense core, and GMCs down to core, respectively. Thecontinuously
blue solid lineinjected,shows
the linear regression to all the points in the plot, and thegray shadowedarea
turbulencesimulations.
We ﬁnd a not signiﬁcant increment in the line velocity dispersion from prestellar toshows the 1σ conﬁdence interval for the ﬁt. The bestﬁt returns slopes
protostellar
cores,ofsuggesting that the dense gas within the core traced by these deuterated molecules is not yet
0.24 ± 0.08, 0.46 ± 0.01, and 0.35 ± 0.01 for upper, middle, and bottom
severely affected by turbulence injected from outﬂow activity at the early evolutionary stages traced in ASHES. The
panels, respectively. The Spearman’s rank coefﬁcients between observed
mostin massive
velocity and radius are presented in the lower right cornereach panel.cores
The are strongly self-gravitating and have greater surface density, Mach number, and velocity
0.38
dispersion
thanwith lower masses. Dense cores do not have signiﬁcant velocity shifts relative to their low∝ Rcores
black dashed line shows the the original Larson relation
with σobs(Larson 1981), and the red dashed line is the revised density
Heyer &envelopes,
Brunt (2004)suggesting that dense cores are comoving with their envelopes. We conclude that the observed core
relation with σobs ∝ R0.56.
sunproperties are more in line with the predictions of clump-fed scenarios rather than with those of core-fed scenarios.

2-3

6

core-fed : >30 M
Uniﬁed Astronomy Thesaurus concepts: Infrared<13 (rM=sun
⾒ dark clouds (787); Star forming regions (1565); Star formation−0.76, and p-value = 0.004),
core’s virial parameter(1569); Massive stars (732); Protostars (1302); Interstellar line emission (844); Interstellar medium (847);
suggesting that, at a higher surface density, clumps encompass
Protoclusters(1297)
clump-fed(α<0.5,,), global hierarchical(more gravitationally :bound cores within it.
There is no
Supporting
material:
machine-readable
tablescorrelation between the number of embedded cores
theMgas
R0-3=and) 0.89),inertial inflow ()
and p-value
clump velocity dispersion (r = −0.05,
α>0.5
15
1. Introduction
called a prestellar core. A prestellar core has not yet formed any prestellar
protostellar object and is on the verge of gravitational
R1.89responsible for the centralτ al. 1994; Redaelli et al. 2021).
) are mainly
High-mass stars (M M
8M
gascollapse (Ward-Thompson etflow
chemical enrichment and kinetic energy injection into the
Prestellar cores represent the starting point in the staràcore-fed
clump-fed
interstellar medium (ISM)of galaxies (Kennicutt 1998; McKee
formation process. Different high-mass star formation theoriessse& Ostriker 2007; Zinnecker & Yorke 2007). A great progress has
been made in investigating the basic properties of high-mass star-predict very different initial conditions for the prestellar cores.
In the core-fed or core-accretion models, a molecular cloudA Large Double-ring Disk Around the Taurus M Dwarf J04124068+2438157
Feng Long (龙凤)1,2,31 , Bin B. Ren (任彬)3,4,5 , Nicole L. Wallack6,7 , Daniel Harsono8 , Gregory J. Herczeg (沈雷歌)9 ,Paola Pinilla10 , Dimitri Mawet5,11 , Michael C. Liu12 , Sean M. Andrews2 , Xue-Ning Bai13 , Sylvie Cabrit4,14 ,Lucas A. Cieza15,16 , Doug Johnstone17,18 , Jarron M. Leisenring19 , Giuseppe Lodato20 , Yao Liu21, Carlo F. Manara22 ,Gijs D. Mulders23,24 , Enrico Ragusa25 , Steph Sallum26 , Yangfan Shi9 , Marco Tazzari27 , Taichi Uyama28,29,30 ,Kevin Wagner19,31 , David J. Wilner2 , and Jerry W. Xuan5
1

Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA; fenglong@arizona.edu
2Center for Astrophysics | Harvard & Smithsonian, 60 Garden St., Cambridge, MA 02138, USA
Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, F-06304 Nice, France
4
Université Grenoble Alpes, CNRS, Institut de Planétologie et d’Astrophysique (IPAG), F-38000 Grenoble, France
5
Department of Astronomy, California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125, USA
6
Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC 20015, USA
7
Division of Geological & Planetary Sciences, California Institute of Technology, MC 150-21, 1200 East California Boulevard, Pasadena, CA 91125, USA
8
The Department
AstrophysicalJournal,949:272023 May
20 Taiwan
Long
Institute of Astronomy,of Physics,
National
Tsing (14pp),
Hua University,
Hsinchu,
9Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, Peopleʼs Republic of China
10
Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK
11Long
et al. of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA
Jet Propulsion Laboratory, California
Institute
12
Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA
13
Institute for Advanced Study and Department of Astronomy, Tsinghua University, 100084, Beijing, Peopleʼs Republic of China
14
Sorbonne Université, Observatoire de Paris, Université PSL, CNRS, LERMA, F-75014 Paris, France
15
Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Av. Ejercito 441, Santiago, Chile
16
Millennium Nucleus on Young Exoplanets and their Moons (YEMS), Chile
17
NRC Herzberg Astronomy and Astrophysics, 5071 West Saanich Rd, Victoria, BC, V9E 2E7, Canada
18
Department of Physics and Astronomy, Universityof Victoria, Victoria,
BC, V8P
5C2,(14pp),
Canada 2023 May 20
The AstrophysicalJournal,949:2719
Steward Observatory, University of Arizona, 933 N Cherry Ave, Tucson, AZ 85721, USA
20
Dipartimento di Fisica, Universita Degli Studi di Milano, Via Celoria, 16, I-20133 Milano, Italy
21
Table 1
Purple Mountain Observatory & Key Laboratory for Radio Astronomy, Chinese Academy of Sciences, Nanjing 210023, Peopleʼs Republic of China
22
Dust Disk Model Results
European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München, Germany
23
Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Av. Diagonal las Torres 2640, Peñalolén, Santiago, Chile
24
Ring
Ring Location
Ring Width (σ)
incl.
PA
ΔR.A.
Millennium InstituteforNumber
Astrophysics, Chile Flux
25
Univ Lyon, Univ Lyon1, Ens de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon(mJy)
UMR5574, F-69230 Saint-Genis-Laval,
France (″)
(″)
(°)
(°)
(″)
26
Department of Physics and Astronomy, University of California, Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697-4575, USA
27#1(B70)±0HA
0.3 Cambridge,
0.472
0.038 ± 0.006
16.0 ± 1.1
122.6 ± 4.3
0.003 ± 0
Institute of Astronomy, University of Cambridge,
Madingley Road,3.3
CB3UK± 0.004
28
Infrared Processing and Analysis Center, California Institute of Technology,
Pasadena,
CA 91125, USA#2(B116) 1200 East California
12.7 ± 0.3Boulevard,0.782± 0.002
0.058 ± 0.003
29
NASA Exoplanet Science Institute, Pasadena, CA 91125, USA
30
National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
In the ﬁtting,
we assumed
the same
Received 2023 January 30; revised 2023 March Note.
16; accepted
2023 March
20; published2023inclination,
May 24 position angle, and phase center offsets for both rings. The disk total ﬂux should bradial drift
M dwarf
2MASS J04124068+2438157, 149 pc, M3.5
ALMA: 1.3 mm (0.06"), CO
3 (0.2", 0.3 km/s),
3

The Astrophysical Journal, 949:27 (14pp), 2023 May 20

5.7au 8.6 au

Keck/NIRC2: L' (3.8 µm)

i=16 deg, PA=122.7 deg
70, 116 au
τ~0.03-0.04 (15-20 K)
2

recent SMA observation suggests a total ﬂux of 20 ± 2 mJy (Liu, Terada et al., private comm.)

Abstract
through Hankel transformation (Pearson 1999) and sampled at(Birnstiel et al. 2018), we calculate the dPlanet formation imprints signatures on the physical structures of disks. In this paper, we present high-resolution
and 9.6 ± 0.2 M⊕ for B70 and B1
thesame
observed
spatialfrequencies.
The
comparisonof(∼50 mas, 8 au) Atacama Large Millimeter/submillimeter Array observations of 1.3 mm dust continuum and CO
continuum
disk size estimated from themodelJ04124068+2438157.
and data visibilities
usesdiskaconsists
Gaussian
likelihoodline emission toward the disk around the M3.5 star 2MASS
The dust
of only
2
2
2
85
±
0
003 (126.4 ± 4.5 au) whenis0
and( 
116
Gaussian
5.6 and 8.5 au,
two narrow rings at radial distances of 0 47 and 0 78 (∼70
$ r exp
D au),
2),withwhere
D σ∣ Vobs (uof
widths
k , vk )  Vmod (uk , vk )∣ wk ,
disk
size
deﬁnition
at 90% fractional lum
respectively. The width of the outer ring is smaller thantheestimatedpressurescale
heightby∼25%,
suggestingwith wk as the observed visibility weights. We assumed
dust trapping in a radial pressure bump. The dust disk size, set by the location of the outermost ring, is signiﬁcantly
80±
0002 at 68%, slightly
2017,
or
0
uniform priors
for betheexplained
ﬁtted byparametersand exploredthelarger (by 3σ) than other disks with similar millimeter luminosity,
which canan early formationofouter ring).
parameter
spacewith 50
and 5000
steps
local pressure bump to stop radial drift of millimeter dust
grains. Afterconsidering
thewalkers
disk’s physicalstructureand using a
Carlo (MCMC)
methodthe(emcee,
accretion properties, we prefer planet–disk interaction Markov
over dead Chain
zone or Montephotoevaporation
models to explain
4.2. Dust Versus Gas Distband
usingAs
Keck/NIRC2
observed dust disk morphology. We carry out high-contrast
imaging at theetL aal.
Foreman-Mackey2013).
the numbertoofsearchsteps largely
forsizepotential
doshapenotisidentify
any
above the5σ.andWithindust gap
theis
we forFigure 1. Top left: Continuum emission image of the 2M041240 disk at 1.3 mm with a beamof 0 06 ×young
0 05. Theplanets,
synthesizedbut
beam
shown
in theCO isotopologue
lines
Figure2. Topleft:source
Theexceeds
deprojectedbinnedthe
visibilities
asbetween
a function
oftwo
baseline
axisymmetricmodel. Top right:
Theweremodelinautocorrelation
time,
which
on rings,
the length
orderof the100data and theThreebottom-left corner of the panel. White contours are at levels of 3,5σ. Top right: Azimuthally averaged radial intensity proﬁle based on image to the left (after
1213. Analyses
gap/ring
reach a contrast level of ∼7 mag,intensity
constraining
the possible
planet of
below
∼2–4
MJup
proﬁle.
Comparisons
the data,
model,
andresidual in ofthetheimage
plane, constructed with thetions.
same tclean
parameters.
The
two
ring
location
CO
and
CO J
Emissionfromdeprojection). The Gaussian proﬁle in the bottom-right corner shows the FWHM of the synthesized beam. Bottom left: Continuum emission imageat 1.3 mmwith a Bottom:
steps,
theMCMC
are believed
to havereachedathat
anBottomapproximately
planetat with∼90black
au is35
likelychains
responsible
formationis shown in thesuggest
bottom rightcorner.
right:marked
AzimuthalSaturn-massintensity
beam size of 0 12. White contours are at levels of 3,5,7σ. The azimuthal angle conversion properties
out
in the residual
map,
contours
at 3 and 4σ. for
Thethecomparison
of ofdatatheand mode radial proﬁlesin the rightmost
to demonstra
seenis shownin channel
maps panel
withina narr90%

4σ
126 auwithin 10 au is unclear. For circumbinary disks, tidal forces
et al1
compositio
K
L⎛⎞Thoughdyna
tend to carve out an inner disk cavity,
size scales Disk
withAround the Taurus M Dwarf J04124068+2438157
A whoseLarge Double-ring
Td (r )  2 2 *(2) plane,its⎜ 4Qr (沈雷歌)
1,2,31 of two to threeangu
the binary semimajor axis, usuallyfactor
TSB ⎟ 9 ,millimeter
FengbyLonga(龙凤), Bin B. Ren (任彬)3,4,5 , Nicole L. Wallack6,7 , Daniel Harsono8 , Gregory J. Herczeg
10
established
Paola Pinilla, Dimitri Mawet, Michael C. Liu12 , Sean M. Andrews2 , Xue-Ning Bai13 , ⎝Sylvie Cabrit4,14⎠ ,calc(e.g., Figure
Artymowicz& Lubow 1994).
Therefore,
a 5,11stellar
17,18
19 The model radial20
21
22
2. Top left: The deprojected and binned visibilities as a function of15,16
baseline length for the data andthe axisymmetric model. Top right:
bottom pan
Lucas
A.
Cieza
,
Doug
Johnstone,
JarronM.
Leisenring,
Giuseppe
Lodato
,
Yao
Liu
,
Carlo
F.
Manara,intensity proﬁle.
Bottom: Comparisons
the data, model, and residual inthe
the imageplane, constructed with size)theThe two ring locations
are
23,24
25 same tclean parameters.
26
28,29,30
companion
within10 au of(approximately
coronagraphas a 3(e.g.,& Goldreich
1997;
Dullemond
et al. 2001), where 2020,iden
Gijs
D. Mulders
EnricoSallum, Yangfan
Shi9 , theMarco
Tazzari27 , Taichi
Uyama,
marked out in the residual map, with black contours at 3 and4σ. Thecomparison of data, andmode Ragusa
radial proﬁles ,isSteph
shown inthe rightmost
panel to Chiang
demonstrate
19,31
2
5
With a dus
match
in
the
centraldepression
in
the
image
with
the
observed
uv
coverage.
Kevin
Wagner,David
J.
Wilner
,
and
Jerry
W.
Xuan
The
AstrophysicalJournal,949:27(14pp),
2023
May
20
AstrophysicalJournal,May 20Long et al.
may not be able to explain our observed The
widecavityin949:27 (14pp), 2023 j∼90%
isTucson,theAZdisk
ﬂaringangle, L* is the stellar luminosity,and σSB thanuppe
Lunar and Planetary Laboratory, University of Arizona,
85721, USA;fenglong@arizona.edu
Center for Astrophysics| Harvard & Smithsonian, 60 Garden St., Cambridge,sustained
MA 02138,byUSA
Andrewsuse
thecollisionofplanetesimals
formedwithinthese
2M041240, unless the binary is on a very Université
eccentric
orbit.
of mid-M-dwarf
disks in Taurus d’Azur,
aroundstars of
is
the
Given
the
luminosityof (2021)
Côte d’Azur, Observatoire de la Côte
CNRS, Stefan–Boltzmann
Laboratoire
Lagrange, F-06304
Nice, constant.
Franceand(disks
would
then
quickly
migrateinward
get
lost
onto
the
et al.
modcomparison
Lupus,
Taurushigh-density
regions(Marinoand
2022;
Najitaet al.low2022).
On the),afactorofﬁvebrighterthanthemedianLmm
0.3–0.5Me
Université
Grenoble
Alpes,CNRS,
InstitutdePlanétologie
etd’Astrophysique(IPAG), F-38000 Grenoble, France
theFamous examples include HD142527 andIRAS
04158+2805,
ment).
Am
contrary,
those brightdisksUSAwith
inner
that departfromcentralstars.
This
processmightbeampliﬁed
if cavities
the diskhas
a midplanedead zone regio(∼3 mJy) California
in this Institutegroup. ofHowever,when
compared
to other
Department of Astronomy,
Technology,
MCthe249-17,1200 East
California
Boulevard,
Pasadena,
CA 91125,
central
star,
the
disk
radiuscorresponding
to
a
radii
of
2M
the
main USApopulation, especially those few around low-massEarthandknown
Planets Laboratory,
Carnegie Institution
for Science,
DC 20015,
WIS
with
dust
ingas
Taurus(LongWashington,
etdensityal.
where large cavities of ∼90 and 185
au in radii disksarebelieved
to substructureslowsurfacesothat
thegrainsgrow
largerand
drift
prolonged
timescatlargedDivision of Geological &2018;
Planetary
Sciences,
California
InstituteofTechnology,MC150-21,
1200
East
California
Boulevard,
Pasadena,
CA91125,
USA
the M*50− Lmmmight be(M* <temperature
15 K
is1 Mwellwithinau.relation,
Therefore,
these
Kurtovic et al. 2021) and other young
clusters (Huangof hostse) that drive
Instituteof Astronomy, Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
age
comparedbe carved by highly eccentric binaries at projected
separations
outliers
where
grain
growthwasinhibitedwithinpressure
faster.
This
islikelytrue
for2M041240,
asits
normaldust
cavitywiththen
et Instituteal. 2018a;
Cieza et al.
the diskaround
2M041240lies Peopleʼs Republic of China
Kavli
for Astronomy
and 2021),
Astrophysics,
PekingUniversity,
Beijing 100871,
substructuresareunlikelytoberelated
to
the
ice
lines
of
major
explainedbumps,
ifsomehowgrainsdid
notfragment
efﬁciently
inside
in
the
very
faint
end
(Figure4).
Inparticular,
we
note
that
the
Mullard Space
Science Laboratory,
University College
London, Holmbury
St Mary,
Dorking,
Surrey RH5 6NT,
UK already imply a low dust
forandat
emission
level
and
large
emittingarea
model grids,of ∼13 and 25 au, respectively (Price et al. 2018;
Ragusaetveryal.low-mass
above) andpressurebumps
Jet Propulsion
Laboratory,
Institute starsof Technology,
4800
Oak Grove Drive, thePasadena,
CA 91109,
USA due to the dust properties (such as
three disks
around California
(M5)
with
substructures
volatile
species(Zhanget al. 2015; Long et al. 2018). αIt −isviscosity
lost panethroug
Instituteazimuthal
foretAstronomy,
Universityof surface
Hawaii,
2680 density.
Woodlawn
Drive, Honolulu,
HI 96822, USA
in tcomposition)or because bouncing stops the effective growth.
comparable
to 2M041240.
in Kurtovic
al. (2021)
have Lmm
2021). Both of those cases show high-contrast
Institute for Advanced Study and Department of Astronomy, Tsinghua University, 100084, Beijing,
Peopleʼs
Republic of is
China
the
outer
Though2M041240anaveragesysteminthe
M−
L
AsSorbonnethese earlyhigh-resolution
disk surveys
havePSL,
often
selected F-75014 ice
worth
noticinglines can be very dynamic* andmm difﬁcult
bright inner
disk
93
are
Université,
Observatoire de Paris, Université
CNRS, LERMA, that
Paris, France
asymmetries in the dust ring, which is not Instituto
obviously
seen
in
the
out
that
the
plane,
its
dust
distribution
is
far
too
extended
for
its
given
brightdisks,
thedetection
of
dust
rings
in
2M041240suggestsde Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Av. Ejercito 441, Santiago, Chile
5.2.
OriginDisk
Substructures
our ALMA
imag
in theM* −toin faintmodel(e.g.,Owen
anda precise
midplanemillimeter
luminosity,
thusobtaining
sitting high above
the wellsubstructures
might
also beprevalentaroundcorr
Millennium
Nucleuson Young
Exoplanets
anddisks
their Moons(YEMS),
Chileof 2020),
2M041240 disk. Interestingly, recent models thatofthecircumshare
a com
NRC
Herzberg
Astronomy
andAstrophysics,
5071
West
SaanichRd,
Victoria,
BC,
V9E
2E7,
Canadaestablished scaling relation between Rmm and Lmm (see thelow-mass stars, emphasizing the potentially ubiquitous natureOne
intriguin∼2.1
Department
ofinside
Physics40and
Astronomy, high-resolution
Universityof Victoria,
V8P 5C2,
Canadatemperature
isBC,innerchallenging.
formingregbinary disk CS Cha suggest that the inclusion ofofadisk
planetWe
detecta Victoria,
widecavitydust etrings
peaking
Systematic
millimeter
substructures.
bottompanelof andFiguretwo
4, Andrews
al. 2018b;
Hendlerat
et al.
Steward Observatory, University of Arizona, 933 N Cherry Ave, Tucson, AZ 85721, USA
embeddedintheat thefain
imagingsurveys
of
faint
disks
are
neededtodetermine
if
2020,
as
a
3σ
outlierconsideringthederivedscatter
of
0.2
dex).
dust
Dipartimento
di Fisica,di Milano,
Celoria,16, I-20133
Italy width
The
of
ring
toau,oflocal
scale height surround
70Studiand
116Viacomparison
auwith
1σ Milano,
Gaussianwidth
5.6 pressureand 8.5 au,
the cavity
orbitingaroundcould
damp
theUniversita Degli
Figure 3. Azimuthally
averagedradial intensitythe
proﬁlesclose
for CO linesbinary
from thesubstructure
is common.
dust disk
size Republicof 126 of
the 2M041240 disk is larger
gaps and ringsM
MountainNanjinga 210023,
Peopleʼs
China
deprojected peak intensity maps. The shaded
regions mark thePurple
1σ scatterat Observatory & Key Laboratory for Radio Astronomy, Chinese Academy of Sciences, With
deproject(or ∼respectively,
in
theevaluate
2M041240
Whenconsideringa disk bumps.
population(hp) 2,canhelp
ifFigurearetrappedEuropeanSouthern
Observatory,Karl-Schwarzschild-Str.
D-85748
Garchingbei
München,Disks withlarge
inner cavities
are typicallybrighterandthan∼90%Germanyof grains
all disk.
Lupus
disks
(adoptingthein
R90pressure
results
fromcavityeacheccentricity
andreducethethedust-ring
asymmeradial bin divided by thesquare largely
root of the numberof beams across
4. Top: The
correlation
betweenstellarmass andluminosity at
density
waves
FacultaddeIngenieríayCiencias,
Universidad
AdolfoIbáñez,Av.
Diagonal
lasTorres2640,
Peñalolén,
Santiago,
Chile
large
and d
s
bin. The continuum emission proﬁle extracted from an image with the same
mm(2018b);
fordisk
2M041240
Taurus members(gray),
to ﬂaring
have a much shallower M* − Lpassively
Andrewset1.3al.thethe(orange),
Lupusothersampleis usedforand a collection
mm relation (equivalent
irradiateddisk,
midplanetemperature
O
R
/R
~2
MRS~0.6"
Thisisbecausealong-lived
gaspressurebump
issupposedtoMillennium
Institutefor
Astrophysics,
Chilebeam sizeCO
as the linemm
data al.
is shown
for comparison.
The colorticks atthe top of not Msafely
tries (Kurtovic
et2022).
Thus,
we
could
rule
out
of
disks
with
substructure
detection(blue,
seereferences
in
the
main
text);
radii,
thendiskmaterial,w
comparison
due to its higher
completeness of size measurein Pinillaal. 2018)
than thatfrom the full
diskUMR5574,
d used*−M
Univ Lyon, Univ Lyon1,
Ens
de Lyon,
CNRS, etCentrede Recherche
Astrophysiquede LyonF-69230 Saint-Genis-Laval,
Francethe ﬁgure denote the peak emission location for each tracer.
Bottom: The correlation
between disk millimeter luminosity and (90%atof ∼70
a be
given
radiusrReinescanbeapproximatedas:maincircu
M* −
Among
the trapped
ring
disks
with
similar
L be, the the
large
disk
populations.
With aninnercavityau,widerthe,Hall,
while
the
dust
can
in thethan
hpment).
Department of
Physics andAstronomy,
Universityof California,
Irvine,41292M041240
FrederickIrvine,CA92697-4575,
USA
2M041240 as a binary system, but a binary
alone
may
not
fractional)
radius.
The solidorangestarmmmarksconcentrated
disk of 2M041240,
andthrough
gap
Large
in
of Astronomy,
Universityof Cambridge,
Road, theCB3 0HA
Cambridge,
UKradiiof 2M041240
issimplydue
tothepresence
of
a
disk
ring
disk Institutedeviatessigniﬁcantly(fainterby ∼0.5Madingleydex) fromthe open orange star indicates the inner ring B70. The Lupus sample (inwithnarrower
regions(Dullemondal.
2018).
The
disk
pressure
1et4au.
Infrared Processing and Analysis Center, California Institute of Technology,
1200 East
California at
Boulevard,
Pasadena,
CA91125,
USA
revealedfretal.
2012).
Figu
39
1
explaintheobserveddiskmorphology.
purple),
as
well
as
the
scaling
relation(dashedline)
fromAndrews
et
al.
large
distance
of
110
The
faint
L
of
2M041240,
relation
reportedin
Pinillaetal.
(2018)
forinner
cavitydisks.
mm
new ALMA measurements when available (Ward-DuongNASA Exoplanet Science Institute, Pasadena, CA 91125, USA
KotherL*areringfor comparison.
lupus
sampleis adopted
better3 Rmmtionstend(e.g.,⎛ to2(2018b)⎞showndiskswith similar, could
be for its
k The
Td rmore
Dust
rings
are
widelyinterpreted
as Japan,pressure
bumps
trapTokyocompared
et al. 2018;
Akesonetemission
al. 2019; Longare
et al.found2019). Wewithin
alsodynamical
pertu
National
Astronomical
Observatory of
2-21-1
Osawa,that
Mitaka,181-8588, Japan
Deﬁcits
of
CO
the
inner
dust
coverageat thefaint
end.
The fainterBand
extended
disk
inkLupus
than
our
T
(
r
)

(
2
)
spatialreso
scaleheightcanbeestimated
as
h
=
,
where
is
the
d
explainedasenhancedgrain
growth
in
dust
rings
(as
discussed
=5.7,
10.7
Received 2023
January
revised 2023
16;particles
accepted 2023
20; published 2023
May
24
B
particles
locally
and30;eliminate
theMarch
loss of
fromMarchradialrecalculate the stellar13
masses using the spot models (with 50%
2Tis J16090141-3925119,
targetsurrounds
an M4 star.
Based
onau
the
⎜and/or⎟ ofp an innerwhichNdust
m palsoGM
angularseparatio
the
b
4
Q
r
accompani
above)
theabsence
disk
that
might
get
SB
*
peakswithatoura radial
cavity,spotwhere
coverage) theof SomersCO
et al. emission(2020) to be consistent
ALMA image in Ansdell et al. (2016, 2018), it remains unclear if it is a disk
drift. Indistance
an attempt toof
understand the observed stellar mass and
⎝
⎠
et
al.
2017
lost
throughradial
drift
with
the
lack
of
material
supply
from
with
a
large
cavityoraclosebinarysystem.
Boltzmann
constant,mistheproton
mass,
G
is
the
calculate thesig
adoption of 0.4 Me for 2M041240. The disk around 2M041240
disk brightness correlations, Pinilla etAbstract
al. (2020) found that thep(e.g.
closerthan
millimeter
dust.
Assumingthat thedust the physical0 36,falls
rare cases,
the outer region
due used
to pressure
trapping.
is worth pointing(The data
to create thisﬁgure areItavailable.)within in
the top10%theof millimeterbrightness
in thegroup
correlations
establishedonfrom
the full disk
sampleinanumberaring
angle,
φ=0.02
Planetformation
imprints signatures
structuresofdisks.
In
this
paper,
we
present
high-resolution
identify any
souconstant,
and= 2.3
is stands
the outmean
molecular
The com
LkCa(e.g.,gravitational
Chiang& Goldreich
Dullemond
et alsoal.
2001),
where
out that1997;
the innerring μof B70alone
asan outlier
rings were produced by embedded (∼50
planets,on Millimeter/submillimeter
themas, 8 au) based
Atacama Large
Array observations of 1.3 mm dust continuum and CO
Long
et
al
in
the
M
−
L
plane,
whichmaysuggest
that
the
two
rings
upper
cor
weightin (e.g.,
atomicUsing
aluminosity,
temperature
with limits
If neware only available at 0.89 mm, we scaledto
Substructures
also beenfound star
inj
disks
brown dwarfs
41 measurements
linethem
emission
towardthe diskhave
aroundthe M3.5
2MASS
The units.
dust
consistsof only
isaroundthe J04124068+2438157.
disk
ﬂaringangle,
L** disk
ismmthestellarandLupus
σproﬁlemay
SBstartrace
a
plan
dead
share a common
origin.
A
number
of
disks
in
the
proposed
Crida2020).et al. (2006),
wecalculatethecriterion
1.3 mm using
a spectral
index ofby
2.2zone(Andrews
ISO-Oph
2B, González-Ruilova
et al. 2020).
of ofstar-forming
regions can be well reproduced byuse
dustthe AMESand0.02
116 au),(awithconservative
Gaussian σ widths
5.6 and 8.5 au,
two narrow rings at radial distances of 0 47 and 0 78 (∼70
jtheStefan–Boltzmann=choice),thecorresponding
pressuretion 2M0
aroundforming
regionshow
similardeviations
inthemodels,
M* − Ldespite
plane
is
the
constant.
Given
the
low
luminosity
mmof
evolutionandparticletrappingadiscrepancy
respectively.
The
width
of
the
outer
ring
is
smallerthanestimatedpressurescale
heightby∼25%,
suggesting
required minimum
aL'gap 6in the gas surface
L' bandplanet mass to opendust
<3.9
MJup
characteristLamagnitudtheatthefainterend(see
Figure
4),
which
are
also
found
to
withcorresponding
sampleof brighttoinnercavitydisks.
In10.7this model
scaleheights
theradius
two
ring
locations
are
5.7
and
au, scenario
trapping in a radial pressure bump. The dust disk
set by thelocationtheoutermostring,
isthesigniﬁcantly
thesize,
centralstar,
theofatdisk
atheremidplaneFambesurroundM
dwarfs.
We
suspectthatmightﬂuxes
be area dueWISE
framework,thepredicted
lower
millimetertothe W1 and W
larger
(by
3σ)
than
other
disks
with
similarmillimeter
luminosity,
which
can
be
explained
by
an
early
formation
of
>10
au
ﬂuxes
in
b
populationofdisks
aroundlow-mass
stars
that
were
born
respectively.
While
the
width
(Gaussian
σ)
of
the
inner
ring
temperatureofconsidering
15
is disk’s
wellphysicalwithin
50 andau.of highTherefore,
these
whe
The
correlation
betweenstellarmass grains.
and diskAfter
luminosity
at K thecombined
effects
optical depth
and efﬁcientage
grainof 4.5
local pressureFigure
bump
stop
radialdrift ofmillimeter
dust
structure
34.toHTop:
50
41
Myr,
LkCa
15)
a
large
and
somehowbuiltapressure
bump
early
at
large
disk
1.3
mm
for
2M041240(orange),other
Taurusmembers(gray),
andacollection
A gas gap is opened if the disk satisﬁes M
the accretion
conditionof( Rwe prefer
1 1,) interaction overproperties,
deadiszone
or photoevaporation
to toexplainthelargersizes
in dustringsof(beyond
10 cm, “invisible”,related
the
outer
ring
B116
isdisks
narrower
thanthree(2020)
B70
comparable
tohmodelsM~0.3
M
qReplanet–disk
substructures
aretoKeck/NIRC2
be
to
the
ice
lines
major
pgrowthH substructure
besugcof disks
withdetection (blue, seereferencesin the maintext);unlikely
pl
pl
Jup
radii,
thenevolvedalong
a different
paththan theon the4
forreprese
L
a
band
using
to
searchobserved
dust
diskmorphology.
We
carry
out
high-contrast
imagingat
theat
millimeter
wavelengths,
Pinillaetal.
2020).
where H, RH, q, and Re are disk scale height, planet Hill radius,
Bottom: Theplanet-to-starcorrelation between disk millimeter luminosity and (90%
LkCa
di
main
− Lmm
as shown
by Zormpas
et al. (2022).
by∼25%,
providingstrongdust
trapping*al.
forpotential youngplanets,
notorange
identify
sourceabove
5σ. Within
the dust
gap
thetrend,
tworings,
weevidence
volatile(ZhangetMbetween
2015;
Long
et
al.istype2018).
It isin disks
p ofspecies
The
grain
growtheffectmoreofprominent
aroundof15 ∼
fractional)
radius. but
The dosolidstar any
marks
the h
disk
2M041240,
and
JWST/NIRCam
panel
of
Figure5
isothermal
mass ratio, and Reynolds number as rp 28p O , respectively.
Large
inner
cavities
were
the
ﬁrst
of
substructure
the openstarmag,
indicates
the inner ring
The Lupus(in∼2–4 MJup. Analysesof mass
the gap/ringreach a contrast
levelorangeof ∼7
constraining
the B70.
possibleplanetsample
below
lower
stars because of the higher fragmentation barrier
operatingthere.
2M041240
worth
noticing
that
ice
lines
can
be
very
dynamic
anddifﬁcult
revealed
frominitialsub-arcsecond
resolution
disk
observa2021
93 au),
our obse
purple),that
as wellas the scaling relation(dashed planetline) from
Andrews
al.
properties suggest
an approximately
Saturn-mass
at ∼90au isetlikely
responsible for theof thethatformation
can result
in larger grain sizes. Since the rings
of
1

2

3

4

5

6

7

8

9

10
11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

39

40

e-mail: gieser@mpe.mpg.de
Department of Chemistry, Ludwig Maximilian University, Butenandtstr. 5-13, 81377 Munich, Germany
Physical and chemical complexity in high-mass star-forming
4
Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, the Netherlands
3

regions with ALMA.

Received...; accepted...

I. Overview and evolutionary trends of physical properties
C. Gieser1, 2ABSTRACT, H. Beuther1 , D. Semenov1, 3 , A. Ahmadi4 , Th. Henning1 , and M. R. A. Wells1
1

rXiv:2304.07237v2 [astro-ph.GA] 24 Apr 2023

Max Planck
Institute for
Astronomy,
17,to
69117
Heidelberg,
Germany
Context. High-mass star formation is a hierarchicalprocessfromcloudKönigstuhl(>1 pc),clump(0.1-1pc) to core scales (<0.1 pc). Modern
2
Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany,
interferometers achieving high angular resolutions
at mm wavelengths allow us to probe the physical and chemical properties of thee-mail: gieser@mpe.mpg.de
3
Departmentof Chemistry,
Ludwig Maximilian
University, Butenandtstr. 5-13, 81377 Munich, Germany
gas and dust of protostellar cores in the earliest
evolutionary
formationphases.
4
Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, the Netherlands[ChatGPT]
ALMA

Aims. In this study, we investigate how physical properties, such as the density and temperature profiles, evolve on core scales

Received...; accepted...
through the evolutionary sequence during high-massstar formation ranging from protostars in cold infrared dark clouds to evolved
UCHii regions.
ABSTRACT
Methods. We observed 11 high-mass star-forming regions with the Atacama Large Millimeter/submillimeter Array (ALMA) at 3 mm
High-massandstar formationa hierarchical processlinefrom cloud(>1 pc), toclump (0.1-1pc) to corescalesfree-free(<0.1 pc). Modern
wavelengths. Based on the 3 mm continuumContext.
morphology
H(40)↵is recombination
emission,tracing
locationswith(↵)
interferometers achieving high angular resolutions at mm wavelengths allow us to probe the physical and chemical properties of theemission, the fragmented cores analyzed in gas
thisandstudy
areclassified
into
either“dust”or“dust+↵”
cores.
In
addition,weresolve
threedust of protostellar cores in the earliest evolutionary formation phases.
Aims.
In this study,
we isinvestigate
how physicalproperties, emission.
such as the density
temperature profiles,
evolveandon corescalescometary UCHii regions with extended 3 mmemissionthatdominatedby free-free
The andtemperature
structureradialthrough the evolutionary sequence during high-mass star formationq
13 ranging from protostars in cold infrared dark clouds to evolved
profiles (T ⇠ r ) are determined by modeling
emission of CH3 CN and CH3 CN with XCLASS and by using the HCN-toUCHiimolecularregions.
p
Methods.
We observed 11 high-massstar-forming
regions(nwith⇠ther Atacama
Millimeter/submillimeter
Array (ALMA)at 3 mm
HNC intensity ratio as probes for the gas kinetic
temperature.
The density
profiles) areLargeestimatedfrom the 3 mm
continuum
wavelengths. Based on the 3 mm continuum morphology and H(40)↵ recombination line emission, tracing locations with free-free (↵)
visibility profiles. The masses M and H2 columnN(Hare thencalculated
frominto
theeither
3 mmcontinuum2 )analyzed
emission,densities
the fragmented
cores
in thisstudy are classified“dust”dust
or “dust+↵”cores. In emission.
addition, we resolve three
23
cometary
UCHii
regionswithextended3
mmemissionthatisdominatedbyfree-free
emission.
The
and radial
Results. We find a large spread in mass and peak H2 column density in the detected sources ranging from 0.1 temperature
150
M structureand 10q
13(T ⇠ r ) are determined by modeling molecular emission of CH3 CN and CH3 CN with XCLASS and by using the HCN-to1026 cm 2 , respectively. Including the resultsprofiles
of
the
CORE
and
CORE-extension
studiestoincreasethesample
size,
we
find
evolutionHNC intensity ratio as probes for the gas kinetic temperature. The density profiles (n ⇠ r p ) are estimated from the 3 mm continuum
ary trends on core scales for the temperaturevisibility
power-law
q increasing
from
0.1 tofrom
infrareddark
to UCHii
regions,
profiles. index
The masses
M and H2 column
densities
N(H0.7then calculatedfromthe 3clouds
mm dust continuum
emission.
2 ) areWe finda large spreadin massandpeak
H2 column
density infor
the detectedsources rangingtrend.
from 0.1However,- 150 M and we
1023 while for the the density power-law index pResults.
oncorescales,
we
do
not
find
strongevidenceanevolutionary
1026 cm 2 , respectively. Including the results of the CORE and CORE-extension studies to increase the sample size, we find evolutionfind that on the larger clump scales throughout
theseevolutionary
phases thedensityflattensp ⇡infrared
2.2 to⇡ 1.2.
ary trends
on corescales for the temperature
power-lawindexprofileq increasingfrom 0.1 fromto 0.7 fromdarkpclouds
to UCHii regions,
while
for
the
the
density
power-law
index
p
on
core
scales,
we
do
not
find
strongevidenceforanevolutionary
trend.
Conclusions. By characterizing a large statistical sample of individual fragmented cores, we find that the physical properties,However,such aswefind that on the larger clump scales throughout these evolutionary phases the density profile flattens from p ⇡ 2.2 to p ⇡ 1.2.
the temperature on core scales and density Conclusions.
profile onByclump
scales,evolveeven
duringthe earliest
inproperties,
high-mass
characterizing
a largestatisticalsampleof individual
fragmentedevolutionarycores, we find that phases
the physicalsuch asthetemperatureon
core
scalesanddensity
profileon
clump
scales,evolveeven
duringtheearliest
evolutionary
phasesin high-massstar-forming regions. These findings provide observational constraint for theoretical models describing the formation of massive
stars.
star-forming regions. These findings provide observational constraint for theoretical models describing the formation of massive stars.
In follow-up studies we aim to further characterizechemicalof theregions
by analyzingtheamountof molecular
In follow-upthe
studies
we aim to properties
further characterize
the chemical
propertiesof the regions
by large
analyzing
the large amountof molecularlines detected
withtheALMA
in order toproperties
investigate howofthethe
chemicalproperties gasof theevolve
molecularduring
gas evolve
duringthe formationlines detected with ALMA in order to investigate
howchemicalmolecular
theformation
ofof
massive stars.
massive stars.
Key words. star formation – astrochemistry

Key words. star formation – astrochemistry

1. Introduction

tions at (sub)mm wavelengths allowing us to probe the dust andmolecular gas on core scales (<0.1 pc).
Massive stars form in the densest regions of molecular clouds

ALMA1 - Pulkovo Astronomical Observatory, Russian Academy of Sciences, Pulkovskoe sh. 65, St. Petersburg,
activity of CQ Tau on the time interval of
196140,Photometric
Russia2 - V.V. Sobolev Astronomical Institute, St. Petersburg State University, Universitetskii pr. 28, St. Petersburg,
125 years
198504, Russia
3 – Crimean Astrophysical Observatory, Russian Academy of Sciences, Crimea, Nauchny, Russia

V.P. Grinin1,2 , L.V. Tambovtseva1 , О.Yu. Barsunova1 , D.N. Shakhovskoy3

arXiv:2304.07115v1 [astro-ph.SR] 14 Apr 2023

arXiv:2304.07115v1 [astro-ph.SR] 14 Apr 202

Astrophysics, vol. 66, in press

1 - Pulkovo Astronomical
Observatory,
Russian to
Academyof Sciences,
Pulkovskoe
sh. 65,
St. Petersburg,
Abstract.
The star CQ
Tau belongs
the familyof UX
Ori typestars.
It has very
196140,Russiacomplex photometric behavior and complex structure of the circumstellar environment. In
2 - V.V. Sobolev Astronomical Institute, St. Petersburg State University, Universitetskii pr. 28, St. Petersburg,
our 198504,
paper Russia
we constructed the historical 125 years light curve of this star basing on the
publishedphotometricobservations.
It follows
that ofbesidesa randomcomponent
3 – Crimean
AstrophysicalObservatory, Russian
AcademySciences,
Crimea, Nauchny,
Russiacharacteristicof UX Ori type stars, the large amplitude periodic component with the 10 year period
is also present. Its existence was suspected earlier in [11]. New observations confirm its
reality. It points to an existence of the second component close to the star. The density
Abstract. The star CQ Tau belongs to the family of UX Ori type stars. It has very
waves andmatter flows caused by the companion motion lead to periodic changes in thecomplex photometric behavior and complex structure of the circumstellar environment. In
circumstellar
extinction and brightness of the star. This result is discussed in context of the
our paper we constructed the historical 125 years light curve of this star basing on the
recentobservationsof CQobservations.
Tau with highangularpublishedphotometric
It follows
that resolution.
besides a random component characteristicof UX Ori type stars, the large amplitude periodic component with the 10 year period
is also present. Its existence was suspected earlier in [11]. New observations confirm its
reality. It points to an existence of the second component close to the star. The density[ChatGPT]
waves and matter flows caused by the companion motion lead to periodic changes in thecircumstellar extinction and brightness of the star. This result is discussed in context of the
CQ Taurecent observations of CQ Tau with high angular resolution.

125

10

2

The role of previous generations of stars in triggering star formation andAccepted 2023 March 17. Received
2023 gasMarch
1; in original form 2022 October 21
driving
dynamics

ABSTRACT

School of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK

2015; Fogerty et al. 2016; Dobbs, Liow & Rieder 2020; Liow &Downloaded from https://academic.oup.com/mnras/article/521/4/5712/7086121 by KASI user on 19 June 2023

We present hydrodynamic
and2023magnetohydrodynamic(MHD)
simulationsof sub-galactic regions including photoionizing andAccepted
March 17. Received 2023 March 1; in originalform 2022 October
21
supernova feedack. We aim to improve the initial conditions of our region extraction models by including an initial population of
BSTR
ACTstars. We also investigateAthe
reliabilityof extracting regions in simulations, and show that with a good choice of region, results
We present hydrodynamic and magnetohydrodynamic (MHD) simulations of sub-galactic regions including photoionizing andare comparable with usinga largerregionforthe thedurationof our
Simulations
ofinitial
starpopulation
formation
on molecular cloudsupernova
feedack.
We aim to
improveinitial conditionsof oursimulations.
region extraction models
by including anofWe also investigate
the reliability
extracting
regions insimulations,showthenthat witha good choiceof region, results
scales typically start withstars.
a turbulent
cloudof gas,offrom
which
stars
formandandundergofeedback.
In reality, a typical cloudare comparable with using a larger region for the duration of our simulations. Simulations of star formation on molecular cloud
or region within a galaxyscales
mayalreadyor ofresidestarsIn reality,
containing
massive stars undergoingtypically
start withinclude,
a turbulent cloudgas, fromnear
which somestars formpopulationand then undergo of
feedback.
a typical cloud
or region within a galaxy may already include, or reside near some population of stars containing massive stars undergoing
feedback. We find the mainrole of a prior population is triggering star formation, and contributing to gas dynamics. Early time
feedback. We find the main role of a prior population is triggering star formation, and contributing to gas dynamics. Early timesupernova
from the initial
are importantin triggering new
formationand driving gas
on larger
scalessupernova from the initial
population
are population
importantin triggering
newstarstar
formation
andmotions
drivinggas
motions on larger scales
above 100 pc, whilst the ionizing feedback contribution from the initial population has less impact, since many members of theabove 100 pc, whilst the initial
ionizing
feedback
themodel.
initialpopulation
has less
impact,population
have clearedcontribution
out gas around themfrom
in the prior
In termsof overall star formation
rates
though, thesinceinitial many members of the
population
has agas
relatively
small effect,
andin
thethefeedback
doesmodel.
not for example
suppress ofsubsequent
star formation.
We find that rates though, the initial
initial population have clearedoutaroundthemprior
In terms
overallstar formation
MHD has a relatively larger impact than initial conditions, reducing the star formation rate by a factor of 3 at later times.
population has a relatively
small effect, and the feedback does not for example suppress subsequent star formation. We find that
Key words: hydrodynamics – radiative transfer – methods: numerical – ISM: clouds – galaxies: star formation – H II regions..
MHD has a relatively larger impact than initial conditions, reducing the star formation rate by a factor of 3 at later times.
1 I N T RO D U C T I O N
Key words: hydrodynamics– radiative transfer – methods: numerical– ISM:– galaxies:
star formation– H II regions..
Dobbs 2020). These clouds
not only missthe larger scale dynamics,
but[ChatGPT]

1 I N T RO D U C T I O NMost if not all star formation is influenced by larger scale processes
such as spiral arms, bars, feedback from massive stars, and large-scale
turbulence. Spiral arms induce converging flows (Roberts 1969),
bars drive gas flows towards the centres of galaxies (Krumholz,
Kruijssen & Crocker 2017; Seo et al. 2019) and are associated withlarge shearing motions (Sheth et al. 2000; Khoperskov et al. 2018),
whilst star formation is often supposed to be triggered within denseshells from H II regions and supernovae (e.g. Elmegreen & Lada
1977; Tieftrunk et al. 1997; Elmegreen 1998; Thompson et al. 2004;
Martins et al. 2010; Smith et al. 2010; Deharveng et al. 2012). Star
formation may thus be influenced by larger scale dynamics, as wellas the past star formation history of a region or a galaxy, whereby
previous generations of stars may be driving turbulence, or producing
shells and bubbles in the interstellar medium (ISM).
Incorporating these processes in numerical studies of star forma-

Most if not all star formation is influenced by larger scale processes
such as spiral arms, bars, feedback from massive stars, and large-scale
3 Spiral arms induce converging flows (Roberts 1969),
turbulence.
bars drive gas flows towards the centres of galaxies (Krumholz,
Kruijssen & Crocker 2017; Seo et al. 2019) and are associated withalso that regions of star formation may occur near to young massive
stars, with such stars undergoing ionization, winds and supernovae on
different timescales. Observationally, we see evidence for sequential
star formation (Fukuda & Hanawa 2000; Deharveng et al. 2003;
Preibisch & Zinnecker 2007), suggesting that later groups of clusters
of stars will be forming in or close to regions subject to feedback andwhere supernovae have already occurred.
An alternative approach is to simulate regions from larger scale
simulations at higher resolution (Dobbs 2015; Rey-Raposo, Dobbs& Duarte-Cabral 2015; Rey-Raposo et al. 2017; Seifried et al. 2017;
Shima, Tasker & Habe 2017; Bending, Dobbs & Bate 2020, 2022;
Rieder, Dobbs & Bending 2020; Ali 2021; Dobbs et al. 2022; Rieder
et al. 2022). These simulations have the advantage that they capture
the resolution necessary to follow low mass molecular clouds, starformation within molecular clouds, feedback processes and their

2015; Fogerty et al. 2016; Dobbs, Liow & Rieder 2020; Liow &Dobbs 2020). These not only miss the larger scale dynamics, butalso that regions of star formation may occur near to young massive
stars, with such stars undergoing ionization, winds and supernovae on
different timescales. Observationally, we see evidence for sequential
star formation (Fukuda & Hanawa 2000; Deharveng et al. 2003;
Preibisch & Zinnecker 2007), suggesting that later groups of clusters

Downloaded from https://academic.oup.com/mnras/article/521/4/5712/7086121 by

Nicholas P. Herrington,‹ Clare L. Dobbs and Thomas J. R. Bending

Advance Access publication 2023 April 6

Accepted 2023 March 31. Received 2023 MarchAccretion
31; in originalof
form
2022 December 19 large pebbles
aerodynamicallyHelong Huang (!!!)

and Chris W. Ormel‹

Department of Astronomy, Tsinghua University, Haidian DS, 100084 Beijing, China

Key words: accretion, accretion discs – planets and satellites: formation – planet–disc interactions – protoplanetary discs.

[ChatGPT]

Pebbles1 are (by definition) aerodynamically active, and tend tomove to regions of high pressure (Weidenschilling 1977). For smoothProtoplanetary discs around young stellar objects are found to emit atdisks, where the pressure gradient is radially negative, this results inmillimetre and submillimetre wavelengths (Looney, Mundy & Welch
their inward radial drift (Weidenschilling 1977). However, a local
2000; Andrews & Williams 2005; ALMA Partnershipet al.1 2015
; (byreversalof the pressure
distribution, e.g. active,
due to gapand
opening
Pebblesaredefinition)
aerodynamicallytendby to
1 I N T RO D U C T I O N
Ansdell et al. 2016). Most prominently, the Atacama Large Millimeplanets (Lin & Papaloizou 1986; Rafikov 2002; Zhu et al. 2014)
vevto
regionspressure(Weidenschilling
1977). Forsmoothter/submillimeter Array (ALMA) has revealedmo
the prealenceof disc of highor differential
accretion
flux at the edge ofan MRI
deadzone
substructure,rings,togaps,
spiralclumpsin the lastProtoplanetary discs around young stellar objects
arelikefound
emit
at arms, and(Varnière gradient& Tagger 2006
; Flock et al.
), e,willthis
likewiseshow indisks,
where
the pressure
is radially
ne2015
gativ
results
decade (ALMA Partnership et al. 2015; Andrews et al. 2018; Dongan imprint on the distribution of pebbles in discs. Pebbles are also
millimetre and submillimetre wavelengths (Looney,
Mundy & Welch
radial important
drift (Weidenschillingver,toamake
local
et al. 2018; Pérez et al. 2018; Andrews 2020their). Theseinward
observations
in driving planet growth.1977
First, ).
theyHoarewe
thought
light on the fundamental
physicalgoverning
disc pressure
2000; Andrews & Williams 2005; ALMAshed
Partnershipet al. 2015
; processes
up a largedistribution,
fraction, if not dominate,
the totalbudget inby
reversalof thee.g. due
to solid
gapmass
openingand planet formation. The leading interpretation is that the particles
protoplanetary
discs.
Butthemainreasonwhy
pebblesarefor
Ansdell et al. 2016). Most prominently, theresponsible
AtacamaforLarge
Millime& Papaloizou
1986; Rafikov 2002; Zhu et al.ideal2014)
the continuum emission areplanets‘pebbles’ –(Linparticles
planet formation is their mobility – the pebble reservoir in the outer
ter/submillimeter Array (ALMA) has revealed
thegrown
previnalence
that havethe disc ofoutdiscof (sub)micrometer-sizedgrains by accretion
disc may drift
to aidedge
planet growth
inner discregions.
or differential
fluxinwards
at theof anin the
MRI
dead
zone
coagulation (Smoluchowski 1916; Johansen et al. 2014; Drazkowska
Whenapebbledriftsacrosstheplanetorbit,
thegravityfromthesubstructure, like rings, gaps, spiral arms,et al.andclumps in the last
(Varnière & Taggerplanet
2006; Flock et al. 2015), will likewise show
2022; Miotello et al. 2022). The physical size of these particles
will attract the pebbles towards it. Without gas drag, most of
1 I N T RO D U C T I O N

Stokes

⾒
⾒

1

25

100

Downloaded from https://academic.oup.com/mnras/article/522/2/2241/7110421 by KASI user on 19 June 2023

Due to their aerodynamical coupling withgas, pebbles in protoplanetary discs can drift over large distances to support planet
Accepted 2023 March 31. Received 2023 March 31; in original form 2022 December 19
growth in the inner disc. In the past decade, this pebble accretion has been studied extensively for aerodynamically small
pebbles (Stokes number St < 1). HoweAver,accretion can also operate in the St > 1 mode, e.g. when planetesimals collisionally
BSTRACT
Dueprimordial
to their aerodynamical
couplingwith gas, pebbles
in protoplanetary
can drift
overstudy
large distances
to support
planetfragment to smaller bodies or when thegas disc
disperses.
This work
aims todiscs
extendtheof pebble
accretion
growth in the inner disc. In the past decade, this pebble accretion has been studied extensively for aerodynamically small
to these aerodynamically loosely coupled
particles. We integrate the pebble’s equation of motion, accounting for gas drag,pebbles (Stokes number St < 1). However, accretion can also operate in the St > 1 mode, e.g. when planetesimals collisionallyfragment toof
smallerbodies ordisc.
when theprimordialgas disc
disperses. This(workto extend theof pebbleof
accretion
stellar and planetary gravity, in the mid-planea laminarThe
accretion
probability!) isaims
calculated
asstudyfunction
Stokesto these aerodynamically loosely coupled particles. We integrate the pebble’s equation of motion, accounting for gas drag,number, disc pressure gradient index, planet
mass, and eccentricity. We find that for Stokes number above unity !(St) first rises,
stellar and planetary gravity, in the mid-plane of a laminar disc. The accretion probability (!) is calculated as function of Stokes
due to lower drift and aided by a large
atmosphericradius,untilandit eccentricity.
reaches We
a plateau
the efficiency
approaches
number,disc pressure capture
gradient index,
planet mass,find that forwhere
Stokes number
above unity !(St)first rises,due to lower drift and aided by a large atmospheric capture radius, until it reaches a plateau where the efficiency approaches
100 per cent. At high St, the plateau region
terminates as particles become trapped in resonance. These results are well described
100 per cent. At high St, the plateau region terminates as particles become trapped in resonance. These results are well describedby a semi-analytical ‘kick-and-drift’ modeland we ‘kick-and-drift’
also provide
fully
analyticalfor !. We
ourourmodelby a semi-analyticalmodel
and wealso provideprescriptions
fully analytical prescriptions
for !.apply
We applymodel to totheaccretion
of
∼30
µm
dust
particlesinadispersing
protoplanetary
andsecondary(CO-rich)debris
disc.
It
shows
that
the accretion of ∼30 µm dust particles in a dispersing protoplanetary and secondary (CO-rich) debris disc. It shows that such
such
physically small particles are mainly accreted as aerodynamically large Stokes number pebbles during the debris disc phase.
physically small particles are mainly Earth-massaccretedplanets
as aerodynamically
numberpebblesduringphase.
the debris disc phase.
may obtain ∼25 per centlargeof theirStokes
heavy elements
throughthis late accretion
Earth-mass planets may obtain ∼25 perof accretion,
their heavy
elements
throughthis formationlate accretion
phase.
Keycent
words:
accretion
discs – planetsand satellites:– planet–discinteractions – protoplanetary discs.

Downloaded from https://academic.oup.com/mnras/article/522/2/2241/7110421 by KAS

ABSTRACTJesús M. Jáquez-Domínguez1 , Roberto Galván-Madrid1 , Jacopo Fritz1 , Manuel Zamora-Avilés2 , Peter Camps3 ,Gustavo Bruzual1 , Maarten Baes3 , Yuxin Lin4 , and Enrique Vázquez-Semadeni11Instituto de Radioastronomíay Astrofísica,
Universidad
Nacional
Autónoma deMéxico, Morelia,
Michoacán
58089, México;
j.jaquez@irya.unam.mx
Simulated
Observationsof StarFormation
Regions:
Infrared
Evolutionof Globally
2
Instituto Nacional de Astrofísica, Óptica yCollapsing
Electrónica, Luis
E.
Erro
1,
72840
Tonantzintla,
Puebla,MéxicoClouds3
4

Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent, Belgium

1
1
2
Planck Institute forExtraterrestrial
Physics, Gießenbachstraße
Bayern,JesúsMax
M. Jáquez-Domínguez, Roberto Galván-Madrid, Jacopo Fritz1 1,85748, ManuelGarching,Zamora-Avilés,DeutschlandPeter Camps313
41
Received Gustavo
2023 February
28;Linaccepted
AprilVázquez-Semadeni
4; published 2023 June 13
Bruzual 16;, revised
Maarten2023
Baes March, Yuxin, and2023
Enrique
1,

Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia, Michoacán 58089, México; j.jaquez@irya.unam.mx
2
Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis E. Erro 1, 72840 Tonantzintla, Puebla, México
3
Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent, Belgium
4
Max Planck Institute for Extraterrestrial Physics, Gießenbachstraße 1,85748 Garching, Bayern, Deutschland
Received 2023 February 16; revised 2023 March 28; accepted 2023 April 4; published 2023 June 13

Abstract
A direct comparison between hydrodynamical simulations and observations is needed to improve the physics
included in the former and to test biases in the latter. Post-processing
radiative transfer and synthetic observations
Abstract
are now the standard
way to dobetween
this. hydrodynamical
We report onsimulations
the ﬁrstandapplication
SKIRT
radiative-transfer
code toA direct comparison
observationsof
is theneededto improve
the physics
includedintheformerandtotest
biasesinthelatter.
Post-processing
radiative
transfer
andsynthetic
observations
simulations of a star-forming cloud. The synthetic observations are then analyzed following traditional
are now the standard
waythatto dointhis.
reporton the ofﬁrsttheapplicationof the stellar
SKIRT radiative-transfer
code toobservational workﬂows.
We ﬁndtheWe
earlystagessimulation,
radiation is inefﬁcientin heating
simulations of a star-forming cloud. The synthetic observations are then analyzed following traditional
dust to the temperatures
are observed
clouds,thus the stellar
additionof aninterstellar
radiation ﬁeld isobservational thatworkﬂows.
We ﬁnd thatin
in Galactic
the early stagesof the simulation,
radiationis inefﬁcientin heating
dust
to
the
temperaturesthatareobserved
in
Galactic
clouds,thus
theadditionofaninterstellar
radiationﬁeld
isnecessary. The spectral energy distribution of the cloud settles rather quickly after ∼3 Myr of evolution
from thenecessary.
The
spectralenergydistribution
of
the
cloud
settlesratherquickly
after
∼3
Myr
of
evolutionfromthe
II regions
onset of star formation,butitsmorphology
continuestoevolve
for
∼8
Myr
due
to
the
expansionofH
onset of star formation, but its morphology continues to evolve for ∼8 Myr due to the expansion of H II regions
and the respective
creation
ofcreation
cavities,
ﬁlaments,
andandridges.
Modeling
synthetic
Herscheland therespectiveof cavities,
ﬁlaments,
ridges. Modelingsynthetic
Herschelﬂuxes withﬂuxes
one- orwith
two- one- or twocomponent
modiﬁedblackbodies
underestimates
total
dust
massesbyafactorof∼2.
However,
spatially
resolved
component modiﬁed blackbodies underestimates total dust masses by a factor of ∼2. However, spatially resolved
up to
aboutof70%
the intrinsicvalue.
value. Thismass”mass”
is locateda very coldﬁtting recoversﬁtting
up recovers
to about70%
theofintrinsic
This“missing“missing
is inlocatedin adust
very cold dust
component with temperatures below 10 K, which does not contribute appreciably to the far-infrared ﬂux. This
component withtemperatures
below 10 ifK,
does
notamounts.
contributeto the calibrations
far-infrared ﬂux. Thiseffectcould bias real observations
thiswhichdust exists
in large
Finally,appreciably
we tested observational
of
the
SFR
based
on
infraredﬂuxes
and
concluded
that
they
are
in
agreementwhencomparedtotheintrinsic
SFR calibrations
effect could bias real observations if this dust exists in large amounts. Finally, we tested observationalofthesimulation
averaged
over
∼100
Myr.
of the SFR based on infrared ﬂuxes and concluded that they are in agreement when compared to the intrinsic SFR
UniﬁedAstronomy
Thesaurusof the simulation
averagedover∼100concepts:
Myr. Star forming regions (1565); Interstellar medium (847); Interstellar
radiation ﬁeld (852); Computational methods (1965); Radiative transfer simulations (1967)
Uniﬁed Astronomy Thesaurus concepts: Star forming regions (1565); Interstellar medium (847); Interstellar
radiation ﬁeld (852); Computationaltransfer
simulations(1967)
1. Introductionmethods (1965); Radiative
about zero
to a few
percent in nearby
clouds (e.g., Evans et al.

[ChatGPT]

Star formation in the universe is fueled by the gas inmolecular clouds (MCs), but many questions remain unanswered. 1.
Only
in recent years has instrumentation been
Introduction
developed to allow us to perform multi-scale resolved studies
to localis
scales(for a review,see MotteStar formationandinconnect
the global
universe
fueledby thegas etinal.
2018).
An
important
topicofcurrent
researchistolink ourmolecular clouds (MCs), but many questions remain unanknowledge of star formation in the Milky Way and externalswered. Only inrecentyears
instrumentation
beengalaxies(e.g., thereviewhasby Kennicutt& Evans 2012).
MCs
obscureopticalstarlight
andthemselves
emit
from
neardeveloped to allow us to perform multi-scale resolved studies
infrared(near-IR)
radioa review,
wavelengths.
the lasttwoand connect global
to localscalesto (forsee InMotteet al.
decades, infrared (IR) surveys of the Galactic plane using2018). An important
topic ofsuch
current
research
is tohavelinkunveiled
ourspace telescopes
as Spitzer
and Herschelthestar-formation
contentofourGalaxy(e.g.,
Churchwell
et al.
knowledge of star formation in the Milky Way and external
2009;
Molinarietal.
2010).
Complementaryground-based
galaxies (e.g., the review by Kennicutt & Evans 2012). MCs

⾒2009; Forbrich et al. 2009) to >10% for the most active clouds
in the Milky Way (e.g., Galván-Madrid et al. 2013; Louvet
et al. 2014; Ginsburg et al. 2016). Several theoretical scenarios
about zero to a few percent in nearby clouds (e.g., Evans et al.
for MC evolution and star formation have been able to2009; Forbrichal. 2009) torestrictions>10% for(see,the e.g.,most active clouds
reproduce
a varietyet observational
Federrath& Klessen
2012;(e.g.,
Krumholz
et al. 2012; Vázquezin the MilkyWay
Galván-Madridet al. 2013; Louvet
Semadeni et al. 2019; Smith et al. 2020; Hennebelle et al.
et al. 2014; Ginsburg et al. 2016). Several theoretical scenarios2022). Among them, simulations of MCs that are under global
for MCevolutionappealing
and starhave been able tocollapseare particularly
for theformation
regime of massive
starformationinclusteredenvironments(e.g.,
Vázquezreproduce a variety observational restrictions (see, e.g.,
Semadeni et al. 2007; Heitsch & Hartmann 2008; Colín et al.
Federrath& Klessen
2012;
Krumholz
et 2019)
al. 2012; Vázquez2013;
Ibáñez-Mejíaet al. 2016;
Zamora-Avilés
et al.
Semadeni
et star-formingal. 2019;clumps
Smithappear
et al.
Hennebelle et al.
becausemassiveto be2020;
dominatedbyself-gravity(e.g.,
Liu
et
al.
2012;
Lin
et
al.
2016;
Liu
2017).
2022). Among them, simulations of MCs that are under global

I. Introducing and validating the method

Received XXX; accepted
YYY
Da EunKang1 , Victor F. Ksoll1 , Dominika Itrich3, 4 , Leonardo Testi5, 6 , Ralf S. Klessen1, 2 , Patrick Hennebelle7 , andSergio Molinari8

ABSTRACT
Universität Heidelberg, Zentrum für Astronomie, Institut
für Theoretische Astrophysik, Albert-Ueberle-Straße 2,
D-69120 Heidelberg, Germany
e-mail: kang@uni-heidelberg.de
2
Universität Heidelberg, Interdisziplinäres Zentrum für Wissenschaftliches Rechnen, Im Neuenheimer Feld 205,
D-69120 Heidelberg, Germany
3
European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany
4
Universitäts-Sternwarte, Ludwig-Maximilians-Universität, Scheinerstrasse 1, 81679 München, Germany
5
Alma Mater Studiorum Università di Bologna, Dipartimento di Fisica e Astronomia (DIFA), Via Gobetti 93/2, I-40129,
Bologna, Italy6
INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125, Firenze, Italy
7
Université Paris Cité, Université Paris-Saclay, CEA, CNRS, AIM, F-91191, Gif-sur-Yvette, France
8
INAF - Istituto di Astrofisica e Planetologia Spaziali, Via Fosso del Cavaliere 100, I-00133 Roma, Italy1

rXiv:2304.08398v1 [astro-ph.SR] 17 Apr 2023

rXiv:2304.08398v1 [astro-ph.SR] 17 A

Alma Mater Studiorum Università di Bologna, Dipartimento di Fisica e Astronomia (DIFA), Via Gobetti 93/2, I-40129,
Bologna, Italy
6
Spectral diclassification
young
starsFirenze,
using Italy
conditional invertible
INAF-Osservatorio Astrofisico
Arcetri, Largo E.of
Fermi
5, I-50125,
7neuralAIM,
networks
Université Paris Cité, Université Paris-Saclay, CEA, CNRS,
F-91191, Gif-sur-Yvette, France
8
INAF - Istituto di Astrofisica e Planetologia Spaziali, Via Fosso del Cavaliere 100, I-00133 Roma, Italy

Aims. We introduce a new deep learning tool that estimates stellar parameters (such as e↵ective temperature, surface gravity, andextinction) of young low-mass stars by coupling the Phoenix stellar atmosphere model with a conditional invertible neural network(cINN). Our networks allow us to infer the posterior distribution of each stellar parameter from the optical spectrum.
Methods. We discuss cINNs trained on three di↵erent Phoenix grids: Settl, NextGen, and Dusty. We evaluate the performance of
these cINNs on unlearned Phoenix synthetic spectra and on the spectra of 36 Class III template stars with well-characterised stellar
parameters.
Results. We confirm thatReceived
the cINNs
estimate
XXX; accepted
YYY the considered stellar parameters almost perfectly when tested on unlearned Phoenix
synthetic spectra. Applying our networks to Class III stars, we find good agreement with deviations of at most 5–10 per cent. The
ABSTRACTstars like late M-type stars, but we conclude that estimations ofcINNs perform slightly better for earlier-type stars than for later-type
We introduce
a newaredeepreliable
learning tool
thatallestimates
stellar parameters(such as e↵ective
temperature, surface
gravity,ande↵ective temperature andAims.
surfacegravityfor
spectraltypes within
the network’s
training
range.
extinction) of young low-mass stars by coupling the Phoenix stellar atmosphere model with a conditional invertible neural network
Conclusions. Our networks
time-efficient
tools
applicablelarge
Among the three networks, we(cINN).are
Our networks
allow us to infer
the posterior
distributiontoof eachstellaramounts
parameter fromof
theobservations.
optical spectrum.
Methods.
We
discuss
cINNs
trainedonthree
di↵erent
Phoenix
grids:
Settl,
NextGen,and
Dusty.
We
evaluatetheperformanceofrecommend using the cINN
trained on the Settl library (Settl-Net), as it provides the best performance acrossthe largest range ofthese cINNs on unlearned Phoenix synthetic spectra and on the spectra of 36 Class III template stars with well-characterised stellar
temperature and gravity. parameters.
Results. We confirm that the cINNs estimate the considered stellar parameters almost perfectly when tested on unlearned Phoenix

synthetic spectra. Applying our networks to Class III stars, we find good agreement with deviations of at most 5–10 per cent. The
Key words. Methods: statistical– Stars: late-type – Stars: pre-main sequence[ChatGPT]cINNs perform slightly better for earlier-type stars than for later-type stars like late M-type stars, but we conclude that estimations of

1. Introduction

cINNe↵ective temperature and surface gravity are reliable for all spectral types within the network’s training range.
Conclusions. Our networks are time-efficient tools applicable to large amounts of observations. Among the three networks, werecommend using the cINN trained on the Settl library (Settl-Net), as it provides the best performance across the largest range oftemperature and gravity.

⾒III

based on characteristic spectral features that vary depending on
Settl
the type of stars. Therefore, it is important to adopt the appropriate onmethodto spectral
the starunder
and to the observed
InSettl-Net
star-forming regions,1.itIntroduction
is massive stars that influence the based
characteristicfeaturesthat varyconsideration
depending on
the
type
of
stars.
Therefore,
itisimportant
to
adopt
the
approprisurrounding environmentIn energeticallyand dynamically during wavelength range.
star-forming regions, it is massive stars that influence the ate method to the star under consideration and to the observed
their short lifetime, but surrounding
the majority
ofenergeticallystars formed
in starenvironmentand dynamicallyduring wavelength range.
As the volume of accumulated observations ever-expand intheir short lifetime, but the majority of stars formed in starAs the volume of accumulated observations ever-expand informing regions are low-massstars similar to or less than the soforming regions are low-mass stars similar to or less than the soKey words. Methods: statistical – Stars: late-type – Stars: pre-main sequence

?

with
SOFIA/FIFI-LS:
Received February 14, 2023;
accepted
April 10, 2023 Physical conditions and UV fields

Ngân Lê1 , A. Karska1, 2?? , M. Figueira3, 1 , M. Sewiło4, 5, 6 , A. Mirocha7 , Ch. Fischer8 , M. Kaźmierczak-Barthel8 ,1 , W. J. Fischer10 , K. M. Menten2 , F. Wyrowski2 , C. König2 ,R. Klein9 , M. Gawroński1 , M. Koprowski1 , K. Kowalczyk
ABSTRACT
L. E. Kristensen11

Context. Far-infrared1 (FIR) line emission provides key information about the gas cooling and heating due to shocks and UV radiation
Institute of Astronomy, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka
˛5, 87-100

associated with the early
Toruń,stages
Poland of star formation. Gas cooling via FIR lines might, however, depend on metallicity.
2
Max-Planck-Institut
für Radioastronomie,
Aufdetermine
dem Hügel 69, the53121,
Bonn, Germany
Aims. We aim to quantify
the FIR line
emission andspatialdistribution of the CO rotational temperature, ultraviolet
3National Centre for Nuclear Research, ul. Pasteura 7, 02-093, Warszawa, Poland(UV) radiation field, 4 andHnumberdensity
towardtheembeddedclusterGy Greenbelt,
3–7 in MD
the20771,
CMa–l224
star-forming region, whose
2 and Stellar Astrophysics Laboratory, NASA Goddard Space Flight Center,
Exoplanets
USA
5
Research and Explorationin Space
Technology,
NASA Goddard
Spaceand
FlightCenter,Greenbelt,
MD 20771
metallicity is expected6 Center
to beforintermediate
betweenthatScienceof theandLarge
Magellanic
Cloud
the
Solar
neighborhood.
By comparing the
Department of Astronomy, University of Maryland, College Park, MD 20742, USA
total luminosities of CO
and [O Observatoryi] towardofGy
3–7 withUniversity,
values Orlafound
for lowandPoland
high-mass protostars extending over a broad range
7
Astronomical
the Jagiellonian
171, 30-244,
Kraków,
8
Deutsches
SOFIA
Institut,theUniversityof Stuttgart,Pfa↵enwaldring
29, 70569,
Stuttgartof metallicities, we alsoaim
toidentify
possiblee↵ectsofmetallicity
on
the
FIR
line cooling within our Galaxy.
9
SOFIA/USRA, NASA Ames Research Center, P.O. Box 1, MS 232-12, Mo↵ett Field, CA 94035, USA
Methods. We studied10SOFIA/FIFI-LS
spectra
GySan3–7,
covering
several
CO USAtransitions from J = 14 13 to 31 30, the OH doublet
Space Telescope Science
Institute,of
3700
MartinDr., Baltimore,
MD 21218,
0
11
BohrInstitute,
Centrefor theStar and
PlanetFormation,
University
Copenhagen,Øster covers
Voldgade 5-7,
at 79 µm, the [O i] 63.2Niels
and
145.5
µm,
and
[C ii]
158µm lines.
Theof fieldof viewa 201350⇥ 1Copenhagen,region with a resolution of
Denmark00
00⇠7 -18 .
Received of
February2023;Jaccepted
2023
Results. The spatial extent
CO 14,
high(Jup April
14)10,emission
resembles that of the elongated 160 µm continuum emission detectedwith Herschel, but its peaks are o↵set from the positions of the dense cores. The [O i] lines at 63.2 µm and 145.5 µm follow a similar
ABSTRACTpattern, but their peaks are found closer to the positions of thecores. The CO transitions from J = 14 13 to J = 16 15 areContext.
Far-infrared
lineaemission
provideskey information
about the gas ofcoolingand heating
shocks and UV radiation
detected throughout theclusterand (FIR)
show
medianrotationaltemperature
170±30
K due
ontoBoltzmann
diagrams. Comparisons to
associated with the early stages of star formation. Gas cooling via FIR lines might, however, depend on metallicity.
other protostars observedwith Herschel show a good agreement with intermediate-mass sources in the inner Galaxy. Assuming an
Aims. We aim to quantify the FIR line emission and determine the spatial distribution of the CO rotational temperature, ultraviolet
origin of the [O i] and(UV)highradiation
J CO
emissionin UV-irradiatedshocks,weGyobtained
pre-shockH2 numberof 104 -105 cm 3
field,and H2 number
density toward theCembeddedcluster
3–7 in the CMa–l224
star-forming
region, densities
whose
is expected
to be intermediate
Magellanic Cloud and the Solar neighborhood. By comparing theand UV radiation fieldmetallicity
strengthsof 0.1-10
Habingbetween
fieldsthat(Gof0 ).the Large
total luminosities of CO and [O i] toward Gy 3–7 with values
found for low- and high-mass protostars extending over a broad range
Conclusions. Far-IR ofline
observations
ongoing
formation
GyFIR3–7,
dominatedintermediate-mass Class 0/I young
metallicities,
we also aimreveal
to identify
the possiblestare↵ectsof metallicityinon theline coolingwithin ourby
Galaxy.
Methods.
We
studied SOFIA/FIFI-LS spectraof Gyline
3–7, covering
several
CO transitions
from J = 14 trend
13 to 31with
30, theOH doublet luminosities of thestellar objects. The ratioofmolecular-to-atomic
far-IRemissionshowsadecreasing
bolometricat 79 µm, the [O i] 63.2 and 145.5 µm, and the [C ii] 158 µm lines. The field of view covers a 20 ⇥ 10 region with a resolution of
protostars. However, it⇠700does-1800 . not indicate that the low-metallicity has an impact on the line cooling in Gy 3–7.

Xiv:2304.08127v1 [astro-ph.GA] 17 Apr 2023

arXiv:2304.08127v1 [astro-ph.GA] 17

Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218, USA
Niels Bohr Institute, Centre for Star and Planet Formation, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen,Denmark
Far-infrared line emission from the outer Galaxy cluster Gy 3–7
11

Results. The spatial extent of CO high J (Jup14) emission resembles that of the elongated 160 µm continuum emission detectedwith Herschel,but its peaks
are o↵set fromthe positionsof theoutflows
dense cores. –The[O i] lines
at 63.2 µm and 145.5 µm follow a similar
Key words. stars:formation– stars:
protostars– ISM:
jets andISM:
molecules[ChatGPT]
pattern, but their peaks are found closer to the positions of the cores. The CO transitions from J = 14 13 to J = 16 15 aredetected throughout the cluster and show a median rotational temperature of 170±30 K on Boltzmann diagrams. Comparisons to
FIR
Gy 3-7other protostars observed with Herschel show a good agreement with intermediate-mass sources in the inner Galaxy. Assuming an
origin of the [O i] and high J CO emission in UV-irradiated C shocks, we obtained pre-shock H number densities of 10 -10 cm
COand UV radiation field strengths of 0.1-10 Habing fields H2(G ).
1. Introduction
ter the physical conditions and chemistry of their environment,
Conclusions. Far-IR line observations reveal ongoing star formation in Gy 3–7, dominated by intermediate-mass Class 0/I young
FIR
stellar objects. The ratio of molecular-to-atomic far-IR line emission
shows ona decreasing
with bolometricluminositiesof the Frank et al. 2014). Nonevenclumptrendscales(Arceet al. 2007;
protostars.
However,
it
does
not
indicatethatthelow-metallicity
has
animpactontheline
coolingin
Gy
3–7.
During the earliest stages of star formation, the gravitational dissociative shock waves develop as the jets (and winds) interGy
3-7words. stars:formationstars:ejection
protostars – ISM:
jets and outflows – ISM: molecules
collapse of dense cores isKeyaccompanied
by– anof bipo2

4

5

3

0

lar jets originating from the resulting protostars, which may al-

act with the surrounding medium (Kaufman & Neufeld 1996a;

e-mail: zgyin@nao.cas.cn; ljz@nao.cas.cn
Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM, F-91191, Gif-sur-Yvette, France
Properties of the dense cores and filamentarye-mail: alexander.menshchikov@cea.fr

structures in the Vela C molecular cloud ?

Received / Accepted

Xue-Mei Li1, 2 , Guo-Yin Zhang2 , Alexander Men’shchikov3 , Jin-Zeng Li2 , Chang Zhang2 , and Zhong-Zu Wu1

ABSTRACT
College of Physics, Guizhou University, Guiyang 550025,
PR China
National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100101, PR Chinae-mail: zgyin@nao.cas.cn; ljz@nao.cas.cn
The initial and boundary
conditions of the Galactic star formation in molecular clouds are not well understood. In an e↵ort to shed3
Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM, F-91191, Gif-sur-Yvette, France
new light on this long-standing
problem, we measured properties of dense cores and filamentary structures in the Vela C moleculare-mail: alexander.menshchikov@cea.fr
cloud, observed withReceived
Herschel.
We used the hires algorithm to create high-resolution surface densities (11.700 ) from the Herschel/ Accepted12

Xiv:2304.10863v1 [astro-ph.GA] 21 Apr 2023

04.10863v1 [astro-ph.GA] 21 Apr 2023

3

multiwavelength dust continuum. We applied the getsf extraction method to separate the components of sources and filaments fromeach other and their backgrounds, before detecting, measuring,and cataloging the structures. The cores and filamentary structures
ABSTRACTconstitute 40% of theThe
totalmass of Vela C, most of the material is in the low-density molecular background cloud. We selected 570
initial and boundary conditions of the Galactic star formation in molecular clouds are not well understood. In an e↵ort to shedreliable cores, of which149
areprotostellar
and 421
are ofthe
starless
Almost78%421) of the starless cores
new light onthisthelong-standing
problem,cores
we measured
properties
dense
cores andcores.
filamentary
structuresin the(329Vela Cofmolecular00
cloud,
observed
with
Herschel.
We
used
the
hires
algorithm
tocreatehigh-resolution
surfacedensities
(11.7
)
from
the
Herschel
were identified with thegravitationally bound prestellar cores. The exponent of the CMF (↵ = 1.35) is identical to that of the Salpeter
multiwavelength dust continuum. We applied the getsf extraction method to separate the components of sources and filaments from
IMF. The high-resolution
surfacedensity
image
determineand subtract
backgrounds
measuresizes of the structures.
each otherand theirbackgrounds,
beforehelped
detecting,us
measuring,and cataloging
the structures.
The cores and andfilamentary
structures
constitute40%atof thetotal onemass of
Vela thatC, mostof the material
the low-density
backgroundcloud. We
selected570
We selected 68 filaments
with
least
side
appearednotis inblended
withmolecular
adjacent
structures.
Thefilament
widths are in thereliable cores, of which 149 are the protostellar cores and 421 are the starless cores. Almost 78% (329 of 421) of the starless cores
range of 0.15 pc to 0.63
pc, andwith
havea medianboundvalueof Wcores.
= 0.3± 0.11ofpc.
The(↵surface
densities
were identified
the gravitationallyprestellar
The exponent
the CMF= 1.35) is identicalto thatofof filaments
the Salpeter are well correlated
IMF. linear
The high-resolution
surfacedensityuncertainties
image helped us determine
subtract backgrounds
measure sizesof the structures.
with their contrasts anddensities.
Withinof the andfilament
instabilityandcriterion,
many
filaments (39) may well be
We selected 68 filaments with at least one side that appeared not blended with adjacent structures. The filament widths are in theboth supercritical andrange
subcritical.
of filaments
maypc.definitely
be considered
supercritical,
of 0.15 pc to A
0.63large
pc, andfraction
have a medianvalue of W = (29)0.3 ± 0.11
The surface densities
of filaments arewell correlated in which are found
with
their
contrasts
andlineardensities.
Withinuncertainties
ofthefilament
instability
criterion,
many
filaments(39)
may well be
94 prestellar cores, 83 protostellar cores, and only 1 unbound starless core. Taking into account the uncertainties,
the supercriticalboth supercritical and subcritical. A large fraction of filaments (29) may definitely be considered supercritical, in which are foundfilaments contain only94prestellar
andprotostellar
cores.
Our
findings
support
the
idea
that
there
existsadirectrelationshipbetween theprestellar cores, 83 protostellar cores, and only 1 unbound starless core. Taking into account the uncertainties, the supercriticalfilaments
contain only
prestellar
protostellar
Our findings
the idea that
there exists
a directrelationship between
CMF and IMF and thatfilamentsplay
a keyandrole
in thecores.
formationofsupport
prestellar
cores,
whichis consistent
withthethe previous Herschel
CMF and IMF and that filaments play a key role in the formation of prestellar cores, which is consistent with the previous Herschelresults.
results.

Key words. –stars:
formation– ISM:
clouds –structure
ISM: structure
submillimeter: ISM ISM
ISM:
clouds– ISM:– –submillimeter:[ChatGPT] Key words. stars: formationC
1. Introduction
tary structures with a wide range of sizes, densities, and morphologies that are indeed widespread in the molecular clouds570
1. Introduction Star formation takes place within molecular clouds (André et al. (Men’shchikov
tary structures
withwide rangeof sizes,
et al. 2010;
Li &aGoldsmith
2012; Schisano
et al. densities, and mor2014; Heyer & Dame 2015) that appear as blends of (round) 2020). Most dense cores are locatedCon the supercritical fila-40
phologies that are indeed widespread in the molecular clouds
sources, filamentary structures, large-scale background, small- ments, which suggests that the filaments can fragment into theStar formation takes place
withinmolecular
clouds(André
etal.
(Men’shchikov
al. 2010;
Li(Könyves& Goldsmith
scale
fluctuations,etc. Separationof the structural components, cores
which eventuallycollapse
into stars
et al. 2015).2012; Schisano et al.
0.15
pcthat0.63
pc
0.3 pcet2014; Heyer & Dame2015)
appearoffilaments(round)measurement,
and analysisof as
the blends
sources andareto improve
our understandingof the initial conditions
sources, filamentary thought
structures,large-scale
background,smallof star formation (cf. Bergin & Tafalla 2007; André et al. 2010).
scale fluctuations, etc. Separationof thestructural
Photometric surveysof thenearby (. components,
500 pc) molecular
cloudsandGalacticplane
withHerschel,covering
thermalare
farmeasurement, and analysis of the sources and filaments
IR and sub-millimeter continuum in five bands between 70 andThedetailedMost
fragmentation
mayarebe controlled
by the2020).
densemannercores
locatedonlin-the supercritical filaear density, geometrical bending, continued accretion of gas, andments,fields
whichthat etthe
filaments
can fragment into themagnetic
in thesuggests
filaments (Zhang
al. 2020).
The mass
distributionof starseventuallyat their birth is
known as thestellarinitialcores whichcollapse
intostars(Könyves et al. 2015).
mass function (IMF) (Salpeter 1955; Chabrier 2005). Since stars
The detailed fragmentation manner may be controlled by the linare born in the dense cores, studies of the core mass function

7

Dipartimento di Fisica, Universitá degli Studi di Milano, via Celoria 16, 20133 Milano, Italy
Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
9
A spectacularfrom thedebrightOrion
proplyd:
Instituto de Astrofísica e Ciências
do Espaco,jet
Universidade
Lisboa,244–440
OAL, Tapada
da Ajuda,
1349-018 Lisboa, Portugal
8

The MUSE NFM view?

Received 10 November 2022 / Accepted
25 February
2023 1
1
2
A. Kirwan, C. F. Manara , E. T. Whelan , M. Robberto3,4 , A. F. McLeod5,6 , S. Facchini7 , G. Beccari2 ,A. Miotello2 , P. C. Schneider8 , A. Murphy1 , and S. Vicente9

ABSTRACT
Maynooth University Department of Experimental Physics,
National University of Ireland Maynooth, Maynooth Co. Kildare, Irelande-mail: andrew.miller@mu.ie
2European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748, Garching bei München, Germany
3
Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
4Space Telescope Science Institute, 3700 San Martin Dr, Baltimore, MD 21218, USA
5
Centre for Extragalactic Astronomy, Department of Physics, Durham University, South Road, Durham DH1 3LE, UK
6
Institute for Computational Cosmology, Department of Physics, University of Durham, South Road, Durham DH1 3LE, UK
7
Dipartimento di Fisica, Universitá degli Studi di Milano, via Celoria 16, 20133 Milano, Italy8
Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
9Instituto de Astrofísica e Ciências do Espaco, Universidade de Lisboa, OAL, Tapada da Ajuda, 1349-018 Lisboa, Portugal II
1

In this work we present the highest spatial and spectral resolution integral field observations to date of the bipolar jet from the Orion
proplyd 244–440 using Multi-Unit Spectroscopic Explorer (MUSE) narrow-field mode (NFM) observations on the Very Large Telescope (VLT). We observed a previously unreported chain of six distinct knots in a roughly S-shaped pattern, and by comparing themwith Hubble Space Telescope (HST) images we estimated proper motions in the redshifted knots of 9.5 mas yr 1 with an inclination
angle of 73 , though these quantities could not be measured for the blueshifted lobe. Analysis of the [Fe ] and [Ni II] lines suggests jet
3densities on the order of Received⇠105 10
cmNovember. We2022
proposethe 2023
observed S-shaped morphology originates from a jet launched by a smaller/ Accepted that
25 February
source with M? < 0.2 M in orbital motion around a larger companion of M? ' 0.5 M at a separation of 30–40 au. The measured
ABSTRACTluminosities of the knots using the [O I] 6300 Å and [S II] 6731
Å lines were used to estimate a lower limit to the mass-loss rate in111
91
present
the highest
spatialto dateof the bipolar driving
jet from the sources.
Orion
the jet of 1.3 ⇥ 10 M In
yrthis work
andwean
upper
limit
of and10spectral
M resolution
yr , integral
whichfieldisobservations
typical forlow-mass
While the brightness
proplyd 244–440 using Multi-Unit Spectroscopic Explorer (MUSE) narrow-field mode (NFM) observations on the Very Large Teleasymmetry between the redshiftedandblueshifted
lobes ischain
consistentirradiation,
furtheranalysisof the [Ni II] and [Fe II]
scope (VLT). We
observeda previously unreportedof six distinctwith
knots inexternala roughly S-shaped
pattern, andby comparing
themwith Hubble Space Telescope (HST) images we estimated proper motions in the redshifted knots of 9.5 mas yr 1 with an inclinationlines suggests that photoionizationof the jet is not likely to be a dominant factor, and that the emission is dominated by collisional
angle of 73 , though these quantities could not be measured for the blueshifted lobe. Analysis of the [Fe II] and [Ni II] lines suggests jet
5densitiesorder
cm 3 . We propose
the observed S-shaped
morphology
originatesa jet launchedby a smaller
excitation. The dynamical
age onofthethejetof ⇠10comparedto thethatanticipatedsurvival
timeof thefromproplyd
demonstrates
that photoevaporation
source with M? < 0.2 M in orbital motion around a larger companion of M? ' 0.5 M at a separation of 30–40 au. The measuredof the proplyd occurred prior
to jetandthatÅ thisactivesource.
twoto thepointssuggestluminositiesof thelaunching,knots using the [OI ] 6300and [S is
II ] still
6731 Åan
lines
were used
to estimateThesea lower limit
mass-loss
rate in that the envelope of the
111
91
the from
jet of 1.3the⇥ 10 majority
M yr andof
an upperlimit of 10
M yr , which
low-mass driving sources.
brightnessdoes not appear to impact
proplyd may shield the jetexternal
radiation,
andis typicalthat forphotoionizationof While
the theproplyd
asymmetry between the redshifted and blueshifted lobes is consistent with external irradiation, further analysis of the [Ni II] and [Fe II]
the ability of a star to launcha jet.that photoionization of the jet is not likely to be a dominant factor, and that the emission is dominated by collisionallines suggests
excitation. The dynamical age of the jet compared to the anticipated survival time of the proplyd demonstrates that photoevaporationof the proplyd occurred prior to jet launching, and that this is still an active source. These two points suggest that the envelope of the
proplyd may shield the jet from the majority of external radiation, and that photoionization of the proplyd does not appear to impact
the ability of a star to launch a jet.

Key words. ISM: jets and outflows – ISM: individual objects: Orion Nebula – stars: pre-main sequence – protoplanetary disks[ChatGPT]– stars: individual: 244-440
244-440
S
Key words. ISM: jets and outflows – ISM: individual objects: Orion Nebula – stars: pre-main sequence – protoplanetary disks– stars: individual: 244-440
6highproper motion,that induce a curvature in the jet (Bally &1. Introduction 10^5/cc
1.3 ×
10^(-9)Msun/yr
high10^(-11)
proper motion, that induce
a curvature in the jet (Bally &1. Introduction

Astrophysical jets are near-ubiquitous phenomena in the evolution of low- and intermediate-mass young stellar objects (YSOs,
Frank et al. 2014), and have similarly been observed in high-Astrophysical jets are near-ubiquitous phenomena in the evolution of low- and intermediate-mass young stellar objects (YSOs,
Frank et al. 2014), and have similarly been observed in highmass YSOs as well (Marti et al. 1993; McLeod et al. 2018).
The formation of clumpy, shock-heated condensations known as

Reipurth 2001; Raga et al. 2009); in binary systems, companions may induce warping in the inner disk, precession, or orbital
motion that causes a “wiggling” jet morphology (Masciadri &Raga 2002; Lai 2003; Murphy et al. 2021; Erkal et al. 2021;

Reipurth 2001; Raga et al. 2009); in binary systems, companions may induce warping in the inner disk, precession, or orbital
motion that causes a “wiggling” jet morphology (Masciadri &Raga 2002; Lai 2003; Murphy et al. 2021; Erkal et al. 2021;
Kirwan et al. 2022).
The exact mechanism of jet launching is not known, but cur-∗ Corresponding author. E-mail: sreelekshmimohan94@gmail.com

Modeling of thermal and non-thermal radio emission from HH80-81 jet

MS received 19 October 2022;SREELEKSHMI
accepted 7 MOHAN
March∗ ,2023
S. VIG and S. MANDAL
Indian Institute of Space Science and Technology, Thiruvananthapuram 695547, India.

∗ Corresponding
Abstract. Protostellar jets are
one of author.
the E-mail:primary
signposts of star formation. A handful of protostellar
sreelekshmimohan94@gmail.com
objects exhibit radio emission from ionized jets, of which a few display negative spectral indices, indicating
MS received 19 October 2022; accepted 7 March 2023
the presence of synchrotron emission. In this study, we characterize the radio spectra of HH80-81 jet with the
Abstract. Protostellar jets are one of the primary signposts of star formation. A handful of protostellar
help of a numerical model thatweexhibit
haveradio
developed
into
account
objects
emission from earlier,ionized jets,whichof which atakes
few display
negative
spectral bothindices, thermal
indicating free–free
the presence ofmechanisms.
synchrotron emission.
In thisstudy, we characterize
the radio spectra
HH80-81
jet with theand non-thermal synchrotron emission
Formodeling
the HH80-81
jet,of we
considerjet emission
help of a numerical model that we have developed earlier, which takes into account both thermal free–freetowards the central region closeandtonon-thermal
the driving
sourcealongwith two
Herbig-Haro
HH80
and HH81. Wesynchrotron
emissionmechanisms.
For modelingthe HH80-81 objects,
jet, we consider
jet emission
towards the central region close to the driving source along with two Herbig-Haro objects, HH80 and HH81. We
have obtained the best-fit parameters
for each of these sources by fitting the model to radio observational data
have obtained the best-fit parameters for each of these sources by fitting the model to radio observational data
corresponding
to twofrequency
windows
takenepochs.
across two epochs.
Considering an
numbernumber
density in density incorresponding to two frequency
windows
taken
acrosstwo
Considering
anelectron
electron
the range of 103 –105 cm−3 , we obtained the thickness of the jet edges and fraction of relativistic electrons that3
5
−3
obtained
the thickness
the jetedges
of relativistic
electrons thatthe range of 10 –10 cm , wecontribute◦ –0.1◦ and−7 –10−4 , respectively.
and 10fraction
For the best-fit
to non-thermal
emission in of
the rangeof 0.01◦◦−7−4
parameterinsets,thethe model
spectralin the range− 0.15 to+0.11 within
the observed frequency
andof 10–10, respectively.
For the best-fit
contribute to non-thermal emission
range
of indices0.01 lie–0.1
windows.
parameter sets, the model spectral indices lie in the range of − 0.15 to +0.11 within the observed frequency
Keywords. Radiation mechanisms: non-thermal—methods: numerical—stars: formation—stars: jets.
windows.

1. Introduction

Jets are considered to be closely related to the structure of the magnetic field within the protostellar system.
Keywords. Radiation
numerical—stars:
formation—stars:
Jetsmechanisms:
are launched alongnon-thermal—methods:
the axis of a rotating system Uponlaunch, the jet collimationis achieved by limiting jets.
as the outcome of accretion of materials from the sur- the pressure of toroidal component of helical magnetic
rounding interstellar medium (ISM). Accretion is aided fields (Livio 1997; Meier et al. 2001), which has been
1. Introduction
Jets are confirmed
considered
to hydromagnetic
be closelyand
relatedto the strucby jets, by acquiring the excess angular momentum
by various
magnetohy(Blandford & Payne 1982; Pudritz & Norman
1983)
drodynamic models
Ustyugova
ture ofthe magnetic
field(Lovelace
withinet al.
the1987;
protostellar
system.
and carrying it away. These jets could range from ultra- et al. 1995; Cerqueira & de Gouveia Dal Pino 2001;
Jets are launched along the axisrelativistic/relativisticof a rotatingjetssystem
launch,collimationis achievedin high energy Upon
astrophysical
Zannitheet al.jet
2004;
Bellan et al. 2005).
Theories pre-by limiting
phenomena (Mirabel
Rodríguez
Blandford
et dictof
similarframeworks
for the jet magnetic
fields, magnetic
as the outcome of accretion of materials
from&thesur-1999;thepressure
toroidalcomponentof helicalal. 2019) to non-relativistic jets in protostars (Reipurth regardless of them being protostellar or AGN origin
et al. 2004;
Lee et al. 2007)
and brown dwarfs(Whelan(Koenigl
1986;Meier
Livio 2000).
andwhichstrength has beenrounding interstellar medium (ISM).
Accretionis aided
fields(Livio1997;
et Theal.direction2001),
et al. 2009; Palau et al. 2014). Observational as well of the magnetic field can be determined with the knowlby jets, by acquiring the excessas modelingangularmomentumconfirmed
by ofvarioushydromagnetic
and magnetohystudies
have shown that protostellar
jets edge
synchrotron
emission parameters (Carrascocan either
or hamper
star-formation
activity in González
et al. 2010).
Low-noise sensitive(Blandford & Payne 1982; Pudritz& promote
Norman1983)
drodynamic
models(Lovelaceet al.observations
1987; Ustyugova
their immediate neighborhood (Li & Nakamura 2006; towards a massive protostellar jet had revealed theand carrying it away. These jets could
range
from
ultraet al.
1995;
Cerqueirade Gouveia
Dalcon-Pino 2001;
Nakamura& Li 2007;
Shimajiri
et al. 2008)
and alsopresenceof linearly &polarized
emission, which[ChatGPT]

HH80-81

⾒

-0.15

+0.11

⾒

HERBIG-HARO FLOWS AND YOUNG STARS IN THE DOBASHI 5006 DARK
CLOUD
1
1
2
1

T. A. Movsessian, T. Yu. Magakian, A. S. Rastorguev, and H. R. Andreasyan
T. A. Movsessian,1 T. Yu. Magakian,1 A. S. Rastorguev,2 and H. R. Andreasyan1

Two new Herbig-Haro flows were found in a study of the isolated Dobashi 5006 dark cloud (l = 216o.7,
Two new Herbig-Haro flows were found in a study of the isolated Dobashi 5006 dark cloud (l = 216o.7,

b = –13o.9): one certain(HH 1179) and one presumable, associated with the infrared sources 2MASSb = –13 .9): one certain (HH 1179) and one presumable, associated with the infrared sources 2MASSo06082284-0936139
and 2MASS 06081525-0933490,correspondingly.
correspondingly. Judging fromtheir spectral
06082284-0936139 and
2MASS 06081525-0933490,
Judgingfrom their spectralenergy distributions, these sources may be Class 1 objects with luminosities of order 23 L! and 3.6 L! ,energy distributions, thesesourcesmaybetheClass
objectsluminosities
order
23 L! and 3.6 L! ,respectively.
They arepart ofpoor star1cluster
MWSCwith
0739, studyof which based ofon datafrom theDR3 survey has made it possible to detect 17 stars which are probably members of it. A list of them
respectively. They areGaia
partof the poor star cluster MWSC 0739, study of which based on data from theand their main parameters is given. The distance of the cluster is estimated to be 820 pc and the color
excess onitthe
path to the clusteris E(BP17
mag. All oftheseprobably
stars are PMS-objects
and most- RP)stars| 1.05 which
Gaia DR3 survey has madepossibleto detectaremembersof it. A list of themof them are optically variable. It is concluded that the newly discovered compact star-formation zone inand their main parameters
is given.
ofthanthecluster
is estimatedto be 820
the Dobashi
5006 cloudThe
has andistanceage of no more
a few
million years
and this process continues
up to pc and the color
the present
time.isexcess on the path to thecluster
E(BP - RP) | 1.05 mag. All of these stars are PMS-objects and most
Keywords: Herbig-Haro objects: young stars: Dobashi 5006

of them are optically variable. It is concluded that the newly discovered compact star-formation zone in
the Dobashi 5006 cloud has an age of no more than a few million years and this process continues up to
1. Introduction
the present time.
One of the basic signs of an active star-formation process in dark clouds is the presence of Herbig-Haro objects.
Keywords: Herbig-Haro
objects: young stars: Dobashi 5006
[ChatGPT]On the other hand, the presence of infrared (IR) sources with a continual spectrum typical for young stellar objects,
Dobashi 5006
2

1

1. Introduction

820

17

MWSC 0739

V. A. Ambasrtsumyan Byurakan Astrophysical Observatory, National Academy of Sciences of the Republic of Armenia; e-mail:tigmag@sci.am
2
Physics Faculty, Lomonosov Moscow State University, Moscow, Russia

submitted
January 15, 2023.process
Translated in
fromdark
Astrofizika,Vol. 66,
pp. 61-74 (February
One of the basic signs Originalof an article
activestar-formation
cloudsis No.
the1,presenceof Herbig-Haro objects.