Star Formation NewsletterNo. 362 31-46
高橋実道（鹿児島大学/NAOJ）

31
32
33
34
35
36
37

system,theinagreement
RAMSES
PLUTO
regardingmanyterrestrialof the collapse
properties
and fragmentation
formation
progress. between
While there
is nowandevidence
that
Earth-sizedplanets
orbit a significant
fraction of
discovered
eight
Scutifromcandidates.
NoneofMaxwellthese werepreviously
known.
Furthermore,
weRMS
detected
17 witheclipsing
spectraldata
products
the
James
Clerk
Telescopearchive,centeredonthetwo
objects
7’x7’
processisgood.
Fragmentation
occurringintheinnermostregionandnumerical
choices
(use
of
sink
particles,
grid)
StructureandKinematics
of
Sh2-138–A
distant
hub-filament
systemintheoutersolar-typestars,
theanticipateddusty
debrissignatureof
theirformationisrarelydetected.
Here
we
discuss
severalbinaries
whereeach,
two werepreviously
known.
Based onThethe 13CO(3-2)
proper motions
providedbythe
the region
Gaia EDR3
catalogue,
we
field
of
view
were
utilisedforthepurpose.
channel
map
of
shows
the
molecular
haveaincrucial
impactwhen ideas
similarbut smooth
initialconditions
areimply
employed- moremechanisms
crucial thancapable
the code’s
choice the
Galactic
plane
ways
which
our
current
about
terrestrial
planetformationtransportoferasing
calculated
the cluster
membershipprobabilities
for 91fromvariablestars.
Forstar,
61 variables,
a probability
higher
than
80%
cloud
to
have
filamentary
extensions
directedaway
themassive
which
also
seems
to
be
at
the
edge
of
a
on
the
system’soutcome,multipleorcentrally-condensed.
Kshitiz
Mallick,
LokeshDewangan,
Devendra
Ojha,
Tapas
Baug,
Igor
Zinchenko
F
We
presentamolecular
anticipateddebrissignature.
A tenuousgas disk protostar:may
be25regenerated
viaa"takeout"theliberationofplanetary
Diskfragmentation
arounda massive
a comparisonof (i.e.,twothree-dimensional
wasdetermined,
which
makes
them
clustermembers.
Only
variableswithprobability
less
than
20%
were
regardedcavitylike ofstructure.
Multiplemolecular
cloud
protrusions
into
thiscomets
cavitystructure
hostterrestrial
local its
peaks
of emission.
line
study
the
Sh2-138(IRAS
22308+5812)
hub-filament
system
with
an
aim
to
investigate
structure
and atatmospheresingiant
impacts)or"delivery"(i.e.,
byasteroids
and
flung
into
the
planetregion)codes
tobe integrated
non-members.
Theemissionmapofthe
regionconstructed
from
only
those
emissionclumpsdetected
above
5
level
in
kinematics.
ArchivalCOmolecular
line
data
from
the
Canadian
Galactic
Plane
Survey(CO(J=1-0))
for
the
wider
a levelsuﬃcient
to removethe warmdebris.
The
powerfulstellarwind NGCfroma youngstar can F
alsoact, its delivered
Raphaël
Mignon-Risse,
André
Oliva,
Matthias
González,
Rolf
Kuiper,BenoîtCommerçon(Abridged)
Most
A
CCD
Searchfor
Variable
Stars
in
the
Open
Cluster6611
theposition-position-velocity
space
aﬃrms
the
same.
MSX
sourceswerefound distributedalong
the cavityplanets
boundary
region(50arcminx50arcmin)
and
the
James
Clerk
Maxwell
Telescope(CO(3-2),
13CO(3-2),
and
C18O(3-2))
for themay
wind
momentumproducing
a
drag
that
removeswarm
debris.
If
suchprocesses
areeﬃcient,
terrestrial
massivestars
arelocatedinmultiplesystems.
The
modelingofdisk
fragmentation,apossiblemechanism
leadingtoG.
Michalska,Z.
Kołaczkowski,
R.
Leiton,O.
Szewczyk,
K.
Kinemuchi,
V.,
M.
KalariF
We
present
theresultswhere
thegas hastheandbeenMassive
compressed.
Spectralextraction
atthe
these
positionsyieldedhighMachnumbers
and inlow
centralportion(5arcminx5arcmin)
have
been
utilised.
AnalysisoftheCO(1-0)spectrafortheextendedregionSpiralStructureStarformationin
Hub-Filament-System
G326.27-0.49
assembleinconspicuously,
withlittlepublicity
andhooplaaccompanying
theirbirth.
Alternatively,therarityofwarm
stellarmultiplicity,reliesonparallel3D
simulation
codes
whose
agreement
remainstobeevaluated.
Using
the
Cartesian
of
the
U
BV
I
variability
survey
in
the
young
open
cluster
NGC
6611
based
on
observations
obtainedduring34
nightsC
ratiosof thermal
to non-thermalpressure,suggestingaWyrowski,
dominanceof supersonicandnon-thermal
motion inthecloud.
conjunction
with
the
hub
and
filament
identification
using
columndensity
map
and
the
getsf
tool,
respectively,
reveals
Bhaswati
Mookerjea,
V.
S.
Veena,
Rolf
Guesten,F.
Akhil
LasradoF
Hub-filament
systems(HFSs)
areexcesses
may
imply
that
terrestrial
planets
typically
form
very
early,
emerging
fully
formedfromthenebular
phase
AMR
code
RAMSES,
wecomparedisk
fragmentationinacentrally-condensed
protostellar
system
to
the
study
of
Oliva
spanning
one
year.
In
total,
wefound
95
variablestars.
Most
of
these
stars
are
classified
asperiodicandirregular
Investigatingthemorphology
and
COfor
gas
kinematics
ofdisplaying
Sh2-112
regionacomplexstructurewiththespectralextraction
thecentralposition
multiplevelocity
components.
potentialsites
offormationofstarclusters
and
high
mass
stars.
To
understand
the
HFSs
and
torunsprovideobservational
without
undergoinglate-stage
giant
impacts.
Ineithercase,
theobservable
signpostsofterrestrial
planetformation&
Kuiper(2020)
performed
on
a
grid
in
spherical
coordinates
using
PLUTO.
Two
RAMSESareconsideredandpre-mainsequence(PMS)
stars.
The
analysis
of
the
JHK
2MASS
photometryandfour-colour
IRAC
photometry
Kshitiz
Mallick,
Saurabh
Sharma,LokeshDewangan,
Ojha,
NeelamPanwar,
Tapas
Baug
F be
We
SDevendra
Based
on
the
Herschel70
micronwarm
dust
emission,
one
of
the
filaments
intheextendedregionwasinferredtoconstraints
oncurrent
theoriesthat
attempttoexplainstar
formation
globally,wereport
a
study
of
the
regionassociatedappearmore
challenging
todetectthan
previously
assumed.
Wesinkdiscuss
observational
tests
of transition
these ideas.
givequalitatively
distinct
pictures.
When
allowing
forunlimitedparticlecreation,
gasan3-2
fragmentation
leads
to
a
Takeout
andDelivery:ErasingtheDusty
SignatureofLate-stage
Terrestrial
Planetrevealed
165
Class
II
young
stellarsources,
20
of
which
are
irregular
variables
and
one
is
eclipsingbinary.
These
present
a
study
of
the
molecular
cloudin
Sh2-112
massivestarforming
region
using
the
of
CO
isoassociatedwithactivestar
formation,
and
is
host
to
a
Bolocam
1.1
mm
clump
of
1606
Msun.
Integrated
intensitymap
with
G326.27-0.49
using
infrared
data
of
dust
continuum
andnewly
obtained
observationsonmolecular
tracersusing
multiplestellarsystemwhose
multiplicity
isaﬀected
by
the
grid
when
triggeringfragmentation
andbynumericallyFormation
classifications,complemented
by JHK
UKIDSS
photometry
and
riH↵
VPHAS
photometry,used
to reveals
identify
topologues
- CO,
13CO,
and
C18O;
supplemented
in partatby
CGPS
HI lineemissionand structures
MSXweredata.
Sh2-112isanof
13CO(3-2)
emission,constructedfromclumpsdetectedabove
5sigmainposition-position-velocity
space,the
APEX
telescope.
We
use
the
spectroscopic
observations
toidentify
velocity-coherent(filaments
andassisted
On
the
other
hand,
using
aformation
unique,central,fixed
sink3216,
particle,aaddition
centrally-condensed
systemforms,
Joan
R.mergers.
Najita,Scott
J.
KenyonF
The
ofstarplanets
like
Earth
isInexpected
toRed
concludewitha sources
seriesof24
candidates
forclassical
T
Tauri
stars
and
30
weak-linedT
Tauristars.
tothe
PMS
variables,
we
optically
visibleregionpowered
by
an
O8V
type
massive
BD
+45
and
hosts
two
MSX
SurveyEarly
waterdeliverytoterrestrial
planetregions
duringthestagesofJupiter’s
formation
three
filamentary
structures(labelled
W-f,
SW-f,
and
SE-f)
in
the
centralportion.
Velocity
gradients
observedinclumps)
and
study
their
properties
ataresolution
of
0.4
pc.
The
regioncontains
two
mainvelocity
components:
firstsimilartothatreportedin
PLUTO.
The
RAMSES-PLUTO
comparison
isperformedwiththelatter:agreement
late-stage giant
impacts
that generateNone
warmof-dusty
debris,the region
most anticipatedvisible object,signpostof terrestrial
planetdiscovered
eight
Scuti
candidates.
these
were
previously
known.
Furthermore,
wedetected17
eclipsingG083.7962+03.3058
andG083.7071+03.2817
classified
as
HII
and
young
stellarrespectively.
Reducedandmigration
in
the
Grand
Tack
model
13CO(3-2)
position-velocity
slicespoint
tolongitudinal
gas
flow
along
the
filaments
into
thecentralregion.
Filaments
component
shows
four
filaments
between
-63
and
-55
km/s
formingaspiralstructure
converging
in
a
hub,
the
secondof
between
the
two
codes
is
found
regardingthefirstrotationally-supported
disk
formation,
thepresenceofanaccretionformation
inprogress.
While
there
is
now
evidence
that
Earth-sized
terrestrial
planetsorbitasignificant
fractionbinaries
where
two
were
previously
known.
Basedonthepropermotions
provided
by
the
Gaia
EDR3
catalogue,
wespectraldata
products
from
the
James
Clerk
Maxwell
Telescopearchive,centered
on
the
two
RMS
objectswith
7’x7’
Masahiro
Ogihara,Hidenori
Genda,
Yasuhito
SekineF
The
formationandsubsequentmigrationofgas
giants
could
W-f,
SW-f,
and
SE-f
were
calculatedtohave
observed
line
masses
of
32,
33.5,
and
50
Msun/pc,
respectively.
Thefilamentarycomponent
at -72 km/s
harborsaGaseous
massive fragments
youngstellarobjectpossiblyinteracts
with
the
hub.
The
shock
onto
it,
the
first
fragmentation
phase.
form
and
their
properties
areinagreement
betweensolar-typestars,
theanticipateddusty
debrissignatureof
theirformationisrarelydetected.
Here
we
discuss
severalcalculatedtheclusterprobabilities
for91
variablestars.
For
61Msun),variables,
a luminosities
probability
higher
than
80%
field
ofwas
view
each,
were
utilisedforpurpose.
The
13CO(3-2)
channelmapofhavetheregionshows
thetomolecularsignificantly
aﬀect
the
material
mixinginthe region
Solar
System.
In
thisstudy,
we useN-bodysimulations
investigate
cloud
found
tothe
bemembership
dominatedby thesupersonicandnon-thermal
motions,
with
high
Mach
numbers
(>3)
and
low
clumpsharbouring
three
main
YSOs
are
massive(187-535
consistent
with
the
two
codes.
As
acurrentminor
diﬀerence,fragments
dynamics
causesthedisk
structure
to be
sub-Keplerian
RAMSES
ways
in
which
our
ideas
about
terrestrial
planetformation
imply
transportmechanisms
capableofinerasing
thewasdetermined,
which
makes
them
clustermembers.
Only
25
variableswithaprobability
less
than
20%
were
regarded
6
3
cloud
to
have
filamentary
extensions
directed
away
from
the
massive
star,
which
also
seems
to
be
at
the
edge
of
a
thermalto non-thermalpressure
ratio(0.01-0.1).
how muchwater
iscentraltransported
into
the
regionof theterrestrial
planet formation
duringthe growth and clumps
migration
B-typestars,
have
densities
of
10
cm
and
drive
large
outflows.
Majorityofthevelocity-coherent
whereasit isstructure.
found tobeMultiple
Keplerianand reaches
quiescence
PLUTO.
We
attribute
thisdiscrepancy
to theof
centralstar
anticipateddebrissignature.
A moleculartenuousgas
disk
may be inregenerated
via"takeout"(i.e.,
thelocalliberation
planetary
tobenon-members.
cavitylike
cloud
protrusions
into
this
cavitystructure
host
peaks
of
emission.
phasesofJupiter
in
the
Grand
Tack
model.
We
found
that
Jupiter’s
growthwasaccompaniedbysignificant
mass
in
the
regionshow
virialparameters
between2-7,
which
considering
thedetectionofprotostars
impliescollapse
to
be
being
twice less
inmap
RAMSES
becauseoftheby
diﬀerent
stellarsubgridmodels.
In a centrally-condensed
atmospheresin massive
giant impacts)
orthe"delivery"(i.e.,
asteroids
andaccretion
cometsemission
flung
into
the terrestrial
planetregion)at
4The
integrated
emissionofregionconstructed
from
only
those
clumpsdetected
above
5
level
in
transport,
and
that
a
substantial
amountofwater(about10
times
Earth’s
ocean
mass
for
the
initialplanetesimal
gradual.
We
concludethattheregionconsistsofa
networkoffilaments
throughwhich
massaccretes(10
Msun/yr)system,the agreement
betweenRAMSES
andPLUTO
regardingof
theacollapse
properties
andfragmentationa levelsuﬃcient
to removethewarm
debris.
The
powerfulstellarmany
wind
from
young star
can also
act,
its boundary
deliveredtheposition-position-velocity
space
aﬃrms
the
same.
MSX
sources
were
found
distributed
along
the
cavitydistribution
based
on
the
minimum-masssolar
nebula)wastransported
intotheterrestrial
planetregion.
The
total
onto
the
hub.
The
hub
and
some
of
the
ends
of
filaments
appeartobeundergoingcollapse
to
form
new
stars.
This
SpiralStructureandMassiveStar
formation
inthe
Hub-Filament-System
G326.27-0.49
process
is good.
Fragmentation
occurringin the innermost
regionand positions
numericalyielded
choices(useMachof sink
particles,
grid)wind momentum
producinga dragthat removes
warm
debris.
Ifthesesuchprocesses
areeﬃcient,
terrestrial
planets
may
where
the
gas
has
the
been
compressed.
SpectralextractionathighnumbersandlowamountdeliveredincreasedfurtherduringJupiter’s
migration
phase(totaling
about
10-40
times
Earth’soceanmass),
study
identifies
atargetregionfor
futurehighresolution
observations
that
could
probe
the
link
between
the
core
and
Bhaswati
Mookerjea,
V.
S.
Veena,
Rolf
Guesten,F.
Wyrowski,
Akhil
LasradoF
Hub-filament
systems(HFSs)
arehaveacrucialimpactwhen
similarbutsmoothinitialconditionsareemployedmorecrucialthan
thecode’schoiceassembleinconspicuously,
withlittlepublicity
andhooplaaccompanying
theirbirth.
Alternatively,
rarityofwarm
ratiosofwas
thermalto non-thermalpressure, suggesting
a dominanceof supersonicand non-thermal
motion inthenotcloud.
filament
evolution.
which
less
dependent
onsimulation
parameters.
In
addition,atthesestages,terrestrial
planetswere
fully
potentialsites
offormationofstarclusters
and
high
mass
stars.
To
understand
the
HFSs
and
to
provideobservationalon
the system’s
outcome,multiple orplanets
centrally-condensed.
excesses
may imply
that terrestrial
typically form
11 very early, emerging fully formed from the nebular phasegrown. Therefore,
water
suppliedduringthesestagescouldinteractwithmetalliciron
duringthe core
formation
constraints
on current
theoriesthat
attempt
to explainstar
formation
globally,wereportaofstudyof the region
associatedwithout
undergoinglate-stage
giant
impacts.
Inearlyeithercase,
the observable
signposts
terrestrial
planetformationof 21-0.4(r)0.4(o)0.1(t)0.20.1(p)-0.4of(l)0.3the(a)0.1Dusty(n)-0.4and(e)-0.3(t)0.2(s)-421.3(a)0.1(n)tests-0.4on
(d)
-0.4
/aor
gro(i)
0.3using(n)-0.4ince(g)-410.9hydrogen
Egarthin water mowith
G326.27-0.49
using
infrareddata
dust
continuum
newly
obtained
observations
molecular
tracers
Takeout
andDelivery:ErasingSignatureof Late-stage
Terrestrial
Planetappearmore
challenging
to(o)detectthan
previously
assumed.
We
discuss
observationalof
these
ideas.
A
CCD
Stars in observations
the Open toCluster
NGC 6611 structures (filaments andthe
APEX Searchtelescope.for
WeVariable
use the spectroscopic
identify velocity-coherent
Formation
G.
Michalska,
Z. Scott
Kołaczkowski,
R.
Leiton,O. Szewczyk,
K.
V.,
M.
F
We present
resultsclumps)study
their J.
properties
atF
a The
resolutionof 0.4ofpc.
TheKinemuchi,
regioncontains
twoKalarimain
components:
first
Joan
R.and
Najita,Kenyonformationplanets
like Earthis expected
to velocity
concludewith thea series
of
12
Early
water
deliverytogenerateterrestrial
planetregions
duringstagesofJupiter’s
formationofthe U BV
IC variability
surveyin the young
open
cluster
NGC
6611
based
on
observations
obtainedduring34secondnightscomponentshowsfour filaments
between-63 and-55
km/s
forminga anticipatedspiralthe
structure
converging
in
hub,
the
late-stage
giant
impacts
that
warm
dusty
debris,the most
visiblesignpostof aterrestrial
planetand migration
in total,the
Tackspanning
one
year. Inwe
found
95 variable
stars.
Mostof thesestars
classified
asaperiodic
andfraction
irregular
filamentaryat-72Grandkm/s
harborsa modelmassiveyoung
stellarobjectandarepossiblyinteractswith thehub.
Theformation
incomponent
progress.
While
there
is
now
evidence
that
Earth-sized
terrestrial
planetsorbit
significantofMasahiro
Ogihara,Hidenori
Genda,
Yasuhito
SekineF
The
formationandsubsequentmigrationof gasgiantscould
pre-mainsequencestars.
The
analysisofregion
the JHK
photometryandfour-colour
photometry
S 2MASSclumpsharbouring
the
three
main
YSOs
in theare(187-535
have
luminosities
consistentwithsolar-typestars, the(PMS)
anticipateddusty
debrissignatureof massive
theirformationis Msun),rarelydetected.
Here IRAC
we
discuss
severalsignificantly
theyoung
material
mixingin6theIn thisstudy,
weuse
N-bodysimulations
to erasing
investigate
revealed
165 aﬀect
ClassII
stellarsources,
20 Solarof3 planet
which
are large
irregular
variables
andmechanisms
one
eclipsing
These
B-typehave
centraldensitiesof terrestrial
10cm
andSystem.
drive
outflows.
Majority
of is
thean
velocity-coherent
clumpsways
instars,which
our current
ideas
about
formation
imply
transport
capable binary.
of
the
how
water
isvirialtransported
into
theUKIDSS
regionthe beterrestrial
formation
duringthe liberation
growthandclassifications,complemented
bytenuous
JHK
andplanet
riH↵
VPHAS
photometry,
were
used
identify
inthemuchregionshow
parameters
between2-7,ofphotometry
whichconsidering
theviadetectionofprotostars
impliescollapse
to beanticipateddebrissignature.
A
gas
disk
may
regenerated"takeout"(i.e., theoftomigration
planetary4phasesof Jupiterthe Grand
Tackstars
model.
found that T
Jupiter’s
growthInwas
accompanied
significant
mass
24
candidates
for inclassical
T Tauriand We30 weak-lined
Tauri stars.
additionto the by
PMS
variables,
we37

Early water delivery to terrestrial planet regions during the stages of Jupiter’s formationand migration in the Grand Tack model

Masahiro Ogihara, Hidenori Genda, Yasuhito Sekine F The formation and subsequent migration of gas giants could

significantly aﬀect the material mixing in the Solar System. In this study, we use N-body simulations to investigate
how much water is transported into the region of the terrestrial planet formation during the growth and migration
phases of Jupiter in the Grand Tack model. We found that Jupiter’s growth was accompanied by significant masstransport, and that a substantial amount of water (about 10 times Earth’s ocean mass for the initial planetesimal
distribution based on the minimum-mass solar nebula) was transported into the terrestrial planet region. The total
amount delivered increased further during Jupiter’s migration phase (totaling about 10-40 times Earth’s ocean mass),
which was less dependent on simulation parameters. In addition, at these stages, terrestrial planets were not fullygrown. Therefore, water supplied during these early stages could interact with metallic iron during the core formationof protoplanets and/or growing Earth. Since hydrogen in water molecules can dissolve into their cores, this could
explain the density deficit observed in the current Earth core. Notably, Jupiter could play an important role as a”barrier” in explaining the dichotomy of the isotopic compositions between noncarbonaceous (NC) and carbonaceous(CC) meteorites. This study’s results show that Jupiter’s growth necessitates some mixing of NC and CC materials.

ALMA Band 6 high-resolution observations of the transitional disk around SY Cha

Ryuta Orihara, Munetake Momose, Takayuki Muto, Jun Hashimoto, Hauyu Baobab Liu, Takashi Tsukagoshi, Tomoyuki Kudo, Sanemichi Takahashi, Yi Yang, Yasuhiro Hasegawa, Ruobing Dong, Mihoko Konishi,
Eiji Akiyama F In this study, we reported the results of high-resolution (0.14 arcsec) Atacama Large Millime-

ter/submillimeter Array (ALMA) observations of the 225 GHz dust continuum and CO molecular emission lines from13⌃g,vis = 1320

ort.
10 9 M yr 1
10 4
as calculated
accordingto the enve⇣ r ⌘ 3/8
Water
delivery
2
⇥
g
cm
, (1)
tz contraction using Eqs. (41)–(42)1 au !
地球の海の起源、地球コアの密度欠損の原因（コアへの水の供給）
2021) (see also Hori & Ikoma 2010),⇣ ↵ ⌘ 1Ṁg
海の起源は惑星形成後の質量降着だと思われてきたが、コアへ水を供給するには惑星形成中に水が必要。
the planet
using Eqs. (15)–(16) of⌃g,irr = 2500
9 M yr 1
4101020) (see also Tanigawa & Tanaka⇣ r ⌘ 15/14
Tackモデル(木星が3.5auで形成した後1.5
auまで落下したのち今の軌道
5.2 au に移動する)
3
ccretionGrandusing Eq.
(19) of Ogihara &
2
⇥
g
cm
, (2)
stops gasaccretionwhenitreachesで木星の成長期、移動期に水がどの程度地球型惑星に供給されるかを調べる。
1 au
For
the gas disk model, although disk models thatur fiducial
Jupitercore gained attention
account setup,for diskthewinds
have recently
9
where
we
assumeṀ=10exp[(tg
ss in N体計算
about
1
Myr.
When
Jupiter(Suzuki et al. 2016; Ogihara et al. 2018b), we used a sim1
1Myr)/(0.5
Myr)]
M
yr
for the fiducial case andple two-component
power-law (e.g.,
disk model (e.g., Bitsche limited
by
the
disk
accretion
３成分
4
↵
=
10
. Jupiter opens a density gap in its vicinity,
et
al.
2015;
Liu
et
al.
2019).
In
thismodel,
thediskis8) and becomes near linear growth.
dividedinto the inner region, wherea=3.5
the temperatureis also considered in this study by using a かけてMjまで成長
which
was
model
木星：初期質量10Me,
au,
先行研究の形成モデルを使って1Myrt of Jupiter’s growth rate, we also
determined by viscous heating (vis), and theinouterre- the depth and width of the gap is determined
whichwheregion,
Jupitergrows
quickly->a=
1.5 inauabout-> 5.2
au と移動(t=1.5Myr)
where
stellarirradiation(irr)
determines
the diskby
giant
planet
mass
and
disk
properties(e.g.,
viscosity)
Youdin2014)
bychangingthedisktemperature. Each region has a dominant heating mechplanetary
embryos：0.05Me
40個(Kanagawaet al. 2017; Shibata & Ikoma 2019).
anism and switches from the viscous regime to the irragas drag damps
the eccentricity
andregimeinatthe
a specificradius(see Eq. (14)As
ofaerodynamicalLiuplanetesimal:
1.3-6auに分布、0.005Me
1106個or
0.0025Me
2212個、MMSNの面密度分布
ation,diation
migration
Grand
Tack
et al. (2019) for location). The gas surface inclination
density in of planetesimals, we calculated the drag force
d basedon Walsh et al. (2011)
each region is expressed byby the following
formula (Adachi et al.
1976).
activeガスによる微惑星のe,iのdumping015).ガス(passive
Jupiter movedor
inwardon )a!1/2⇣ ↵ ⌘ 3/4
Ṁ
2
and moved
outwardafter
reachinggC⇡R⇢g vrelD⌃g,vis = 1320
9 M yr 1
4
Faero =
vrel ,(3)
10
10
he outward migration, as stated in
2M
⇣
⌘
3/8
r
and Carter et al. (2015), the migra2
⇥
g cm
, (1)
where
⇢g is the gas density, vrel is the relative velocity
1
aud down by considering exponential !
で力を計算
⇣
⌘
betweentheplanetesimal and gas, and R is the radius
1Ṁ↵g
ed at its current
orbit⌃g,irr =2500 (a =9 5.2 au)1
4 planetesimals and is varied between 5–500 km to de10 M yr
10 of
⇣ r ⌘ 15/14 termine the e↵ect of gas damping strength. The drag⇥g coefficient
cm 2 , (2) C is calculated according to the Mach numD
1 au

木星成長期

木星移動期s Figure 1 but for di↵erent parameters. (a) The planetesimal is 5 km in size and the eccentricity damping
a<3.5
auに供給された水は内側への移動で
planetesimal is 500 km in size and the eccentricity damping is weak. (c) Jupiter is in rapid growth withon a timescale
about
0.1 Myr. The planetesimal is 50 km in size.
<1.5 ofauに掃き集められる

Figure 5. Same as Figure 2, but the total amount of water
最終的に a<2 auに>10Meoの水が供給
delivered into the region of a < 2 au during the growth andmigration phase of Jupiter.

ots of the system during the migration phase. Jupiter moves inward and outward according to the Grandur fiducial setting with planetesimal of 50 km in size. (b) The planetesimal is 5 km in size.

where the plus/minus sig
in fitting. This equation
well for di↵erent sizes an
cept for R = 5 km. On
noted that this fitting fo
in Appendix B, where th
configuration of giant pla
By combining Eq. (4)materials, the transport f
can be calculated. By as
tribution of water,⌃d,w = 10⌘w

where ⌘w is the initial wa
etesimal described in Sec
livery can be calculated
yields 31 MEO and is con
ter delivery shown in Fi
in Figure 6 are obtainedwater distribution. The
be used to estimate the
distribution. Although w
mary focus of this papermaterials delivered into

the fiducial case, the final transport between the cases
地球の形成期に十分な水を供給できるので、コア密度欠損を説明できる。

y between the cases R = 50 km andot di↵er significantly.
e results when Jupiter was growing
growth phase was considered. The
same as when Jupiter grows moreof R = 50 km and 500 km did not di↵er. In addition,
the final water transport did not depend on Jupiter’s
growth timescale. Therefore, the amount of water delivered did not depend much on the simulation parametersagreement with previous results and an improved quantification of uncertainties in cloud properties.

42 The ALMA view of MP Mus (PDS 66): a protoplanetary disk with no visible gaps
down to 4 au scales

Á. Ribas, E. Macías, P. Weber, S. Pérez, N. Cuello, R. Dong, A. Aguayo, C. Cáceres, J. Carpenter, W. R. F.
Dent, I. de Gregorio-Monsalvo, G. Duchêne, C. C. Espaillat, P. Riviere-Marichalar, M. Villenave F We present

ALMA multiwavelength observations of the protoplanetary disk around the nearby (d⇠100 pc) young solar analog MP
Mus (PDS 66). These observations at 0.89 mm, 1.3 mm, and 2.2 mm have angular resolutions of ⇠ 1", 0.05", and 0.25",
respectively, and probe the dust and gas in the system with unprecedented detail and sensitivity. The disk appears
smooth down to the 4 au resolution of the 1.3 mm observations, in contrast with most disks observed at comparable
spatial scales. The dust disk has a radius of 60±5 au, a dust mass of 0.14+0.11
0.06 MJup , and a mm spectral index < 2in the inner 30 au, suggesting optically thick emission from grains with high albedo in this region. Several molecular
gas lines are also detected extending up to 130±15 au, similar to small grains traced by scattered light observations.
Comparing the fluxes of diﬀerent CO isotopologues with previous models yields a gas mass of 0.1 1MJup , implying
a gas to dust ratio of 1-10. We also measure a dynamical stellar mass of Mdyn =1.30±0.08 M and derive an age of
7-10 Myr for the system. The survival of large grains in an evolved disk without gaps/rings is surprising, and it ispossible that existing substructures remain undetected due to optically thick emission at 1.3 mm. Alternatively, small
structures may still remain unresolved with the current observations. Based on simple scaling relations for gap-opening
planets and gap widths, this lack of substructures places upper limits to the masses of planets in the disk as low as 2
M -0.06 MJup at r > 40 au. The lack of mm emission at radii r > 60 au also suggests that the gap in scattered lightbetween 30-80 au is likely not a gap in the disk density, but a shadow cast by a puﬀed-up inner disk.

Empirical constraints on turbulence in proto-planetary discs

Giovanni P. Rosotti F Proto-planetary discs, the birth environment of planets, are an example of a structure com-monly found in astrophysics, accretion discs. Identifying the mechanism responsible for accretion is a long-standing
problem, dating back several decades. The common picture is that accretion is a consequence of turbulence, withseveral instabilities proposed for its origin. While traditionally this field used to be a purely theoretical endeavour,the landscape is now changing thanks mainly to new observational facilities such as the ALMA radio interferometer.
Thanks to large improvements in spatial and spectral resolution and sensitivity (which have enabled the study of discsubstructure, kinematics and surveys of large disc populations), multiple techniques have been devised to observationally measure the amount of turbulence in discs. This review summarises these techniques, ranging from attempts at

where uncertainty
Mdust is disk
dust
mass,
F
is
the
flux
at
the
observed⌫(10 % for Band 7 and 5 % for Bands 6 and 4).
frequency ⌫, Tabled is thedistance tothe source,
⌫for
is MP
the dust
3. Summaryof results
derivedMus. opacity
解析結果まとめatthefrequency
⌫,
and
B
(T
⌫ dust ) is the blackbody emission at the
MP Mus (PDS66)
olved in both the 1.3 mm and 2.2 mm observations. We used corresponding frequency andParameter
dust temperature
Value T dust . Since wepertureto estimate continuum fluxes from these im- have observations at three di↵erent
TWphotometry
Hya に次いで近傍にある(97.9pc)、
can computeM⇤,dyn frequencies,
1.30 ±we
0.08M
ges, obtaining 370±40 mJy at 0.89 mm, 148±7 mJy at 1.3 mm, three dust mass values. We adopted
standard
for the opac1.2values± 0.1Lgas rich 円盤(r~130au)を持つ classical T Tauri star (1.3Msun, 7-10Myr) L⇤
nd 49±2 mJy at 2.2 mm (see Table 4). These uncertainties are ity and dust temperatures of Age
† =2.3 cm2 /g and T
230 GHz
7 - 10 Myr dust = 20 K
散乱光が60-80auで暗くなる
argelydominated by absolute calibration and not the noise in the (e.g., Andrews & Williams V2005),
and a 3.98
distance
d=98 pc± 0.04ofkm/s
LSR
mages.
The emission at 1.3 mm and 2.2 mm extends up to 60 au (Gaia Collaboration et al. 2022).
+0.11 at 0.89 mm
Fortheobservations「若い太陽系」として有効な研究対象
M
0.14
dust
0.06 MJup00
0.6 ), as determined from the 3-5 contours. To ease the com- and 2.2 mm, we computed thevalue using a⌫ Jup
Mgascorresponding
0.1-1M
arisonwith other studies,
we also list6theradii enclosing
68 % power-law dependence of the††
opacity
with60frequency,
i.e. ⌫ =ALMAでBand
7 (0.89mm),(1.3mm),4 (2.2mm)で観測
Rdust± 5 aund 90 % of the total flux in Table 5. Based on the most com- 230 GHz ⇥ (⌫/230 GHz) , where††isbetween
0.0-0.6
for
most
12
R
130
±
15
au
gas ( CO)(~1”,0.05”~4au,
0.25”)
act antenna configuration in each band (Table 1), the maximum protoplanetary disks (e.g., Tazzari
et al. 2021,
also
in agreement
i
32
±
1
dust
SPHEREのデータ解析も行う
ecoverable
scales are ⇠10.800 , 2.900 , and 8.300 at 2.2 mm, 1.3 mm with the range of 0.1-0.4 derived
for MP 10
Mus
in Sec. 4.2). We
PA
±
1
dust
nd 0.89 mm, respectively2 , which are significantly larger than bootstrapped the dust massesDoLP
and their uncertainties
by adopting
0.46 ± 0.08%
he observed disk size. Therefore, the observations are likely uncertainties of 5 K for T dust and
20 % for 98
AoLP
8 , and a uniform
230 ±
GHz
ダスト連続波ecovering
all the emission fromdisk. no.
We
A&Atheproofs: manuscript
ms also produced
distribution of values between 0 and 0.6. The derived disk dust
+0.1(†) Based on the
+0.07
+0.07
mages with a lower robust value of -0.5 to try to reveal masses are 0.16
Notes.
derivedluminosity
and theMIST
isochr
M
,
0.13
M
,
and
0.13
M
at
Jup
Jup
Jup
0.04 and model
0.04The observed contin
0.05 1.3 mm observations
Fig. 2. ALMA
00(††) of MP Mus.
2016;
Choi
et(theal. 2016).
The uncertainties
corresponmall substructures, reaching angular resolutions of 0.89⇥0.66 , 0.89 mm, the
リング、ギャップ、非軸対象構造は
1.3(Dotter
mm,
and
2.2
mm
reportedvaluescorrespond
frank radial profile (middle) are shown. The residuals (right) are displayed i
00
00
00
00
beam
size
of16
the%,
observations.
.06 ⇥0.04 , and 0.25 ⇥0.19 at 0.89 mm, 1.3 mm, and 2.2 mm to the medianandthe
観測されず and 84 % percentiles). These valcorresponding to ⇠75, 4, and 20 au at 98 pc). Interestingly, the ues are allTable
compatible
withencompassing
each other,
adopt
final
5. Disk radius
68 and% andwe90 %of theatotal
flux.dust major+0.11
mass value of
M
=
0.14
M
as
the
average
of
the
three
dust
Jup
0.06
solved in both the 1.3 mm and 2.2 mm observations. ↵=1.3
We u
See ALMA Technical Handbook
measurements.
observ
aperture photometrytoestimate
continuum
fluxesfromtheseComponent
R68 % (au) R90 % (au)inclinages,Continuum
obtaining(1.3370±40mJy30±5at 0.89 mm,
148±7 mJy at 1.3 m
mm)
45±5
ment
rticle number, page 4 of 20
and 49±2mJy (2.2
at 2.2mm (seeTable 4).
These uncertainties
Continuum
mm)
30±20
45±20
directlargelyGas
dominatedby absolutecalibrationand not the noisein(12 CO (2-1))
80±15
110±15decreaimages. The emission at 1.3 mm and 2.2 mm extends upslope
to 6(0.600 ), as determined from the 3-5 contours. To ease bumpthe c

eam size of the observations.

eralstar-forming
regions (e.g. Ricci
al. 2010b,a;k
calculates
super-resolution
radialetprofilesof Ribas et al. 2017; Tazzari et al. 2021). Using the derived con017;
Tazzari etazimuthalal. 2021).symmetry,
Using the aderived
con- tinuum fluxes, we computed three spectral indices in di↵ersks assuming
condition
Spectral
index
,hewe
computed
three
spectralindices indi↵er- ent wavelength ranges: ↵0.89 1.3 mm = 2.4 ± 0.3, ↵1.3 2.2 mm =case of MP Mus. We
tried di↵erent
combih↵ranges:↵0.89 1.3
0.3,
↵1.3
= mm
平均wsmooth’sandhyperparameters
and
found
2.12
± 0.11,↵0.89 2.2 mm = 2.25 ± 0.13 (including the abmm = 2.4 ± Fig.
2.2 mm3.
Radialprofilesofno
the 1.3
continuum
and COand(2-1) emissionof MP Mus. The
continuum
profile derived from the synthesizednd ↵β~0.1-0.4
=
2.25
±
0.13
(including
theab0.89 2.2 mm → mm size ダスト
ALMA image is shown as a red line, and the orange line corresponds to12

the resulting profile from frank (Jennings et al. 2020). The profile forthe 12 CO (2-1) line is also shown as a blue line. The 1- uncertainties
Article number,pageof (2-1)
20 are also plotted as red and blue shaded
動径分布
内側ほど小さい：光学的に厚い、大きいダストのドリフト
for the continuumand512 CO
areas. In all cases, we adopted a disk inclination and PA of 32 and 10 .
For comparison, the FWHM of the continuum and 12 CO (2-1) beams
β<0 :光学的に厚く アルベド大
ダスト質量は過小評価
are also shown
as solid horizontal red and blue lines, respectively.

Lines

Article number, page 5 of 20

solute calibration uncertainties of ALMA). These values werefrom the integrated fluxes and they reflect the average
半径〜130 auの lled disk, computed
DCO+で〜20
au
でgapが見える
spectral index in the disk only, but the spectral index is expected
to vary spatially as a result of factors such as radial changes in the
ケプラー回転から中心星質量~1.3Msun
optical depth and grains sizes. To investigate such spatial variations, we combined the resolved 1.3 mm and 2.2 mm observa12COから aring の兆候や裏面が見えない→幾何的に薄い
tions to produce a resolved map of the spectral index. During thisprocess,the most extendedMsun
configuration of the available Band 6
COから見積もったgas mass
10^-4~10^-3
data was excluded to avoid problems with very di↵erent coverage of the uv-planedi↵erent bands. The 1.3 and 2.2 mm data Fig. 4. Derived millimeter spectral index for MP Mus between 1.3 andgas/dust ~1-10 gasのdissipation?
COatabundance?
were jointly imaged with the tclean algorithm, the mtmfs de- 2.2 mm. Top: Spectral index map. Only pixels with S/N>5 are considered. The solid and dashed contours correspond to ↵1.3 2.2 mm of 2 andconvolver, and nterms=2, and we then used the resulting alpha 2.5, respectively. The image beam is shown on the bottom left corner.
image as the spectral index map. After various tests we adopted Bottom: Corresponding de-projected ↵1.3 2.2 mm radial profile and una robust parameter of 0.0 in this case, which yielded a beam of certainties (solid red line and area). The beam FWHM is shown as a0.200 ⇥0.1700 . The derived spectral index map and its radial pro- horizontal red line. The dashed line marks the ↵ = 2 transition.
ダストにgap構造が見えないのに、large
dustが残っている。光学的厚みかresolutionの問題で見えないbump?
file are shown in Fig. 4. As expected, the value of ↵1.3 2.2 mm is
not constantthroughout
the disk and increases as a function of
惑星質量に上限(~0.5-4Mj forr>10
au)
radius, ranging from ⇠1.7 in the inner regions to ⇠3 in the outer moments are listed in Table 6. Note that each project used different antenna and correlator configurations, so the spectral and
parts
of
the
disk.
These
resultsarediscussedinfurther
detailin
散乱光のgapは内側でpu ed up したinner rimが作る影
spatial resolutions are di↵erent for each line (also listed in TaSec. 4.2.
ble 6). In the case of the Band 6 observations, we only used theobservations from project 2017.1.01419.S to generate the cubes
3.2. Gas lines(data from 2017.1.01167.S have a significantly higher angular
ff

fi

fl

議論

nurseries: vortices formed at smooth viscosity transition
44 Planetary
Zs. Regaly, K. Kadam, D. Tarczay-Nehez F Excitation of Rossby wave instability and development of a large-scalevortex at the outer dead zone edge of protoplanetary discs is one of the leading theories that explains horseshoe-likebrightness distribution in transition discs. Formation of such vortices requires a relatively sharp viscosity transition.
Detailed modelling, however, indicates that viscosity transitions at the outer edge of the dead zone is relatively smooth.
In this study, we present 2D global, non-isothermal, gas-dust coupled hydrodynamic simulations to investigate thepossibility of vortex excitation at smooth viscosity transitions. Our models are based on a recently postulated scenario,
wherein the recombination of charged particles on the surface of dust grains results in reduced ionisation fraction andin turn the turbulence due to magnetorotational instability. Thus, the alpha-parameter for the disc viscosity depends
on the local dust-to-gas mass ratio. We found that the smooth viscosity transitions at the outer edge of the dead zone
can become Rossby unstable and form vortices. A single large-scale vortex develops if the dust content of the disc iswell coupled to the gas, however, multiple small-scale vortices ensue for the case of less coupled dust. As both typeof vortices are trapped at the dead zone outer edge, they provide suﬃcient time for dust growth. The solid content
collected by the vortices can exceed several hundred Earth masses, while the dust-to-gas density ratio within often
exceeds unity. Thus, such vortices function as planetary nurseries within the disc, providing ideal sites for formationof planetesimals and eventually planetary systems.

Direct imaging discovery of a super-Jovian around the young Sun-like star AF Leporis

Robert J. De Rosa, Eric L. Nielsen, Zahed Wahhaj, Jean-Baptise Ruﬃo, Paul G. Kalas, Anne E. Peck, Lea
A. Hirsch, William Roberson F (abridged) Expanding the sample of directly imaged companions to nearby, youngstars that are amenable to detailed astrometric and spectroscopic studies is critical for the continued development andvalidation of theories of their evolution and atmospheric processes. The recent release of the Gaia astrometric catalogue
allows us to eﬃciently search for these elusive companions by targeting those stars that exhibit the astrometric reflex
motion induced by an orbiting companion. The nearby (27 pc), young (24 Myr) star AF Leporis (AF Lep) was
targeted because of its astrometric acceleration, consistent with a wide-orbit planetary companion detectable withhigh-contrast imaging. We used the SPHERE instrument on the VLT to search for faint substellar companions in theimmediate vicinity of AF Lep. We used observations of a nearby star interleaved with those of AF Lep to eﬃciently
subtract the residual point spread function. This provided sensitivity to faint planetary-mass companions within 1
arcsec (⇠30 au) of the star. We detected the companion AF Lep b at a separation of 339 mas (9 au), within the inneredge of its unresolved debris disk. The measured K-band contrast and the age of the star yield a model-dependent

dze

dze

in the U-prescription (Lyra et al. 2009b; Regály et al. 2012), which
es of Rossby wave instability(RWI)
is sharper than it is expected to form at the outer dead zone edge
ed in 観測されている渦構造の起源として有力視(Dzyurkevich et al. 2013). In our standard models, we assume that
ortex
'
=
0.2,
which
corresponds
to
'
=
(2
+
2/3)
.
To
dze
dze
dze
17b; dead zone outer boundary でのαの変化で引き起こせるか？
extend our investigation, we run models with 'dze = 4 dze forαの変化のスケールが<2Hで急に変われば不安定化できるが、certain cases. Note that the total width of the viscosity transition
to to dead zone outer boundary ではより緩やかにしか変化しない。
given by Equation (14) is about 2 'dze , which corresponds to 0.4
oling
and
0.6
in
the
standard
andextendedscenarios,
respectively.
elled 本研究
Additionally, the global viscosity is modified such that a change
Planetary nurseries 3
Les αのガス、ダスト面密度依存を考慮したモデルでRWIを起こせるか？
in the dust or gas concentration alters the viscosity. According to
2Dのガス・ダスト２成分のシミュレーションで調べる。
12 Zs. Regály,
K. Kadam & D. Tarczay-Nehéz
Dullemonda parametricU-prescription
can beravitational
potentialof the star &in aPenzlin
Table(2018)
1. Investigatedparametric–U models.
e A. Since the equations
are solved in
given
as
αのモデル
tem
model
qd
qg
(10)centred on the star, Equation (7)

(11)

´ d

´ g

case Acase Bcase Ccase Dcase E

0
-1
-1
-2
-1

-1
0
1
1
-1

10 -4

Σ

ct potential, ind (A, q) arising due to qd
qg
entre of the system caused by any
disc
⌃g ™
⌃
©
©
™
d
ortancein, e.g., Mittal
ChiangU=&
Ubg,≠ 2015;
≠
Æ̈
Æ̈
s
(0)
(0)
ly & Vorobyov 2017a). The ⌃indirect
⌃

(15)

10 -5

10 -6

(0)
(0)
where ⌃g andaretheinitial
gas
and
dust
densities.
Valuesr,(8) ⌃dα̲bg ：ΔR=(2+2/3)Hordead4Hでなだらかに変化
at
disc
zone
the backgroundviscosity,
viscosity, UbgUis definedas 2 ,
mical
of
U
are
limitedbetweenthebackground=10
bg
dinate system can be given as✓◆4y we ’
1'. The'dze assumption of
結論：φ<0の時、Σgの揺らぎが>0の時（ダストの濃集を通して）
0
0
and
the
MRI
inactiveviscosity,U=10m 9 ,:(1 Udead) 1 tanh
Ubg = 1,(14)
modcos(q )⌧
cos(q 0 )
0

0.5

1.0

R

2
'dze
:
ating: 0 0 minimum
02
A9
effective viscosity is consistent withthe vertical shear
αが減少、さらにΣgが大きくなるpositive
feadback
9 ,:
The
outer
edge
of
the
disc
dead
zone
is
set
to
'
=
1.5.
Excitationdzempor- ’ minstability
9 0 ,: 0generatedviscosity(Stoll&
Kley2014).
With
regards
toof RWI requires a sharp viscosity transition ( 'dze  2 dze , where→急なαの変化が実現してRWIが成長
n(q : )⌧ 02 sin(q : 0 ),(9)etsch 9 0 ,: 0 Athevalues for qd and dze
qg =weinvestigatedfourcases,
Tablereduction),1'dze⌘ is the disc scaleheightat thesee
viscosity
9in the U-prescription (Lyra et al. 2009b; Regály et al. 2012), which
s not

2.5

5.0

nre
te
s

4)

=
=
mer
es
nhe
ch

a
th
of
ns
he
is
d.
ns.
in
es
ry
ge

o,
le
th
eon
or
le

シミュレーション結果

sedimentation for the dust, in which case,Table
2. Summary on the vortexA2excitation in models listed
in Table 1. MarkA1
A3
ing "5" corresponds to the absent of the given vortex type being multiplersmall-scale or single large-scale. jmin values show the minimum (i.e., theU.
(23)strongest phase) of vortex aspect ratio for gas/dust components, respectively.
d = g
St + U
ガス質量~2Mj
jmin values in parenthesis represents the minimum value reached by the endof simulation. The last column lists the maximum value of total midplane
ダスト質量
St=10^-1,
10^-2で100,
10Me
density in terms of Roche density at that radius. Models with asterisk use
The fragmentation size, 0 frag , is the maximum size of solid conextra wide 'dze = 4 dze viscosity transition.
stituent that can be reached due todust growth process,beforeSt=10^-2でdust/gas> the
1→streaming
instability

大きい渦

the grown particles are destroyed via mutual collision. We calculate
St=10^-1でRoch
を超える→重力崩壊可能(？)
the dust grain fragmentationdensity
according toBirnstiel et al. (2012) as

破壊で決まるダストサイズは ~6-12cm
2⌃g E 2frag
0 frag =,2
3cds U2 s

(24)

Mod.

St

A1
A2A5
A3
A4
A5
A5*

1
10 10
10 2
10 3
10 4
10 5
10 5

with the typical assumptions of fragmentation velocity, E frag =10 m s 1 , and the internal density of the dust aggregate, ds =B1
10 1
1.6 g cm 3 . The value of U is self-consistently calculated from sim2
ダスト質量
1~10
Me
B2
10
ulations according to Eq. (15) and ⌃g is calculated using the higher
2
B2*
10
bound
for MMSN.> In
the plots, maximuminstability
values of the quantities
dust/gas
1→streaming
B3
10 3
were global maximum throughout the computational grid. The cen4
B4
10
tralガス面密度は大きい渦より小さい
values were averaged across the centre of all the vortices. The
B5
10 5
averagevalue was calculated over the area of all vortices, which
B5*
10 5→ダストサイズは半分程度
gives a lower bound.
B5
1
C1
10
The simulations conducted in this study correspond to a2
C2
10
representative disc, which extends from 0.5 au to 5 au, with
3
C3
10
・どちらの場合でも渦の落下はdead
zone
outer
the outer boundary of the dead zone set at a radial
distanceof edge でC3*
10 3'dze = '0 = 1 au. In a typical protoplanetary disc, the dimensions
止まる
C4
10 4
are about an order of magnitude larger, with the outer edge of theC5
10 5
dead zone lying at about 15 au. However, since the self-gravity is→微惑星・惑星形成環境として有望
D1
10 1
not considered in our simulations, the disc can be spatially rescaled.
D2
10 2
In this process, we keep the gas surface density values at 1 au un-

小さい渦

Small
vort.

Large
vort.

CRWI
( #orb )jmin(dust/gas)

A4

dtot /dRoche

5 Regály,5K. Kadam- & D. Tarczay-Nehéz
Zs.
5
5
5
5
5

4
A5*
B1 4
4
4
4

350
400
400
400
1500

16/10B3
16/14 C1
15/15
15/15
34/34

7.5 ⇥ 10 2
9.6 ⇥ 10 3
8.6 ⇥ 10 3
8.6 ⇥ 10 3
7.0 ⇥ 10 3

4
4
4
5
5
5
5

5
5
5
4
4
4
4

50
100
100
250
350
350
950

3/7
6/6
5/5
10/10
14/14
15/15
32/32

4.9
3.6 ⇥ 10 2
3.4 ⇥ 10 2
1.2 ⇥ 10 2
9.0 ⇥ 10 3
8.7 ⇥ 10 3
7.2 ⇥ 10 3

4
4
5
5
5
5
4
4

B5*

C3

5
5
4
4
5
5

50
150
650
1350
-

3/7
5/6
9/9
8/8
-

5
5

50
100

3/10
9/9

3.3
3.2 ⇥ 10 2
7.0 ⇥ 10 3
5.1 ⇥ 10 3
4.4
1.2 ⇥ 10 1

B4

C3*

D1

Structure and Kinematics of Sh2-138 – A distant hub-filament system in the outer
31 Galactic plane
Kshitiz Mallick, Lokesh Dewangan, Devendra Ojha, Tapas Baug, Igor Zinchenko F We present a molecularline study of the Sh2-138 (IRAS 22308+5812) hub-filament system with an aim to investigate its structure andkinematics. Archival CO molecular line data from the Canadian Galactic Plane Survey (CO(J=1-0)) for the wider
region (50arcminx50arcmin) and the James Clerk Maxwell Telescope (CO(3-2), 13CO(3-2), and C18O(3-2)) for thecentral portion (5arcminx5arcmin) have been utilised. Analysis of the CO(1-0) spectra for the extended region in
conjunction with the hub and filament identification using column density map and the getsf tool, respectively, reveals
a complex structure with the spectral extraction for the central position displaying multiple velocity components.
Based on the Herschel 70 micron warm dust emission, one of the filaments in the extended region was inferred to be
associated with active star formation, and is host to a Bolocam 1.1 mm clump of 1606 Msun. Integrated intensity mapof 13CO(3-2) emission, constructed from clumps detected at above 5sigma in position-position-velocity space, reveals
three filamentary structures (labelled W-f, SW-f, and SE-f) in the central portion. Velocity gradients observed in
13CO(3-2) position-velocity slices point to longitudinal gas flow along the filaments into the central region. Filaments
W-f, SW-f, and SE-f were calculated to have observed line masses of 32, 33.5, and 50 Msun/pc , respectively. The
cloud was found to be dominated by supersonic and non-thermal motions, with high Mach numbers (>3) and low
thermal to non-thermal pressure ratio (0.01-0.1).

11

Disk
fragmentation
aroundamassive
protostar:a
comparisonoftwothree-dimensional
32 codesRaphaël Mignon-Risse, André Oliva, Matthias González, Rolf Kuiper, Benoît Commerçon F (Abridged) Most

massive stars are located in multiple systems. The modeling of disk fragmentation, a possible mechanism leading tostellar multiplicity, relies on parallel 3D simulation codes whose agreement remains to be evaluated. Using the Cartesian
AMR code RAMSES, we compare disk fragmentation in a centrally-condensed protostellar system to the study of Oliva& Kuiper (2020) performed on a grid in spherical coordinates using PLUTO. Two RAMSES runs are considered andgive qualitatively distinct pictures. When allowing for unlimited sink particle creation, gas fragmentation leads to a
multiple stellar system whose multiplicity is aﬀected by the grid when triggering fragmentation and by numericallyassisted mergers. On the other hand, using a unique, central, fixed sink particle, a centrally-condensed system forms,
similar to that reported in PLUTO. The RAMSES-PLUTO comparison is performed with the latter: agreement
between the two codes is found regarding the first rotationally-supported disk formation, the presence of an accretion
shock onto it, the first fragmentation phase. Gaseous fragments form and their properties are in agreement between
the two codes. As a minor diﬀerence, fragments dynamics causes the disk structure to be sub-Keplerian in RAMSES
whereas it is found to be Keplerian and reaches quiescence in PLUTO. We attribute this discrepancy to the central star
being twice less massive in RAMSES because of the diﬀerent stellar accretion subgrid models. In a centrally-condensed
system, the agreement between RAMSES and PLUTO regarding many of the collapse properties and fragmentation
process is good. Fragmentation occurring in the innermost region and numerical choices (use of sink particles, grid)
have a crucial impact when similar but smooth initial conditions are employed - more crucial than the code’s choice on the system’s outcome, multiple or centrally-condensed.

A CCD Search for Variable Stars in the Open Cluster NGC 6611

G. Michalska, Z. Kołaczkowski, R. Leiton, O. Szewczyk, K. Kinemuchi, V., M. Kalari F We present the resultsof the U BV IC variability survey in the young open cluster NGC 6611 based on observations obtained during 34 nights
spanning one year. In total, we found 95 variable stars. Most of these stars are classified as periodic and irregularpre-main sequence (PMS) stars. The analysis of the JHKS 2MASS photometry and four-colour IRAC photometry
revealed 165 Class II young stellar sources, 20 of which are irregular variables and one is an eclipsing binary. These
classifications, complemented by JHK UKIDSS photometry and riH↵ VPHAS photometry, were used to identify
24 candidates for classical T Tauri stars and 30 weak-lined T Tauri stars. In addition to the PMS variables, weSpiral Structure and Massive Star formation in the Hub-Filament-System G326.27-0.49

34 Bhaswati Mookerjea, V. S. Veena, Rolf Guesten, F. Wyrowski, Akhil Lasrado F Hub-filament systems (HFSs) arepotential sites of formation of star clusters and high mass stars. To understand the HFSs and to provide observational
constraints on current theories that attempt to explainstar formation globally, we report a study of the region associatedwith G326.27-0.49 using infrared data of dust continuum and newly obtained observations on molecular tracers using
the APEX telescope. We use the spectroscopic observations to identify velocity-coherent structures (filaments andclumps) and study their properties at a resolution of 0.4 pc. The region contains two main velocity components: firstcomponent shows four filaments between -63 and -55 km/s forming a spiral structure converging in a hub, the second
filamentary component at -72 km/s harbors a massive young stellar object and possibly interacts with the hub. The
clumps harbouring the three main YSOs in the region are massive (187-535 Msun), have luminosities consistent with
B-type stars, have central densities of 106 cm 3 and drive large outflows. Majority of the velocity-coherent clumps
in the region show virial parameters between 2-7, which considering the detection of protostars implies collapse to be
gradual. We conclude that the region consists of a network of filaments through which mass accretes ( 10 4 Msun/yr)
onto the hub. The hub and some of the ends of filaments appear to be undergoing collapse to form new stars. This
study identifies a target region for future high resolution observations that could probe the link between the core andfilament evolution.

12

Investigating the morphology and CO gas kinematics of Sh2-112 region

35 Kshitiz Mallick, Saurabh Sharma, Lokesh Dewangan, Devendra Ojha, Neelam Panwar, Tapas Baug F We

present a study of the molecular cloud in Sh2-112 massive star forming region using the 3-2 transition of CO isotopologues - CO, 13CO, and C18O; supplemented in part by CGPS HI line emission and MSX data. Sh2-112 is an
optically visible region powered by an O8V type massive star BD +45 3216, and hosts two Red MSX Survey sources G083.7962+03.3058 and G083.7071+03.2817 - classified as HII region and young stellar object, respectively. Reduced
spectral data products from the James Clerk Maxwell Telescope archive, centered on the two RMS objects with 7’x7’
field of view each, were utilised for the purpose. The 13CO(3-2) channel map of the region shows the molecular
cloud to have filamentary extensions directed away from the massive star, which also seems to be at the edge of acavity like structure. Multiple molecular cloud protrusions into this cavity structure host local peaks of emission.
The integrated emission map of the region constructed from only those emission clumps detected above 5 level inthe position-position-velocity space aﬃrms the same. MSX sources were found distributed along the cavity boundary
where the gas has the been compressed. Spectral extraction at these positions yielded high Mach numbers and low
ratios of thermal to non-thermal pressure, suggesting a dominance of supersonic and non-thermal motion in the cloud.

Takeout and Delivery: Erasing the Dusty Signature of Late-stage Terrestrial Planet
Formation
Joan R. Najita, Scott J. Kenyon F The formation of planets like Earth is expected to conclude with a series oflate-stage giant impacts that generate warm dusty debris, the most anticipated visible signpost of terrestrial planet
formation in progress. While there is now evidence that Earth-sized terrestrial planets orbit a significant fraction ofsolar-type stars, the anticipated dusty debris signature of their formation is rarely detected. Here we discuss several
ways in which our current ideas about terrestrial planet formation imply transport mechanisms capable of erasing the
anticipated debris signature. A tenuous gas disk may be regenerated via "takeout" (i.e., the liberation of planetaryatmospheres in giant impacts) or "delivery" (i.e., by asteroids and comets flung into the terrestrial planet region) at
a level suﬃcient to remove the warm debris. The powerful stellar wind from a young star can also act, its delivered
wind momentum producing a drag that removes warm debris. If such processes are eﬃcient, terrestrial planets may
assemble inconspicuously, with little publicity and hoopla accompanying their birth. Alternatively, the rarity of warm
excesses may imply that terrestrial planets typically form very early, emerging fully formed from the nebular phasewithout undergoing late-stage giant impacts. In either case, the observable signposts of terrestrial planet formation

ratios of thermal to non-thermal pressure, suggesting a dominance of supersonic and non-thermal motion in the cloud.

and Delivery: Erasing the Dusty Signature of Late-stage Terrestrial Planet
36 Takeout
Formation
Joan R. Najita, Scott J. Kenyon F The formation of planets like Earth is expected to conclude with a series oflate-stage giant impacts that generate warm dusty debris, the most anticipated visible signpost of terrestrial planet
formation in progress. While there is now evidence that Earth-sized terrestrial planets orbit a significant fraction ofsolar-type stars, the anticipated dusty debris signature of their formation is rarely detected. Here we discuss several
ways in which our current ideas about terrestrial planet formation imply transport mechanisms capable of erasing the
anticipated debris signature. A tenuous gas disk may be regenerated via "takeout" (i.e., the liberation of planetaryatmospheres in giant impacts) or "delivery" (i.e., by asteroids and comets flung into the terrestrial planet region) at
a level suﬃcient to remove the warm debris. The powerful stellar wind from a young star can also act, its delivered
wind momentum producing a drag that removes warm debris. If such processes are eﬃcient, terrestrial planets may
assemble inconspicuously, with little publicity and hoopla accompanying their birth. Alternatively, the rarity of warm
excesses may imply that terrestrial planets typically form very early, emerging fully formed from the nebular phasewithout undergoing late-stage giant impacts. In either case, the observable signposts of terrestrial planet formation
appear more challenging to detect than previously assumed. We discuss observational tests of these ideas.

Early water delivery to terrestrial planet regions during the stages of Jupiter’s formationand migration in the Grand Tack model

Masahiro Ogihara, Hidenori Genda, Yasuhito Sekine F The formation and subsequent migration of gas giants could

significantly aﬀect the material mixing in the Solar System. In this study, we use N-body simulations to investigate
how much water is transported into the region of the terrestrial planet formation during the growth and migration
phases of Jupiter in the Grand Tack model. We found that Jupiter’s growth was accompanied by significant masstransport, and that a substantial amount of water (about 10 times Earth’s ocean mass for the initial planetesimal
distribution based on the minimum-mass solar nebula) was transported into the terrestrial planet region. The total
amount delivered increased further during Jupiter’s migration phase (totaling about 10-40 times Earth’s ocean mass),
which was less dependent on simulation parameters. In addition, at these stages, terrestrial planets were not fullygrown. Therefore, water supplied during these early stages could interact with metallic iron during the core formationof protoplanets and/or growing Earth. Since hydrogen in water molecules can dissolve into their cores, this could
explain the density deficit observed in the current Earth core. Notably, Jupiter could play an important role as a

(CC) meteorites. This study’s results show that Jupiter’s growth necessitates some mixing of NC and CC materials.

38

ALMA Band 6 high-resolution observations of the transitional disk around SY Cha

Ryuta Orihara, Munetake Momose, Takayuki Muto, Jun Hashimoto, Hauyu Baobab Liu, Takashi Tsukagoshi, Tomoyuki Kudo, Sanemichi Takahashi, Yi Yang, Yasuhiro Hasegawa, Ruobing Dong, Mihoko Konishi,
Eiji Akiyama F In this study, we reported the results of high-resolution (0.14 arcsec) Atacama Large Millime-

ter/submillimeter Array (ALMA) observations of the 225 GHz dust continuum and CO molecular emission lines fromthe transitional disk around SY Cha. Our high-resolution observations clearly revealed the inner cavity and the central
point source for the first time. The radial profile of the ring can be approximated by a bright narrow ring superimposedon a fainter wide ring. Furthermore, we found that there is13a weak azimuthal asymmetry in dust continuum emission.
For gas emissions, we detected 12 CO(2 1), 13 CO(2 1) and C18 O(2 1), from which we estimated the total gas massof the disk to be 2.2 ⇥ 10 4 M , assuming a CO/H2 ratio of 10 4 . The observations showed that the gas is present
inside the dust cavity. The analysis of the velocity structure of the 12 CO(2 1) emission line revealed that the velocity
is distorted at the location of the dust inner disk, which may be owing to warping of the disk or radial gas flow within
the cavity of the dust disk. High-resolution observations of SY Cha showed that this system is composed of a ring anda distorted inner disk, which may be common, as indicated by the survey of transitional disk systems at a resolutionof ⇠0.1 arcsec.

Survey of H↵ emission-line stars in the star-forming region IC 5070

Neelam Panwar, Jessy Jose, Rishi C F Actively accreting young stellar objects show H↵ emission line in theirspectra. We present the results of survey for H↵ emission-line stars in the star-forming region IC 5070 taken with
2-m Himalyan Chandra Telescope. Based on the H↵ slitless spectroscopy data, we identified 131 emission-line stars in⇠ 0.29 square degrees area of the IC 5070 region. Using Gaia Early Data Release 3, we estimated the mean propermotion and parallax of the emission-line stars. We also estimated the mean distance and reddening toward the region
using the emission-line stars, that are ⇠ 833 pc and ⇠2 mag, respectively. By examining the locations of these stars
in the color-magnitude diagrams constructed using Gaia and PanSTARRS1 data, we found that a majority of the H↵
emitters are young low-mass (< 1.5 M ) stars. We also compared our catalog of emission-line stars with the available
young stellar catalogs and found that most of them are Class II/ flat spectrum sources with the spectral type ranging
from K to M. Based on the proper motion/ parallax values and locations on the color-magnitude diagrams, about 20
emission-line stars are flagged as non-members. The relative proper motion of the emission-line stars with respect tothe ionizing source suggest the possibility of the ‘rocket eﬀect’ scenario in the remnant cloud (BRC 31).

of ⇠0.1 arcsec.

of H↵ emission-line stars in the star-forming region IC 5070
39 Survey
Neelam Panwar, Jessy Jose, Rishi C F Actively accreting young stellar objects show H↵ emission line in theirspectra. We present the results of survey for H↵ emission-line stars in the star-forming region IC 5070 taken with
2-m Himalyan Chandra Telescope. Based on the H↵ slitless spectroscopy data, we identified 131 emission-line stars in⇠ 0.29 square degrees area of the IC 5070 region. Using Gaia Early Data Release 3, we estimated the mean propermotion and parallax of the emission-line stars. We also estimated the mean distance and reddening toward the region
using the emission-line stars, that are ⇠ 833 pc and ⇠2 mag, respectively. By examining the locations of these stars
in the color-magnitude diagrams constructed using Gaia and PanSTARRS1 data, we found that a majority of the H↵
emitters are young low-mass (< 1.5 M ) stars. We also compared our catalog of emission-line stars with the available
young stellar catalogs and found that most of them are Class II/ flat spectrum sources with the spectral type ranging
from K to M. Based on the proper motion/ parallax values and locations on the color-magnitude diagrams, about 20
emission-line stars are flagged as non-members. The relative proper motion of the emission-line stars with respect tothe ionizing source suggest the possibility of the ‘rocket eﬀect’ scenario in the remnant cloud (BRC 31).

Extension of HOPS Out to 500 ParSecs (eHOPS). I. Identification and Modeling ofProtostars in the Aquila Molecular Clouds

Riwaj Pokhrel, S. Thomas Megeath, Robert A. Gutermuth, Elise Furlan, William J. Fischer, Samuel Federman,
John J. Tobin, Amelia M. Stutz, Lee Hartmann, Mayra Osorio, Dan M. Watson, Thomas Stanke, P. Manoj,
Mayank Narang, Prabhani Atnagulov, Nolan Habel, Wafa Zakri F We present a Spitzer/Herschel focused surveyof the Aquila molecular clouds (d ⇠ 436 pc) as part of the eHOPS (extension of HOPS Out to 500 ParSecs) census
of nearby protostars. For every source detected in the Herschel/PACS bands, the eHOPS-Aquila catalog contains 1850 µm SEDs assembled from 2MASS, Spitzer, Herschel, WISE, and JCMT/SCUBA-2 data. Using a newly developed
set of criteria, we classify objects by their SEDs as protostars, pre-ms sequence stars with disks, and galaxies. A totalof 172 protostars are found in Aquila, tightly concentrated in the molecular filaments that thread the clouds. Of these,
71 (42%) are Class 0 protostars, 54 (31%) are Class I protostars, 43 (25%) are flat-spectrum protostars, and 4 (2%)
are Class II sources. Ten of the Class 0 protostars are young PACS Bright Red Sources similar to those discovered inOrion. We compare the SEDs to a grid of radiative transfer models to constrain the luminosities, envelope densities,
and envelope masses of the protostars. A comparison of the eHOPS-Aquila to the HOPS protostars in Orion finds thatthe protostellar luminosity functions in the two star-forming regions are statistically indistinguishable, the bolometrictemperatures/envelope masses of eHOPS-Aquila protostars are shifted to cooler temperatures/higher masses, and the

the ionizing source suggest the possibility of the ‘rocket eﬀect’ scenario in the remnant cloud (BRC 31).

40

Extension of HOPS Out to 500 ParSecs (eHOPS). I. Identification and Modeling ofProtostars in the Aquila Molecular Clouds

Riwaj Pokhrel, S. Thomas Megeath, Robert A. Gutermuth, Elise Furlan, William J. Fischer, Samuel Federman,
John J. Tobin, Amelia M. Stutz, Lee Hartmann, Mayra Osorio, Dan M. Watson, Thomas Stanke, P. Manoj,
Mayank Narang, Prabhani Atnagulov, Nolan Habel, Wafa Zakri F We present a Spitzer/Herschel focused surveyof the Aquila molecular clouds (d ⇠ 436 pc) as part of the eHOPS (extension of HOPS Out to 500 ParSecs) census
of nearby protostars. For every source detected in the Herschel/PACS bands, the eHOPS-Aquila catalog contains 1850 µm SEDs assembled from 2MASS, Spitzer, Herschel, WISE, and JCMT/SCUBA-2 data. Using a newly developed
set of criteria, we classify objects by their SEDs as protostars, pre-ms sequence stars with disks, and galaxies. A totalof 172 protostars are found in Aquila, tightly concentrated in the molecular filaments that thread the clouds. Of these,
71 (42%) are Class 0 protostars, 54 (31%) are Class I protostars, 43 (25%) are flat-spectrum protostars, and 4 (2%)
are Class II sources. Ten of the Class 0 protostars are young PACS Bright Red Sources similar to those discovered inOrion. We compare the SEDs to a grid of radiative transfer models to constrain the luminosities, envelope densities,
and envelope masses of the protostars. A comparison of the eHOPS-Aquila to the HOPS protostars in Orion finds thatthe protostellar luminosity functions in the two star-forming regions are statistically indistinguishable, the bolometrictemperatures/envelope masses of eHOPS-Aquila protostars are shifted to cooler temperatures/higher masses, and theeHOPS-Aquila protostars do not show the decline in luminosity with evolution found in Orion. We briefly discuss
whether these diﬀerences are due to biases between the samples, diverging star formation histories, or the influence ofenvironment on protostellar evolution.

Starlight-polarization-based tomography of the magnetized interstellar medium: PASIPHAE’sline-of-sight inversion method
V. Pelgrims, G. V. Panopoulou, K. Tassis, V. Pavlidou, A. Basyrov, D. Blinov, E. Gjerløw, S. Kiehlmann, N.
Mandarakas, A. Papadaki, R. Skalidis, A. Tsouros, R. M. Anche, H. K. Eriksen, T. Ghosh, J. A. Kypriotakis, S.
Maharana, E. Ntormousi, T. J. Pearson, S. B. Potter, A. N. Ramaprakash, A. C. S. Readhead, I. K. Wehus F

We present the first Bayesian method for tomographic decomposition of the plane-of-sky orientation of the magnetic
field with the use of stellar polarimetry and distance. This standalone tomographic inversion method presents anenvironment on protostellar evolution.

tomography of the magnetized interstellar medium: PASIPHAE’s
41 Starlight-polarization-basedline-of-sight inversion method
V. Pelgrims, G. V. Panopoulou, K. Tassis, V. Pavlidou, A. Basyrov, D. Blinov, E. Gjerløw, S. Kiehlmann, N.
Mandarakas, A. Papadaki, R. Skalidis, A. Tsouros, R. M. Anche, H. K. Eriksen, T. Ghosh, J. A. Kypriotakis, S.
Maharana, E. Ntormousi, T. J. Pearson, S. B. Potter, A. N. Ramaprakash, A. C. S. Readhead, I. K. Wehus F

We present the first Bayesian method for tomographic decomposition of the plane-of-sky orientation of the magnetic
field with the use of stellar polarimetry and distance. This standalone tomographic inversion method presents animportant step forward in reconstructing the magnetized interstellar medium (ISM) in 3D within dusty regions. We
develop a model in which the polarization signal from the magnetized and dusty ISM is described by thin layers at
various distances. Our modeling makes it possible to infer14the mean polarization (amplitude and orientation) induced
by individual dusty clouds and to account for the turbulence-induced scatter in a generic way. We present a likelihood
function that explicitly accounts for uncertainties in polarization and parallax. We develop a framework for reconstructing the magnetized ISM through the maximization of the log-likelihood using a nested sampling method. We
test our Bayesian inversion method on mock data taking into account realistic uncertainties from Gaia and as expected
for the optical polarization survey PASIPHAE according to the currently planned observing strategy. We demonstratethat our method is eﬀective at recovering the cloud properties as soon as the polarization induced by a cloud to its
background stars is higher than ⇠ 0.1% for the adopted survey exposure time and level of systematic uncertainty. Our
method makes it possible to recover not only the mean polarization properties but also to characterize the intrinsic
scatter, thus creating new ways to characterize ISM turbulence and the magnetic field strength. Finally, we apply
our method to an existing data set of starlight polarization with known line-of-sight decomposition, demonstrating
agreement with previous results and an improved quantification of uncertainties in cloud properties.

The ALMA view of MP Mus (PDS 66): a protoplanetary disk with no visible gaps
down to 4 au scales

Á. Ribas, E. Macías, P. Weber, S. Pérez, N. Cuello, R. Dong, A. Aguayo, C. Cáceres, J. Carpenter, W. R. F.
Dent, I. de Gregorio-Monsalvo, G. Duchêne, C. C. Espaillat, P. Riviere-Marichalar, M. Villenave F We present

ALMA multiwavelength observations of the protoplanetary disk around the nearby (d⇠100 pc) young solar analog MP
Mus (PDS 66). These observations at 0.89 mm, 1.3 mm, and 2.2 mm have angular resolutions of ⇠ 1", 0.05", and 0.25",
respectively, and probe the dust and gas in the system with unprecedented detail and sensitivity. The disk appears
smooth down to the 4 au resolution of the 1.3 mm observations, in contrast with most disks observed at comparable
spatial scales. The dust disk has a radius of 60±5 au, a dust mass of 0.14+0.11
0.06 MJup , and a mm spectral index < 2in the inner 30 au, suggesting optically thick emission from grains with high albedo in this region. Several molecularbetween 30-80 au is likely not a gap in the disk density, but a shadow cast by a puﬀed-up inner disk.

constraints on turbulence in proto-planetary discs
43 Empirical
Giovanni P. Rosotti F Proto-planetary discs, the birth environment of planets, are an example of a structure com-monly found in astrophysics, accretion discs. Identifying the mechanism responsible for accretion is a long-standing
problem, dating back several decades. The common picture is that accretion is a consequence of turbulence, withseveral instabilities proposed for its origin. While traditionally this field used to be a purely theoretical endeavour,the landscape is now changing thanks mainly to new observational facilities such as the ALMA radio interferometer.
Thanks to large improvements in spatial and spectral resolution and sensitivity (which have enabled the study of discsubstructure, kinematics and surveys of large disc populations), multiple techniques have been devised to observationally measure the amount of turbulence in discs. This review summarises these techniques, ranging from attempts at
direct detection of turbulence from line broadening, to more indirect approaches that rely on properties of the dust or
consider the evolution of global disc properties (such as masses, radii and accretion rates) for large samples, and what
their findings are. Multiple lines of evidence suggest that discs are in fact not as turbulent as thought one decade ago.
On the other hand, direct detection of turbulence in some discs and the finite radial extent of dust substructures and insome cases the finite vertical extent strongly indicate that turbulence must be present at some level in proto-planetary
discs. It is still an open question whether this amount of turbulence is enough to power accretion or if this is instead
driven by other mechanisms, such as MHD winds.

15

of planetesimals and eventually planetary systems.

45

Direct imaging discovery of a super-Jovian around the young Sun-like star AF Leporis

Robert J. De Rosa, Eric L. Nielsen, Zahed Wahhaj, Jean-Baptise Ruﬃo, Paul G. Kalas, Anne E. Peck, Lea
A. Hirsch, William Roberson F (abridged) Expanding the sample of directly imaged companions to nearby, youngstars that are amenable to detailed astrometric and spectroscopic studies is critical for the continued development andvalidation of theories of their evolution and atmospheric processes. The recent release of the Gaia astrometric catalogue
allows us to eﬃciently search for these elusive companions by targeting those stars that exhibit the astrometric reflex
motion induced by an orbiting companion. The nearby (27 pc), young (24 Myr) star AF Leporis (AF Lep) was
targeted because of its astrometric acceleration, consistent with a wide-orbit planetary companion detectable withhigh-contrast imaging. We used the SPHERE instrument on the VLT to search for faint substellar companions in theimmediate vicinity of AF Lep. We used observations of a nearby star interleaved with those of AF Lep to eﬃciently
subtract the residual point spread function. This provided sensitivity to faint planetary-mass companions within 1
arcsec (⇠30 au) of the star. We detected the companion AF Lep b at a separation of 339 mas (9 au), within the inneredge of its unresolved debris disk. The measured K-band contrast and the age of the star yield a model-dependent
mass of 4 and 6 MJup , consistent with the mass derived from an orbital fit of 4.3+2.9
1.2 MJup . The near-infrared SEDof the planet is consistent with an object at the L–T spectral type transition, but under-luminous with respect tofield-gravity objects. AF Lep b joins a growing number of substellar companions imaged around stars in the young
Pic moving group. With a mass of between 3 and 7 MJup , it occupies a gap in this isochronal sequence between
the hotter, more massive companions like PZ Tel B and Pic b, and the cooler 51 Eri b, which is suﬃciently cool formethane to form within its photosphere.

Analysis of the first infrared spectrum of quasi-bound H2 line emission in Herbig-Haro7

Evelyne Roueﬀ, Michael G. Burton, Thomas R. Geballe, Hervé Abgrall F Context. Highly excited molecularhydrogen H2 has been observed in many regions of shocked molecular gas. A recently published K-band spectrum of
Herbig-Haro 7 (HH7) contains several vibration-rotation lines of H2 from highly excited energy levels that have notbeen detected elsewhere, including a line at 2.179 µm identified as arising from the v=2 J=29 level, which lies above
the dissociation limit of H2. One emission line at 2.104 µm in this spectrum was unidentified. Aims. We aim tocomplete the analysis of the spectrum of HH7 by including previously missing molecular data that have been recently
computed. Methods. We re-analysed the K-band spectrum, emphasising the physics of quasi-bound upper levels thatmethane to form within its photosphere.

46 Analysis of the first infrared spectrum of quasi-bound H2 line emission in Herbig-Haro7

Evelyne Roueﬀ, Michael G. Burton, Thomas R. Geballe, Hervé Abgrall F Context. Highly excited molecularhydrogen H2 has been observed in many regions of shocked molecular gas. A recently published K-band spectrum of
Herbig-Haro 7 (HH7) contains several vibration-rotation lines of H2 from highly excited energy levels that have notbeen detected elsewhere, including a line at 2.179 µm identified as arising from the v=2 J=29 level, which lies above
the dissociation limit of H2. One emission line at 2.104 µm in this spectrum was unidentified. Aims. We aim tocomplete the analysis of the spectrum of HH7 by including previously missing molecular data that have been recently
computed. Methods. We re-analysed the K-band spectrum, emphasising the physics of quasi-bound upper levels thatcan produce infrared emission lines in the K band. Results. We confirm the identification of the 2 1 S(27) line
at 2.1785 µm and identify the line at 2.1042 µm as due to the 1-0 S(29) transition of H2, whose upper level energy
is also higher than the dissociation limit. This latter identification, its column density, and the energy of its upper
level further substantiate the existence of a hot thermal component at 5000 K in the HH7 environment. Conclusion.
The presence of the newly identified 1 0 S(29) line, whose quasi-bound upper level (v=1, J=31) has a significant
spontaneous dissociation probability, shows that dissociation of H2 is occurring. The mechanism by which virtually
all of the H2 levels with energies from 20,000 K to 53,000 K is maintained in local thermodynamic equilibrium at asingle temperature of ⇠5,000 K remains to be understood.
16

Searching for Molecular Jets from High-Mass Protostars

Tatiana M. Rodriguez, Peter Hofner, Isaac Edelman, Esteban D. Araya, Viviana Rosero F We report Very Large

Array (VLA) observations in the Q-band toward 10 ionized jet candidates to search for SiO emission, a well-known
shocked gas tracer. We detected 7 mm continuum counterparts toward 90% of the jet candidates. In most cases, the jet
candidate is located towIno1(-27(ca)3.2)--311((o)-27(c)-37.711256.1(s)m256.1(s)co)311e-0.463 (ed)-311 yerghatt