Star Formation
Newsletter
速報Seminar
2023/06/30
古屋 玲#364 29-42

まずは紹介しない論⽂の紹介

00Paris, France
5
Observatoire de Paris,
PSL University,
Sorbonne
Université,75014 Paris,
FranceModeling
the early
massejectionLERMA,in jet-driven
protostellar
Accepted January 12, 2022

outflows. Lessons from Cep E.
P. R. Rivera-Ortiz1, 2 , A. de A. Schutzer2 , B. Lefloch2, 3 , and A. Gusdorf4, 5

ABSTRACT
Instituto de Radioastronomı́a y Astrofı́sica, Universidad
Nacional Autónoma de México, P.O. Box 3-72, 58090, Morelia, Michoacán, Mexico
e-mail: p.rivera@irya.unam.mx
Context. Protostellar 2jets
outflows
areInstitut
an important
agentof starde formation
as38000
they
carry away a fraction ofUniv. and
Grenoble
Alpes, CNRS,de Planétologie etd’Astrophysique
Grenoble (IPAG),
Grenoble,
Francemomentum and energy,
whichisneededforgravitational
collapseandprotostellar
massaccretiontooccur.
3
Laboratoire d’Astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, allée Geo↵roy Saint-Hilaire, 33615 Pessac,
Aims. Our goal is to provide
France constraints on the dynamics of the inner protostellar environment from the study of the
4
Laboratoire de Physique de l’ENS, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, 75005
outflow-jet propagationParis,
away
from the launch region.
France5Observatoirede Paris, PSL University,
Sorbonne Université, LERMA,
75014
Paris, France
Methods. We have used
the axisymmetricchemo-hydrodynamicalcode
Walkimya-2D
to numerically model and repro-

1.06146v2 [astro-ph.SR] 4 Feb 2023

1

duce the physical and Accepted
CO emissionof the jet-driven outflow from the intermediate-mass protostar CepE-mm,
January 12,properties
2022
which was observed at ⇠ 800 au resolution in the CO J=2–1 line with the IRAM interferometer. Our simulations take
into account the observational constraints available on ABSTRACT
the physical structure of the protostellar envelope.
Context.
Protostellar jets
and outflows areimportantagent of star andformation
as they carry away
a fraction
Results. Walkimya-2D
successfully
reproduces
theanmain
qualitative
quantitative
featuresofofthe Cep E outflow andmomentum and energy, which is needed for gravitational collapse and protostellar mass accretion to occur.
the jet kinematics, naturally
accounting
for theirtime
variability.
Signaturesof internal
shocksAims. Our goal
is to provide constraints
on thedynamicsof the inner protostellar
environment
from the studyof the are detected as knots
outflow-jet
propagation
away
from the launch
region. the young emitted knots interact with the dense circumstellar
along the jet. In the early
times
of
the
ejectionprocess,
Methods. We have used the axisymmetric chemo-hydrodynamical code Walkimya-2D to numerically model and reproenvelope through high-velocity,
shocks,of whichstrongly
decrease
the COprotostar
gas abundancein the jet. As timeduce the physicaldissociativeand CO emission properties
the jet-driven
outflow fromthe intermediate-mass
CepE-mm,3
which was observed at ⇠ 800 au resolution in the CO J=2–1 line with the IRAM interferometer. Our simulations takeproceeds, the knots propagate
moresmoothly
throughtheenvelopeanddissociative
shocksdisappear
after
⇠
10
yr.
into account the observational constraints available on the physical structure of the protostellar envelope.
Results.
Walkimya-2D
successfully
the mainqualitativeand quantitativeof the Cepoutflowand dissociative phase in
The distribution of CO
abundance
along
thereproduces
jet showsthatthe latterbearsfeatures
memoryof Etheearly
the jet kinematics, naturally accounting for their time variability. Signatures of internal shocks are detected as knots
the course of its propagation.
of thefieldtheshows
thatknots
theinteract
jet material
mainlyconsists of gas entrained
along the jet.Analysis
In the early timesof thevelocity
ejection process,young emittedwith the dense
circumstellar
through andhigh-velocity,dissociative away
shocks, whichstrongly
the CO at
gas abundance
the jet. As
from the circumstellarenvelope
envelope
accelerated
fromthe decrease
protostar
700 au inscale.
Astimea result, the overall jet
3proceeds, the knots propagate more smoothly through the envelope and dissociative shocks disappear after ⇠ 10 yr.
mass-loss rate appearsThehigher
thantheactualmass-ejection
rateby
a memory
factorof⇠the3.early dissociative phase in
distributionof COabundance
along
the jet shows that thelatterbears
course of its propagation.
Analysisof the velocity fieldshows thatthe comparison
jet material mainlywith
consistsof gasentrained
Conclusions. Numericalthemodeling
of
the
Cep
E
jet-driven
outflowandtheCO
observations have allowedfrom the circumstellar envelope and accelerated away from the protostar at 700 au scale. As a result, the overall jet
us to peer into the outflow
mechanism
withunprecedented
and to retrieve the history of the mass-loss
mass-lossformation
rate appears higher
than the actual
mass-ejection
rate by a factordetail⇠ 3.
Conclusions. Numerical modeling of the Cep E jet-driven outflow and comparison with the CO observations have allowed
events that have shaped
outflow.
us to thepeer into
the outflow formation mechanism with unprecedented detail and to retrieve the history of the mass-loss
events that have shaped the outflow.

Key words. stars: formation— ISM: jets and outflows — astrochemistry
Key words. stars: formation — ISM: jets and outflows — astrochemistry01nctionbased
on COIt andH2 .noticing they outflows.
ts are easily
identified.
is worth
daptativeuses
seven alonglevelstheofjet,refinement,
pand radiallymesh
as they
propagate
wings
innercells,
bowshocks,
the slower mate096⇥of1024in a sincecomputational
domain (5 ⇥ts with the faster material ejected at later times. 4. Gas acceleration
au, allowing a resolution as high as 12.2 au pers appear to drive the formation of complex strucreflective
boundary
for theeWethe used
outflowacavity
as can beseen in thecondition
bottomandmovinga freeknots
outflowboundary
forg.axis
2. Fasttend toaccumulateconditionattheborders.
bow, increasing
at meshthe tip.is
After
her
The thesizedensityof thelarge enoughe knots located at distance > 15000 au display
uterboundaries do not a↵ect the simulation. Thea typical size of 1000 au.
cted
on gasthedensity
left sideof the assimulation
pects theto decreasea result of box withalconditions
injet
Table
1.
xpansionin the indicatedcourse of the
propagation.

分⼦流の成⻑が進むにつれ、先端でこわされる。
≃ 900yrs経った
後ろの領域ではCOが再⽣される(グラフのわずかな平坦部)

1500yrsも経つとCOが再⽣された領域は
1e4 AU付近まで広がる(グラフの平坦部)

ooking in detail at the jet density field at e. g.
(second panel in Fig. 2), it appears that thedoes not decrease
along the narconditions:the monotonically
protostellar core
he density distribution of fast material along theanalyzedin Sectioncore,
5.2. we have adopted
on direction
describeis the
protostellar
500conditions
yr, a secondderived
outflow cavity
has now etformed.
alby Crimieral. (2010) from
utflow cavity has reached a size of ⇡ 15000 au andDtomodelingof the5000
dust
spectralenergy distribu00
up
a radius of aboutau (6at the distanceFig. 3. Cep E northern outflow lobe. Position-Velocity diagram
een
24µm
and
1300µm,using
theradiative
transmm), and the head of the outflow has reached a of the
CO J= 2–1 line emission along the jet main axis. Posi400
tions are in arcsec o↵set relative to the location of the driving⇥ 10 au (Ivezic(34 ). At&latertimes,1997).
the second
D2.8DUSTYElitzur
The temperaprotostar=Cep E-A. First contour and contour interval are 10%
ands
to reacha similar
radiusof ⇡ 5000
ed by
a brokenradialpower
law au.
T / r withion of Figure 2 reveals that a complex network of of the peak intensity. We have superimposed in yellow the beste range 50–300 K and = 0.4 in the range 7 K–
ense structures (n ⇠ 105 –106 cm 3 ) forms inside fitting solution (V Vlsr )/V0 = exp( 0 / ) where 0 = 690 au(Schutzertoet al. 2022).
Crimier’s
thecandensity
is ofassumed
w cavity verymodel,
early. One
note theprofile
presence
radius
70 first
au 1000
and yr.
toAsfollow
single radial
along
therjetin thecan beaseenin =eldistribution
at t= 1000 yr,n(r)=a filament
Cep E displays evidence of gas acceleration along the jetn0 ⇥has(r0formed/r)↵ . along
cated at R = 500 au, it is detected up to z = over a distance of 1000 au away from the protostar (Fig. 3).
er
to avoid density singularities in the limit r ! 0
nd appears as a thin, yellow, wiggling structure This e↵ect was reported and observationally characterizedmericalhave ofadopted
the byslightly
the jet. Wemodeling,also note thewepresencea ”shell”, or
Schutzer etal. 1.
(2022).
We showin the bottom
panel
Fig.
CO 2–1line emission
in theCep E-mm outflow as ob00
density
ch formedprofilein the dense protostellar envelope and of Fig. 4, theserved
synthetic
Position-Velocity
diagramof the (Lefloch et al. 2015).
with
the
PdBI
at
1
resolution
wly (⇠ 20 km s 1 ) as it propagates over 8000au CO gas along the main axis of the jet. Two kinematical
Four
main
velocity
components
are detected: a) the outflow
n0 the jet reached 40 ⇥ 103 au. This dense components arewhereasclearly
identified:i)alowvelocity
compo(1) cavity walls (black)↵ , the jet envelope of entrained gas to
at00 ) lowow)connects
8000 au (10from1velocities, in the range
nent,
between+0 and +10 km1s 1 up toemitting+ (r/r0 )[ 8; 3] km
and [ cavity
19; 14]kmii)
s a in the northern andwalls.
the source, associatedwiths the outflow
walls;
respectively;b) thejet, emitting at high veloci3 on the outflow morphology ap- high velocity southerncomponent,lobe,
that displaysa periodical
behavmericalresults=
109 cm, r0 = 100 au and ↵ = 1.9.
the mass
injectionand theod agreement with the NOEMA observations of ior, reflecting ties
in therange variability[ 135; 110]
kminternals 1 in the southern lobe (blue)
mulationtakes
thein rolein the fast material catches up with the slower
shocks, where
northernlobe(Fig. into
1). Asaccountcan be seen
Tableof2, gravity,and in the range [+40;+80] km s 1 in the northern lobe (red);withstratificationmaterial. Thec)jetthe
is detected
at terminala radial velocity
close tongth
andthethe source
radius of density
the outflow
cavity are cor- evidenced
southernbowshock
HH377, integrated in the1
Vj = 65 km s range
oduced;analysis.
this good Our
matchmodel
betweenincludes
observations
at z >[ 2000
frommier’sthe resulting
77, au64]kmthe
s 1source.
(green); d) the northern terminal bul-

まず、COが壊される

加速領域

nal
force as a source term, which reads:
ber, page 6 of 12

2 c20 r↵1 + (r/r0 ) )(2)

is the local sound speed. The inclusion of thisrm ensures hydrostatic equilibrium close to thelet NB integrated in the velocity range [+84,+97] km s 1 (magenta). First contour and contour interval are 20% and 10% of
the peak intensity in each component, respectively. The synthesized beam (100. 07 ⇥ 000. 87, HPBW) is shown in the bottom left
corner. The main axis of the northern and southern lobes of thejet are shown with black arrows. (Schutzer et al. 2022).

02

Mapping the distribution of OB stars and associations in Auriga
1¢11Alexis L. Quintana , Nicholas J. Wright and Robin D. Jeffries

1 Astrophysics Group, Keele University, Keele ST5 5BG, UK[astro-ph.SR] 17 Apr 2023

Accepted 2023 April 17. Received 2023 April 14; in original form 2023 February 15

ABSTRACTOB associations are important probes of recent star formation and Galactic structure. In this study, we focus on the Auriga
constellation, an important region of star formation due to its numerous young stars, star-forming regions and open clusters.
We show using Gaia data that its two previously documented OB associations, Aur OB1 and OB2, are too extended in propermotion and distance to be genuine associations, encouraging us to revisit the census of OB associations in Auriga with modern
techniques. We identify 5617 candidate OB stars across the region using photometry, astrometry and our SED fitting code,grouping these into 5 high-confidence OB associations using HDBSCAN. Three of these are replacements to the historical pairof associations - Aur OB2 is divided between a foreground and a background association - while the other two associations
are completely new. We connect these OB associations to the surrounding open clusters and star-forming regions, analyse themphysically and kinematically, constraining their ages through a combination of 3D kinematic traceback, the position of theirmembers in the HR diagram and their connection to clusters of known age. Four of these OB associations are expanding, withkinematic ages up to a few tens of Myr. Finally, we identify an age gradient in the region spanning several associations thatcoincides with the motion of the Perseus spiral arm over the last ⇠20 Myr across the field of view.
Key words: stars: kinematics and dynamics - stars: early-type - stars: massive - stars: distances - Galaxy: structure - open
clusters and associations: individual: Aur OB1, Aur OB2, Alicante 11, Alicante 12, COIN-Gaia_16, Gulliver 8, Kronberger 1,
NGC 1778, NGC 1893, NGC 1912, NGC 1960, Stock 8.

03áôböõú@7ìùCjoTo4û%ñó87ä%
Uüf†?43@<ñó<°\12i<éèêf|}~<ÄFë%

A. L. Quintana et al.

í9ì989îï<ñó87ä%

Figure 9. Galactic longitude as a function of SED-fitted distance for the 5 new OB associations in Auriga. The median error bars on distances are respectively⇠ 30 pc for associations 1 and 2, ⇠ 50 pc for association 3, ⇠ 70 pc for association 4 and ⇠ 160 pc for association 5.

tuUiGëò}@7H@<ñó=87\%

|}~<%

|}~<%

ÄF

ÄF

v%w%Lxy%z$.2{|ÅÇÉ@ÑÖÜTáà4âjT+'äLãväC%ÅÇÉRåEç

qrs

qrs

qrs

Figure 12. Median positions of the OB associations across the X-Y plane from the present time to 20 Myr in the past, shown relative to the Local Standard of
Rest. Uncertainties on their position from the traceback have been shown as a blur. The Perseus spiral arm model, including its thickness, is from Reid et al.
Figure 10. HR diagrams for the members of the new OB associations in Auriga. Isochrones have been shown from the rotating evolutionary models from(2019).
The
symbolcorresponds
toclarity.
the position of the Sun.
Ekström et al. (2012). Positions of some spectral
types have
beenSunindicatedon the top
horizontal axis for07

Planet formation via pebble accretion in externally photoevaporating discs
1¢
1
1
Lin Qiao, Gavin A. L. Coleman, Thomas J. Haworth【前提知識のメモ】Pebbles : 固体の流れで、Pebble⽣成フ

1 Astronomy Unit, School of Physics and Astronomy, Queen Mary University of London, London E1 4NS,ロントからr⽅向内側に降着して惑星を成⻑させる.
UK
外部輻射

で円盤外縁部があっというまに光蒸発してしまう場合,
Pebbles⽣成フロントが円盤外縁部に速く到達する. このため

stro-ph.EP] 27 Mar 2023

Accepted XXX. Received YYY; in original form ZZZPeble降着に必要な固体供給が⽌まり惑星成⻑のための質量置き場としての役割も終わる. 逆に, 円盤が外部輻射から遮蔽さABSTRACT

れていれば, 質量置き場としての役割維持.

We demonstrate that planet formation via pebble accretion is sensitive to external photoevaporation of the outer disc. In pebble
accretion, planets grow by accreting from a flux of solids (pebbles) that radially drift inwards from the pebble production front.
If external photoevaporation truncates the outer disc fast enough, it can shorten the time before the pebble production front
reaches the disc outer edge, cutting off the supply of pebble flux for accretion, hence limiting the pebble mass reservoir for planet
growth. Conversely, cloud shielding can protect the disc from strong external photoevaporation and preserve the pebble reservoir.
Because grain growth and drift can occur quickly, shielding even on a short time-scale (< 1 Myr) can have a non-linear impact on
the properties of planets growing by pebble accretion. For example a 10 3 " planetary seed at 25 au stays at 25 au with a lunar
mass if the disc is immediately irradiated by a 103 G0 field, but grows and migrates to be approximately Earth-like in both massand orbital radius if the disc is shielded for just 1 Myr. In NGC 2024, external photoevaporation is thought to happen to discs
that are < 0.5 Myr old, which coupled with the results here suggests that the exact planetary parameters can be very sensitive tothe star forming environment. Universal shielding for time-scales of at least ⇠ 1.5 Myr would be required to completely nullify
the environmental impact on planetary architectures.
Key words: planets and satellites: formation – protoplanetary discs – (stars:) circumstellar matter – stars: formation

08

External photoevaporation and pebble accretion∞±≤≥%$%¥%vµ%NO9j3ofLwLx¢%z$.£§%•[¶ßë®©ÜT£§R%™´¨≠ÆØ92RbcRÄT

•[¶ß∂∑∏π@f%∫ªº∞±≤≥%
Ωªºæø¨≠<¿¡¬√C%®©ƒ≈ë∆{Héèêë«¬√f7ì»…FGì9Tä

Figure 6. The final mass "final that the planetary embryos injected at 0init =25 AU reached as a function of shielding time Csh in discs evolved with FUV
tracks of different FUV, max values, indicated by different colors. There is anonlinear impact of shielding time on the planet’s final mass up to 1 Myr for
100 G0 .
FUV, max
Figure 4. Evolution of planetary embryo mass " ? against semi-major axis 0 in discs evolved with FUV tracks with FUV, max = 104 ⌧0 . In each subplot,
simulations with one specific shielding time Csh are included, and each colored curve represents the evolution trajectory of one planetary embryo in one discwith arrows indicating the direction of evolution. The initial planetary embryo core mass and semi-major axis (0init ) when injected is indicated by the circle.
Note that the plots only includes the simulations with 0init < 60 AU though the full 0init range simulated is 10 - 100 AU.

09

023

rXiv:2303.17784v1 [astro-ph.EP] 31 Mar 2023

gan Institute, Cornell University, Ithaca, NY 14853-6801
w Institute of Physics andEccentricity
Technology, Dolgoprudny,
Region,Planets
141700, Russia
Growth Moscow
of Massive
inside Cavities ofh Institute for Applied Mathematics,
Moscow, 125047,
Protoplanetary
Discs Russia
ment of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853-6801

M. M. Romanova1,2? , A. V. Koldoba3 , G. V. Ustyugova4 , D. Lai1,2 , R. V.
E. Lovelace1,2,5
1 Department of Astronomy, Cornell University, Ithaca, NY 14853-6801
2 Carl Sagan Institute, Cornell University, Ithaca, NY 14853-6801
3 Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, 141700, Russia
4 Keldysh Institute for Applied Mathematics, Moscow, 125047, Russia
5 Department of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853-6801

ABSTRACT
3 April 2023

We carry out hydrodynamical simulations to study the eccentricity growth of a 1ABSTRACT
30 Jupiter mass planet located inside the fixed cavity of a protoplanetary disc. The
carry outandhydrodynamical
simulations
to study thewith
eccentricity
growthofata 1-resonant locations,planet exchanges We
energyangularmomentumthedisc
30 Jupiter mass planet located inside the fixed cavity of a protoplanetary disc. The
planetgrows
exchangesdue
energyto
and Lindblad
angular momentum
with the disc at We
resonant
locations, several phases ofand its eccentricity
resonances.
observeand its eccentricity grows due to Lindblad resonances. We observe several phases of
eccentricity growthwheredi↵erent
eccentric
Lindbladeccentricity
growthwhere di↵erent
eccentric Lindblad
resonancesresonances
dominate from 1:3dominate from 1:3
up to 3:5. The maximum
valuesof eccentricity reachedin our simulations
are simulations
0.65upto
3:5.
The
maximum
valuesofeccentricity
reachedinourare
0.65過去の同様な計算に⽐べ、0.75. We calculate the eccentricity growth rate for di↵erent planet masses and discparametersand derive analyticalgrowthdependenciesrateon theseparameters.
We observethat masses and disc0.75.
We
calculatetheeccentricity
fordi↵erent
planetもっとも⼤きな離⼼率
the growth rate is proportional to both the planet’s mass and the characteristic discparameters
andderivedependencies
parameters.
mass for aanalyticalwide range of parameters.
In a separate on
set ofthesesimulations,
we derived the We observe thatになった(本⽂).
width of the 1:3 Lindblad resonance.
the growth rate is proportional to both the planet’s mass and the characteristic disc
Key words: accretion discs, hydrodynamics, planet-disc interactions, protoplanetary
mass for a wide rangeof parameters. In a separate set of simulations, we derived thediscs
width of the 1:3 Lindblad resonance.
Keywords: accretion discs, hydrodynamics,
planet-disc
protoplanetary
INTRODUCTION
A planet interacts
with the disc due tointeractions,the Lindblad andcorotation resonances (Goldreich & Tremaine 1979, 1980).
discs
Many massive exoplanets have high eccentricities. There
Lindblad resonances tend to increase the eccentricity of the1

is a wide distribution of eccentricities at di↵erent planet
masses and their distances from the star (see, e.g., Fig. 1
from Debras et al. 2021, which is based on the recent data

planet, while corotation resonances suppress the eccentricity growth (see also Goldreich & Sari 2003; Ogilvie & Lubow

10

Discussion
Sect. 6.1. キャビティのサイズ
Sect. 6.2. 先⾏研究との⽐較
Conclusions
1. ⻑時間にわたる離⼼率e成⻑は起こりうる.
2. 惑星のeは0.65-0.75と⼤きくなる傾向
3. 離⼼率成⻑は４段階を経る
4. 段階ごとの惑星質量の記述
5. 先⾏研究との⽐較
6. 粘性による成⻑時間を考えてもe成⻑は起こりうる7. 今後

Figure 3. Top 6 panels: waves forming in the inner disc in the Reference model at di↵erent times. Time is measured in periods ofrotation at r0 = 1. The color background shows the surface density. A small red dot shows the location of the planet, and small whitecircles show the locations of the spiral arms. The bottom panel shows the temporal evolution of the semi-major axis ap (red line) andeccentricity ep (blue line) of the planet’s orbit. The black vertical lines separate di↵erent phases of evolution, in which m = 1, 2, 3 or 4
spiral waves dominate.

11

Guyon55v1[astro-ph.EP]
27
Mar
2023
ph.EP] 27 Mar 2023

The

, Michael Bonnefoy , Faustine Cantalloube , H. Jens Hoeijmakers , Ulli Käufl , Markus Kasper ,Anne-Lise Maire6 , Mathilde Mâlin1 , Ralf Siebenmorgen19 , Ignas Snellen8 , and Gérard Zins19

Pictoris system: Setting constraints on the planet and the(Affiliations can be found after the references)?
disk structuresReceived
at mid-IR
wavelengths
with
NEAR
10/05/2022; accepted 08/03/2023

1,
2,
3
1
4
1
1
5
Nour Skaf, Anthony Boccaletti , Eric Pantin , Philippe Thebault , Quentin Kral , Camilla Danielski , Raphael

Galicher1 , Julien Milli6 , Anne-Marie Lagrange1 , ABSTRACT
Clément Baruteau7 , Matthew Kenworthy8 , Olivier Absil9 , Maud
18 +/- 2 Myrs 11
1012 , Nuria Huelamo13 , Philippe Delorme6 , Benjamin Charnay1 , Olivier
Langlois,
Johan
Olofsson,
Gael
ChauvinContext. Pictoris is a young nearby system hosting a well-resolved edge-on debris disk, along with at least two exoplanets. It o↵ers key
2,
14,
15,
16
6
17
18
19
19
opportunities
forcarrying
outdetailedstudiesoftheevolutionofyoungplanetarysystemsandtheirshaping
soon
after
the
end
of
the
planetary
Guyon, Michael Bonnefoy , Faustine Cantalloube , H. Jens Hoeijmakers , Ulli Käufl , Markus Kasper ,formation phase. Anne-Lise Maire6 , Mathilde Mâlin1 , Ralf Siebenmorgen19 , Ignas Snellen8 , and Gérard Zins19
Aims. We analyzed high-contrast coronagraphic images of this system, obtained in the mid-infrared, taking advantage of the NEAR experimentusing the VLT/VISIR instrument, which provides accessto adaptive
as wellasthe
phase
coronagraphy. The goal of our analysis is to investigate(Affiliations
canoptics,
be foundafter
references)both the detection of the planet Pictoris b and of the disk features at mid-IR wavelengths. In addition, by combining several epochs of observation,
Received
10/05/2022;
acceptedon
08/03/2023
we expect to constrain the position of the known clumps
and improve
our knowledge
the dynamics of the disk.
Methods. We observed the Pictoris system over two nights in December 2019 in the 10 12.5 µm coronagraphic filter. To evaluate the planet bflux contribution, we extracted the photometry at the expected position of the planet and compared it to the flux published in the literature as wellas the one we measured with SPHERE spectroscopy in the near-IR. ABSTRACT
In addition, we used previous data from T-ReCS and VISIR in the mid-IR,
updating the star’s distance, to study the evolution of the position of the southwest clump that was initially observed in the planetary disk back inContext. Pictoris is a young nearby system
hosting a well-resolved edge-on debris disk, along with at least two exoplanets. It o↵ers key
2003.
⼟星の環のような構造ではなく、フラックスの上限値から周惑星円盤のような構造が⽰唆される
opportunities
carryingout detailedof theable
evolutionof young onplanetarysystems
and their shaping
soon after
theoutend
the planetary
Results.
While for
we didnot detect
the planetstudiesb, we wereto put constraints
the presenceof circumplanetary
material,
rulingtheof
equivalentphase.
offormationa Saturn-likeplanetary ring around the planet. The disk presents several noticeable structures, including the known southwest clump. Using a
Aims. Weanalyzedhigh-contrast
coronagraphic
images weof thisin themid-infrared,
takingWe
advantageofthe
theclump
NEARorbits
experiment16-yearbaseline,sampledwith five epochsof observations,weresystem,
able to obtained
examine theevolutionof the clump.
found thatin
the VLT/VISIR
which
accesstoaddition
adaptive
optics,as wellas phasecoronagraphy.
The thegoalpresenceof our analysis
is toclump
investigate
a using
Keplerianmotion withinstrument,a semi-major
axis providesof 56.1+0.4
au.
In
to
the
known
clump,
theimagesclearly
showofasecond0.3
bothdetectionand of the
diskandfeaturesmid-IR wavelengths.
Inbe
addition,by combining
severalepochscorrelationsof observation,onthe thenortheastsideofofthe
theplanet
disk asPictoris
well as bpossibly
faintercloseratstructuresthat are yet toconfirmed.
Furthermore,
we foundwe expect
constrain
the position
the knownclumpsand improve
our knowledge
on thedynamics
the disk.
betweenthe toCOclumps detectedwithofALMA
and thenortheasternand southwesternclumpsin themid-IRof
images.
Methods. WeIf observed
the Pictoris
systemoverlocated
two nights
Decemberin the 10 amount12.5 µm
coronagraphic
thelimit
planet b
Conclusions.
the circumplanetary
material
wereat the inRocheradius,2019
the maximumof dustdeterminedfilter.
from Tothe evaluate
flux upper
flux contribution,
extracted
the photometry
positionthe planetand compared
it to theflux ofpublishedin the literaturearoundPictoris b we
wouldcorrespondto the massatofthe
anexpected
asteroid of
5 km inofdiameter.
Finally,
the Keplerianmotionthe southwesternclump asis wellas the one
we measured
with SPHERE
spectroscopy
in the presencenear-IR. of
In aaddition,from T-ReCS and VISIR in the mid-IR,
possibly
indicativeof a yet-to-bedetected planetor signals
vortex. we used previous dataクランプの軌道運動＠56AUを検出
updating the star’s distance, to study the evolution of the position of the southwest clump that was initially observed in the planetary disk back inKeywords. Exoplanets, Direct Imaging, High Angular Resolution
CO回転遷移輝線で観測されていたクランプとの対応も確認 122003.