SFN #364 1-14
担当：土井 聖明 (総研大D2)
1.

Insights on the Sun birth environment in the context of star-cluster formation in hub- lament systems

2.

Detection of ethanol, acetone, and propanal in TMC-1: New O-bearing complex organ- ics in cold sources

3.

Predicting Stellar Mass Accretion: An Optimized Echo State Network Approach in Time Series Modeling

4.

JOYS: JWST Observations of Young protoStars: Out ows and accretion in the high- mass star-forming region
IRAS23385+605

5.

Mother of Dragons: A Massive, quiescent core in the dragon cloud (IRDC G028.37+00.07)

6.

Surveying the Giant HII Regions of the Milky Way with SOFIA: V. DR7 and K3-50

7.

Three-dimensional, Time-dependent MHD Simulation of Disk-Magnetosphere-Stellar Wind Interaction in a T Tauri,Protoplanetary System

8.

JWST/NIRCam discovery of the rst Y+Y brown dwarf binary: WISE J033605.05­014350.4

9.

Planet formation in the PDS 70 system: Constraining the atmospheric chemistry of PDS 70b and c

10. Transition disc nature of post-AGB binary systems con rmed by mid-infrared interfer- ometry
11. The impact of dust evolution on the dead zone outer edge in magnetized protoplanetary disks
12. A novel survey for young substellar objects with the W-band lter VI: Spectroscopic census of sub-stellar members
and the IMF of σ Orionis cluster
13. Toward a 3D kinetic tomography of Taurus clouds: II. A new automated technique and its validation
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14. Modeling Two First Hydrostatic Core Candidates Barnard 1b-N and 1b-S

discovery of the first Y+Y brown dwarf binary: WISE J033605.05 014350.4
8. JWST/NIRCam
Per Calissendorﬀ, Matthew De Furio, Michael Meyer, Loïc Albert, Christian Aganze, Mohamad Ali-Dib,
Daniella C. Bardalez Gagliuﬃ, Frederique Baron, Charles A. Beichman, Adam J. Burgasser, Michael C. Cushing, Jacqueline Kelly Faherty, Clémence Fontanive, Christopher R. Gelino, John E. Gizis, Alexandra Z. Greenbaum, J. Davy Kirkpatrick, Sandy K. Leggett, Frantz Martinache, David Mary, Mamadou N’Diaye, Benjamin
J. S. Pope, Thomas L Roellig, Johannes Sahlmann, Anand Sivaramakrishnan, Daniel Peter Thorngren, Marie
Ygouf, Thomas Vandal F We report the discovery of the4 first brown dwarf binary system with a Y dwarf primary,

WISE J033605.05 014350.4, observed with NIRCam on JWST with the F150W and F480M filters. We employed
an empirical point spread function binary model to identify the companion, located at a projected separation of 84
milliarcseconds, position angle of 295 degrees, and with contrast of 2.8 and 1.8 magnitudes in F150W and F480M,
respectively. At a distance of 10 pc based on its Spitzer parallax, and assuming a random inclination distribution, thephysical separation is approximately 1 au. Evolutionary models predict for that an age of 1-5 Gyr, the companion
mass is about 4-12.5 Jupiter masses around the 7.5-20 Jupiter mass primary, corresponding to a companion-to-hostmass fraction of q = 0.61 ± 0.05. Under the assumption of a Keplerian orbit the period for this extreme binary isin the range of 5-9 years. The system joins a small but growing sample of ultracool dwarf binaries with eﬀective
temperatures of a few hundreds of Kelvin. Brown dwarf binaries lie at the nexus of importance for understanding theformation mechanisms of these elusive objects, as they allow us to investigate whether the companions formed as stars
or as planets in a disk around the primary.

JWSTでの褐色矮星連星の発見論文
Planet formation in the PDS 70 system: Constraining the atmospheric chemistry of
PDS 70b and c
・JWSTのNIRCAMを用いて褐色矮星を観測した
A. J. Cridland, S. Facchini, E. F. van Dishoeck, M. Benisty F Understanding the chemical link between proto・Y型
Y型の褐色矮星連星を初発見
planetary +disks
and planetary atmospheres is complicated by the fact that the popular targets in the study of disks
and planets are widely separated both in space and time. The 5 Myr PDS 70 systems oﬀers a unique opportunity
・連星間距離はおよそ1
to directly compare the chemistry ofau
a giant planet’s atmosphere to the chemistry of its natal disk. To that end, we
derive our current best physical and chemical model for the PDS 70 disk through forward modelling of the 12 CO,・連星の発見は褐色矮星の形成過程の解釈に重要(どう解釈できるのかあまり明瞭に書かれてなかったが…まあ一例ですし)18
C O, and C H emission radial profiles with the thermochemical code DALI and find a volatile C/O ratio above2

unity in the outer disk. Using what we know of the PDS 70 disk today, we analytically estimate the properties ofthe disk as it was 4 Myr in the past when we assume that the giant planets started their formation, and compute achemical model of the disk at that time. We compute the formation of PDS 70b and PDS 70c using the standard coreaccretion paradigm and account for the accretion of volatile and refractory sources of carbon and oxygen to estimate

イントロ
褐色矮星：水素燃焼していない星 (< 80 M̲jup)
スペクトル型：L型(~2000 K)、T型(~ 1000K)、Y型 (~500 K)
褐色矮星の形成過程
案：星と同じく重力崩壊
案：ガス惑星と同じく主星の周りの円盤内で形成
案：star forming aggregatesからの叩き出し(重力崩壊の途中で飛び出した?)→ 連星の研究から制限できるかも？
連星の特徴量(の質量依存性)
軌道半径a：log-normal分布、質量が大きいほどピークは大きい側に質量比q(=伴/主)：主星が大きいものほど質量比が大きい→ 褐色矮星の錬成の特徴量が星と同じ傾向を持っていれば、星と同様の過程で作られた？
T型矮星では軌道が小さく質量比qが大きいことが確認されてきた→ より軽い褐色矮星ではどう？

観測
対象天体：WISEの赤外観測により発見された12天体のF型褐色矮星
観測装置
WST NIRCAM
波長：F150W (1.5 um)、F480M (4.8 um)
温度が低いため赤外観測が必要。4.8 umの方が明るい
The Astrophysical Journal Letters, 947:L30 (6pp), 2023 April 20

Calissendorff et al.

Figure 1. JWST/NIRCam images showing the aligned and scaled images of the target W0336 in each observed ﬁlter. North is up and east is to the left in the images.

結果
The Astrophysical Journal Letters, 947:L30 (6pp), 2023 April 20

Calissendorff et al.

ピクセルサイズは63 mas、31 mas
近い時間に撮られたsingle天体の画像(3天体*5回)をもとにモデルを作成
The Astrophysical Journal Letters, 947:L30 (6pp), 2023 April 20

Calissendorff et al.

Table 1
Properties of the W0336 Binary System
Band
Separation [mas]Position angle [deg]Contrast [mag]W0336AB
W0336A
W0336B
Component
Teff [K]M [MJup] (1 Gyr)
M [MJup] (5 Gyr)
Physical separation [au]Orbital period [yr]Mass fraction q = MB/MA

F150W

F480M

+3.8
89.84.1
299.1 ± 3.4+0.19
2.820.11
21.97 ± 0.01
22.05 ± 0.01
+0.18
24.870.10+4.9
83.78.2+2.3
295.42.6+0.14
1.810.31
14.52 ± 0.01
+0.02
14.710.05+0.12
16.510.26

Primary
415 ± 20
8.5 ± 118 ± 2

Secondary
+15
32510
5±1
11.5 ± 1+0.05
0.970.09

7±20.61 ± 0.05

magnitude estimates and the Sonora evolutionary models

Figure 2. Images displaying the pipeline calibrated data of W0336 in the F480M band are in the left column, models are in the middle column, and theircorresponding residuals when the models have been subtracted from the data are in the right column. The top row shows a single model ﬁtted to the data, and the
middle row shows a binary double ePSF model. The bottom row depicts the same binary model as the middle row, but only showing the primary component from thatﬁt to better highlight the companion seen in the residuals after subtracting the primary component from the data. The units are in DN/s. The color scheme in theimages are scaled to a power law with an exponent of 0.5, and the color bar for the binary model residual image has been scaled to match the single model residual
image to better highlight the smaller residual and improved ﬁt.

Table 1 also gives the measured F150W and F480M Vegamagnitudes for the unresolved system and for the resolved
components, where the resolved magnitudes are calculated
from our contrast measurements of ﬂux ratio between thesystem, given in Table 1. The uncertainties in Teff have been
estimated from the range of MF150W values calculated by themodels for plausible ranges in gravity and metallicity (Table 9of Leggett et al. 2021).

Table 1
Properties of the W0336 Binary System

議論

Band
Separation [mas]Position angle [deg]Contrast [mag]W0336AB
W0336A
W0336B

F150W

F480M

+3.8
89.84.1
299.1 ± 3.4+0.19
2.820.11
21.97 ± 0.01
22.05 ± 0.01
+0.18
24.870.10+4.9
83.78.2+2.3
295.42.6+0.14
1.810.31
14.52 ± 0.01
+0.02
14.710.05+0.12
16.510.26

18 ± 2

Secondary
+15
32510
5±1
11.5 ± 1

Projected separation：0.89 au：非常に近い
年齢は1-5 Gyr程度か
年齢の見積りによって質量、軌道周期は不定性がある
Component
PrimaryT [K]415 ± 20
D燃焼を起こす質量(13M̲jup)よりも軽い可能性も
The Astrophysical Journal Letters, 947:L30(6pp),M [M] (12023
Gyr) April 20
8.5 ± 1eff

Jup

M [MJup] (5 Gyr)

Table 1
Physical separation [au]Properties of the W0336 Binary System
Band
Separation [mas]Position angle [deg]Contrast [mag]W0336AB
W0336A
W0336B
Component
Teff [K]M [MJup] (1 Gyr)
M [MJup] (5 Gyr)
Physical separation [au]Orbital period [yr]Mass fraction q = MB/MA

magnitude estimates and the

Orbital period [yr]Mass fraction q = MB/MA

F150W

F480M

Calissendorff et al.

+0.05
0.970.09
7±20.61 ± 0.05

+3.8
+4.9
89.883.7
4.1-8.2
magnitude estimates and+2.3 the Sonora evolutionary models
299.1 ± 3.4
295.4The-2.6 mass estimates range from 7.5 to(Marley et al. 2021).
+0.19
+0.14
2.821.81
20.0
M
for
the
primaryand 4.0 to 12.5 MJup for the
0.11
-0.31
Jup
secondary, and 14.52
the mass
21.97 ± 0.01
± 0.01ratio of the system is around
0.02the distribution found for low-mass
q = 0.6, at the low14.71
end +of22.05 ± 0.01
-0.05
binaries with masses 40+0.18+0.12 MJup inferred from Lyon/COND
24.8716.51
0.10
models (Fontanive et al.-0.26
2018). Interestingly, W0336B appears

to lie at or below the deuterium-burning limit of 13 MJup,
Primary
Secondarysometimes used as a +boundary
between brown dwarfs and15415 ± 20
10planets (Spiegel et 325
al. -2011).
If the system is 2 Gyr old or
8.5 ± 1younger, both components
5 ± 1 lie below this limit. In any case, thegrowing
18 ± 2companion joins a11.5± 1 list of cold brown dwarfs andisolated young brown dwarfs that may serve as a constraint on+0.05
0.97the minimum
0.09mass for opacity limited fragmentation.
Applying
7 ± 2the conversion factor of 1.16 between projected
and 0.61
physicalorbits from Dupuy & Liu (2011) for isotropic± 0.05
randomly distributed inclinations with the measured distance,+0.05
we ﬁnd the W0336 binary to be separated by 0.970.09 au.
Combining this with the mass range from the evolutionary
Sonoramodels,evolutionary
a tentative models
orbital period can be estimated for the

Figure 3. Color–magnitude diagram for W0336 in the NIRCam ﬁlters used inthis work. The open star corresponds to the unresolved system, and the black
ﬁlled points indicate the resolved components. Model sequences are shown for
effective temperatures, and surface gravities are indicated in the legend. All
models are for cloud-free solar metallicity atmospheres; however, the Sonora
models (Marley et al. 2021) are in chemical equilibrium, while the ATMO2020++ models (Phillips et al. 2020; Leggett et al. 2021) include disequilibrium
chemistry and also an adjusted pressure–temperature proﬁle. The masses along
the right axis are taken from the Sonora evolutionary models of Marley et al.
(2021), for log g = 4.5, and the temperatures are indicated along the sequences.

7.

Three-dimensional, Time-dependent MHD Simulation of Disk-Magnetosphere-Stellar
Wind Interaction in a T Tauri, Protoplanetary System
Ofer Cohen, Cecilia Garraﬀo, Jeremy Drake, Kristina Monsch, Igor Sokolov, Julian Alvarado-Gomez, Federico
Fraschetti F We present a three-dimensional, time-dependent, MHD simulation of the short-term interaction between

a protoplanetary disk and the stellar corona in a T Tauri system. The simulation includes the stellar magnetic field,
self-consistent coronal heating and stellar wind acceleration, and a disk rotating at sub-Keplerian velocity to induce
accretion. We find that initially, as the system relaxes from the assumed initial conditions, the inner part of the disk
winds around and moves inward and close to the star as expected. However, the self-consistent coronal heating andstellar wind acceleration build up the original state after some time, significantly pushing the disk out beyond 10R? .
After this initial relaxation period, we do not find clear evidence of a strong, steady accretion flow funneled along
coronal field lines, but only weak, sporadic accretion. We produce synthetic coronal X-ray line emission light curves
which show flare-like increases that are not correlated with accretion events nor with heating events. These variationsin the line emission flux are the result of compression and expansion due to disk-corona pressure variations. Verticaldisk evaporation evolves above and below the disk. However, the disk - stellar wind boundary stays quite stable, andany disk material that reaches the stellar wind region is advected out by the stellar wind.

T Tauri 星周りの円盤と中心星(コロナ)の相互作用を、3次元MHD計算から解明する
JWST/NIRCam discovery of the first Y+Y brown dwarf binary: WISE J033605.05 014350.4
・恒星磁場、コロナ加熱、恒星風による降着、サブケプラー回転による降着を入れた計算を行った
Per Calissendorﬀ, Matthew De Furio, Michael Meyer, Loïc Albert, Christian Aganze, Mohamad Ali-Dib,
DaniellaC.
Bardalez
Gagliuﬃ,
FrederiqueBaron,CharlesA.
Beichman,Adam
J.
Burgasser,
MichaelC.
Cush・計算初期には円盤内側は中心星に近づく
ing, Jacqueline Kelly Faherty, Clémence Fontanive, Christopher R. Gelino, John E. Gizis, Alexandra Z. Green・しばらくするとコロナ加熱と恒星風により円盤内縁が10R̲starまで後退
・その後は弱い散発的な降着が起きる
4

イントロ
円盤と惑星の相互作用は、円盤進化にも恒星進化にも重要・質量輸送、恒星のスピンアップ、円盤の進化
古典的理解
・円盤内側は恒星磁気圏によりtruncationされる・円盤物質は構成磁場に沿って長期的に、定常的に中心星に降着
降着の観測
・数日オーダーの変動
・降着量は 10^{-11} ~ 10^{-7} M̲sun ぐらいの不定性
近年の解釈・短期的に、間欠的に降着が起きている
・恒星の磁場が、コロナを加熱したり、恒星風を加速し、定常的なものではない→ 磁場と円盤の相互作用ではなく、コロナと円盤の相互作用を考える必要がある

計算設定
円盤、恒星磁場、コロナ加熱、恒星風の加速の影響を考慮した3D計算
・恒星、磁場、恒星風やコロナ(円盤以外)のモデル：Alfven
Wave
Solar
Model
The Astrophysical Journal, 949:54 (15pp), 2023 June 1
・3Dの非理想MHD方程式 + 運動量方程式(wind加速) + エネルギー方程式(コロナ加熱)
・恒星モデル：太陽質量、太陽半径、自転周期90日(ほぼ回転していない)
100 Gのダイポール磁場、円盤と45度の傾き

Cohen et al.

・円盤モデル・鉛直方向には静水圧平衡・ややサブケプラー円盤にして降着を起こす

Figure 1. Top: the grid structure in the simulation displayed on a sphere of r = 1.1Rå, and on the z = 0, and x = 0 (top left only) slices. The full domain is shown on結果(・最初に25時間は初期条件から定常状態への遷移)
・30 hぐらいでコロナにより円盤内縁半径が10 R̲starぐらいまで広がる
・計算時間中に、磁場に沿った定常的な降着は見られなかった。
弱い、散発的な(sporadic)降着が見られた。
The Astrophysical Journal, 949:54 (15pp), 2023 June 1

Cohen et al.

Figure 2. The three-dimensional structure of the disk–corona inner region as seen from 30° above the equator (similar to Figure 1, left panels). The left panel shows awhite isosurface of n = 1010 cm−3, which represents the higher-density region of the disk. The two initial gaps in the isosurface are due to the tilt of the stellar dipole
ﬁeld. The blue lines mark selected magnetic ﬁeld lines that cover the displayed region. The middle panel shows the same isosurface with red-colored velocity
streamlines. In the right panel, we show the equatorial plane colored with contours of the temperature, where blue regions mark the cold disk material and red regions
mark the hot corona. These are sample snapshots for t = 0 (top panels) and t = 108 hr (bottom panels). An animation of this ﬁgure is available. The animation starts at
t = 0 and ends at t = 108:30 hr in 30 minute steps. The real-time duration of the animation is 37 s, and it covers the full 108.5 hr of the simulation.
(An animation of this ﬁgure is available.)pressure of the disk, is not circular, but it has two “wing” gaps
due to the nonsymmetric tilted stellar dipole ﬁeld.
The global structure view shows a number of features. First,
the coronal magnetic ﬁeld, which is initially zero in the disk, isbeing warped around by the rotational motion of the disk. Afterone Keplerian rotation, the ﬁeld in the disk is almost purely
azimuthal, and the radial stellar wind ﬁeld is affected by thisbeing pushed away. We discuss this pattern and the overall disk
accretion in Section 4.2.
3.2. Radial Pressure Balance between the Disk and the Stellar
CoronaThe Astrophysical Journal, 949:54 (15pp), 2023 June 1

Cohen et al.

Figure 3. Temporal evolution of the radial distribution of the different pressure components as a function of distance from the star. The pressure components arethermal, dynamic, magnetic, and total. Plots show the radial distribution along extracted lines in the equatorial plane at four longitudes: 0 (ﬁrst column), 90 (second
column), 180 (third column), and 270 (fourth column) degrees. These are sample snapshots for t = 0 (top panels) and t = 108 hr (bottom panels). An animation of thisﬁgure is available. The animation starts at t = 0 and ends at t = 108:30 hr in 30 minute steps. The real-time duration of the animation is 36 s, and it covers the full
108.5 hr of the simulation.
(An animation of this ﬁgure is available.)

3.3. Vertical Evolution of the Disk
Figure 4 shows the evolution of the disk’s vertical structure
at t = hr. The complete evolution of the simulation for thisadvected outwards by the stellar wind. The total pressure isdominated by the dynamic (Keplerian) pressure in the disk, andby the dynamic and magnetic pressure in the stellar wind (the結果

The Astrophysical Journal, 949:54 (15pp), 2023 June 1

Cohen et・ライン強度は変化したが、ラインの増光と降着、
加熱イベントの間に相関は見られず、円盤とコロナの圧力の相互作用によるコロナの圧縮によるものである。
・円盤の上下で円盤風が発生。境界は安定しており、円盤風に入った物質は飛ばされる。

Figure 5. Top panel: integrated ﬂuxes of the synthetic EUV/X-ray images produced by the simulation as a function of time. The ﬂuxes are normalized to th
individual initial ﬂuxes at t = 0 hr. Dashed lines mark the temporal peak increase in the ﬂuxes at t = 17, 50, and 78 hr. The bottom three panels show the synthe
171 Å EUV and XRT images (two left columns, respectively) during the time of the peak ﬂux increase. The left panel shows an isosurface similar to that in Figure
The second column shows an isosurface of vr = −30 km s−1, which represents an infalling material region, colored with contours of the temperature. It shows som
but very little cold material accreting. The left two columns show the three-dimensional structure close to the star during the time of the EUV/X-ray ﬂux increase afrom the same viewing angle as the LOS of the images in the two right columns.

11.

The impact of dust evolution on the dead zone outer edge in magnetized protoplanetary
disks

Timmy N. Delage, Matías Gárate, Satoshi Okuzumi, Chao-Chin Yang, Paola Pinilla, Mario Flock, SebastianMarkus Stammler, Tilman Birnstiel F [Abridged] Aims. We provide an important step toward a better under-

standing of the magnetorotational instability (MRI)-dust coevolution in protoplanetary disks by presenting a proof
of concept that dust evolution ultimately plays a crucial role in the MRI activity. Methods. First, we study how afixed power-law dust size distribution with varying parameters impacts the MRI activity, especially the steady-state
MRI-driven accretion, by employing and improving our previous 1+1D MRI-driven turbulence model. Second, we
relax the steady-state accretion assumption in this disk accretion model, and partially couple it to a dust evolution
model in order to investigate how the evolution of dust (dynamics and grain growth processes combined) and MRIdriven accretion are intertwined on million-year timescales. Results. Dust coagulation and settling lead to a higher
gas ionization degree in the protoplanetary disk, resulting in stronger MRI-driven turbulence as well as a more compact dead zone. On the other hand, fragmentation has an opposite eﬀect because it replenishes the disk in small
dust particles. Since the dust content of the disk decreases over million years of evolution due to radial drift, theMRI-driven turbulence overall becomes stronger and the dead zone more compact until the disk dust-gas mixture
eventually behaves as a grain-free plasma. Furthermore, our results show that dust evolution alone does not lead to
a complete reactivation of the dead zone. Conclusions. The MRI activity evolution (hence the temporal evolution of
the MRI-induced ↵-parameter) is controlled by dust evolution and occurs on a timescale of local dust growth, as longas there is enough dust particles in the disk to dominate the recombination process for the ionization chemistry. Once
it is no longer the case, it is expected to be controlled by gas evolution and occurs on a viscous evolution timescale.

円盤ダスト成長とMRI乱流のシミュレーション論文
A novel survey for young substellar objects with the W-band filter VI: Spectroscopic
census of sub-stellar members and the IMF of Orionis cluster
・円盤乱流は円盤進化やダスト成長をコントロール
Belinda Damian, Jessy Jose, Beth Biller, Gregory J. Herczeg, Loic Albert, Katelyn Allers, Zhoujian Zhang,Michael C. Liu, Sophie Dubber,
KT Paul,Wen-Ping Chen, Bhavana Lalchand, Tanvi Sharma, Yumiko Oasa F・Magnetorotational
Instability(MRI)は強い乱流を引き起こす機構の一つ
Low-mass stars and sub-stellar objects are essential in tracing the initial mass function (IMF). We study the nearby
young
Orionis cluster (d⇠408 pc; age⇠1.8 Myr) using deep NIR photometric data in zoneと呼ばれる低乱流領域を作る
J, W and H-bands from・MRIはダストの量やサイズによって安定化することがあり、dead
WIRCam on the Canada-France-Hawaii Telescope. We use the water absorption feature to photometrically select・ダストの成長のMRI
deadtheirzoneの関係を調べた
the brown dwarfs and confirm
nature spectroscopically with the IRTF-SpeX. Additionally we select candidate
low-mass stars for spectroscopy and analyze their membership and that of literature sources using astrometry from
（おそらく次のシリーズ論文(?)でよりダスト成長⇆MRI⇆円盤進化のコンシステントな計算をやる）
Gaia DR3. We obtain the near-IR spectra for 28very low-mass stars and brown dwarfs andestimate their spectral

イントロ
原始惑星系円盤においてMRI乱流は重要
・円盤粘性進化を起こす・dead zone outer (inner) boundaryはダストリングを作る？
MRIはダストの量によって安定化する・MRIは磁場と円盤が引き起こす不安定性 ← 円盤が磁場と結合(電離)していないといけない・ダストは円盤電離度を決定：ダスト表面に電子やイオンがぶつかって中性に・特に円盤内側で安定化し、dead zoneと呼ばれる低乱流状態を作りうる・dead zone境界ではガスやダストが溜まりリングを作ることも考えられる

https://www.physics.unlv.edu/~rgmartin/Dead̲Zones.html

手法
目標：ダスト移流・成長とMRI (dead zone)を整合的に解く
・第一原理的にMRIを解くのは計算コストが大きい(短時間の計算)
・ダスト移流成長は長時間の発展→ うまく(?)MRIをモデル化して両方の効果を取り入れた計算をする
T. N. Delage et al.: The impact of dust evolution on the dead zone outer edge in magnetized protoplanetary disks
Framework:- Viscously driven accretion- MRI and Hydro turbulence onlyM,* L *

ρdust, tot

Disk dust

t, t

n dus
Nonthermal
ionization sources

,σd

ot

A

,𝛇 R

Ionization chemistryn,i

σdust, rep , mdust, rep- Nonideal MHD effects =>Ohmic & Ambipolar diffusion- Active MRI criterion =>Λ > 1 & β > βmin(Am)

B, vA
β

- Stellar X-rays- Cosmic rays
- Radionuclides

R

ep
t, r

,T
n gas

Disk
magnetisation

us

M*

,𝛇 C
𝛇 XR

,ad

ep
t, r

ρgas, T

us

,T
n gas

- Input profile by the user

Σgas

Model inputs:- Stellar properties- Gas properties- Dust properties- Hydro turbulent parameter αhydroLXR

Σ gas, ρ gas
Disk gas

B is either:- “Optimal” for the MRI
activity (maximizes theaccretion rate in the
MRI-active layer)

Host star

n

e,n
ch

ar
ge
d

du

st

Nonideal MHD
)

Am
(
n
Λ, β mi2D MRI-induced α
assuming a value for αhydro⇒Semi-analyticalmodel that captures
the charge state of thedisk dust-gas mixture

Effective MRI-induced α

Fig. 1. Flowchart of the MRI-driven disk accretion model presented in Delage et al. (2022). This model captures the essence of the MRI-driven
turbulence in a 1+1D framework, accounting for the following: stellar properties (gray symbols), disk gas properties (blue symbols), disk dust
properties (red symbols), nonthermal ionization sources (yellow symbols), ionization chemistry modeling the gas ionization degree (green symbols), disk magnetisation properties (powder blue symbols), and nonideal MHD calculations (dark pink symbols). The main output of the model isan e↵ective radial profile for the MRI-induced viscosity parameter, ↵¯ (Eq. (1)). In this paper, we improve the dust phase modeling with a dust size
distribution, either by assuming a fixed power-law distribution with di↵erent properties or the outputs from dust evolution obtained with DustPy(see Table 1 and text in Sect. 2.3 for further explanations).

結果
A&A proofs: manuscript no. aa_original_tdelage

結果1：ダスト移流成長を考慮しない場合の定常解

左：最大ダストサイズを変えた場合
Appdenxixには最小ダストサ
イズを変えた場合や分布のべきを変えた場合の計算もFig. 2. Impact on the steady-state MRI-driven accretion when varying the maximum grain size, adist,Max , of the fixed power-law dust size distribution(Model I). Going from solid light-colored to dark-colored lines, adist,Max spans the range from 1 µm to 1 cm. The panels show the steady-stateradial profiles of several key quantities (see also Delage et al. 2022, for their definition), for the model parameters M? = 1 M , L? = 2 L ,Mdisk = 0.05 M? , fdg,tot = 10 2 , ↵hydro = 10 4 , amin = 0.1 µm, and pdist,Exp = 3.5. Panel a: pressure-weighted vertically integrated turbulent
parameter, ↵.
¯ Panel b: gas surface density, ⌃gas . Panel c: mid-plane total ionization rate, ⇣. Panel d: mid-plane optimal r.m.s. magnetic fieldstrength, B. Panel e: (constant) gas accretion rate, Ṁacc,gas . Panel f : mid-plane radial dead zone outer edge location, RDZ . For comparison, thedashed gray and black lines in Panel a display the steady-state quantity ↵¯ obtained assuming the limiting case of a mono-disperse population ofdust with size amono = 0.1 µm and amono = 1 cm (grain-free case), respectively.

結論：小さいダストが多いほど(表面積が大きいほど)deadzoneは大きくなる

結果
A&A proofs: manuscript no. aa_original_tdelage
結果2：ダスト移流成長を考慮した場合の時間発展(ガスは止めている)

Dead zone outer boundary
は10 - 50 au程度
ダスト成長タイムスケールでdead zoneも進化
気層での再結合も起きるので、内側ではdead zoneは残る
Fig. 4. Impact of dust evolution on the MRI-driven turbulence, for Model IV. The panels show the temporal evolution of the same quantities as inFig. 2, except for the gas accretion rate. Also, the gas surface density is now fixed to the displayed input profile in Panel b. We emphasize that thesequantities do not describe steady-state MRI-driven accretion (unlike Fig. 2), since they are re-calculated at each dust evolution snapshot, throughpartial coupling between the 1D radial dust evolution model employed and our MRI-driven turbulence model. On this note, the corresponding
temporal evolution of the five dust quantities used to perform such a coupling are shown in Fig. 5. Here we note that, in Panel f, the dead zone
outer edge coincides at t = 0 yr, t = 100 yrs and t = 1000 yrs.

Insights
on
the
Sun
birth
environment
inthecontextofstar-cluster
formationinhub1. filament systems
Doris Arzoumanian, Sota Arakawa, Masato I. N. Kobayashi, Kazunari Iwasaki, Kohei Fukada, Shoji Mori,
Yutaka Hirai, Masanobu Kunitomo, M. S. Nanda Kumar, Eiichiro Kokubo F Cylindrical molecular filaments

are observed to be the main sites of Sun-like star formation, while massive stars form in dense hubs, at the junctionof multiple filaments. The role of hub-filament configurations has not been discussed yet in relation to the birthenvironment of the solar system and to infer the origin of isotopic ratios of Short-Lived Radionuclides (SLR, such as
26Al) of Calcium-Aluminum-rich Inclusions (CAIs) observed in meteorites. In this work, we present simple analyticalestimates of the impact of stellar feedback on the young solar system forming along a filament of a hub-filament
system. We find that the host filament can shield the young solar system from the stellar feedback, both during theformation and evolution of stars (stellar outflow, wind, and radiation) and at the end of their life (supernovae). We
show that the young solar system formed along a dense filament can be enriched with supernova ejecta (e.g., 26 Al)
during the formation timescale of CAIs. We also propose that the streamers recently observed around protostars
may be channeling the SLR-rich material onto the young solar system. We conclude that considering hub-filamentconfigurations as the birth environment of the Sun is important when deriving theoretical models explaining theobserved properties of the solar system.

Detection of ethanol, acetone, and propanal in TMC-1: New O-bearing complex organics in cold sources

M. Agundez, J. C. Loison, K. M. Hickson, V. Wakelam, R. Fuentetaja, C. Cabezas, N. Marcelino, B. Tercero,P. de Vicente, J. Cernicharo F We present the detection of ethanol (C2H5OH), acetone (CH3COCH3), and propanal(C2H5CHO) toward the cyanopolyyne peak of TMC-1. These three O-bearing complex organic molecules are known
to be present in warm interstellar clouds, but had never been observed in a starless core. The addition of these three
new pieces to the puzzle of complex organic molecules in cold interstellar clouds stresses the rich chemical diversityof cold dense cores in stages prior to the onset of star formation. The detections of ethanol, acetone, and propanal

2.

Detection of ethanol, acetone, and propanal in TMC-1: New O-bearing complex organics in cold sources

M. Agundez, J. C. Loison, K. M. Hickson, V. Wakelam, R. Fuentetaja, C. Cabezas, N. Marcelino, B. Tercero,P. de Vicente, J. Cernicharo F We present the detection of ethanol (C2H5OH), acetone (CH3COCH3), and propanal(C2H5CHO) toward the cyanopolyyne peak of TMC-1. These three O-bearing complex organic molecules are known
to be present in warm interstellar clouds, but had never been observed in a starless core. The addition of these three
new pieces to the puzzle of complex organic molecules in cold interstellar clouds stresses the rich chemical diversityof cold dense cores in stages prior to the onset of star formation. The detections of ethanol, acetone, and propanal
were made in the framework of QUIJOTE, a deep line survey of TMC-1 in the Q band that is being carried out with
the Yebes 40m telescope. We derive column densities of (1.1 +/- 0.3)e12 cm-2 for C2H5OH, (1.4 +/- 0.6)e11 cm-2
for CH3COCH3, and (1.9 +/- 0.7)e11 cm-2 for C2H5CHO. The formation of these three O-bearing complex organic
molecules is investigated with the aid of a detailed chemical model which includes gas and ice chemistry. The calculated
abundances at a time around 2e5 yr are in reasonable agreement with the values derived from the observations. The
formation mechanisms of these molecules in our chemical model are as follows. Ethanol is formed on grains by addi2
tion of atomic carbon on methanol followed by hydrogenation and non-thermal desorption. Acetone and propanal are
produced by the gas-phase reaction between atomic oxygen and two diﬀerent isomers of the C3H7 radical, where thelatter follows from the hydrogenation of C3 on grains followed by non-thermal desorption. A gas-phase route involving
the formation of (CH3)2COH+ through several ion-neutral reactions followed by its dissociative recombination withelectrons do also contribute to the formation of acetone.

Predicting Stellar Mass Accretion: An Optimized Echo State Network Approach inTime Series Modeling

Gianfranco Bino, Shantanu Basu, Ramit Dey, Sayantan Auddy, Lyle Muller, Eduard I. Vorobyov F Modelingthe dynamics of the formation and evolution of protostellar disks as well as the history of stellar mass accretion
typically involve the numerical solution of complex systems of coupled diﬀerential equations. The resulting massaccretion history of protostars is known to be highly episodic due to recurrent instabilities and also exhibits shortPredicting
Stellar
Mass
Accretion:
An
Optimized
Echo
State
Network
Approachin
3. Time Series Modeling

Gianfranco Bino, Shantanu Basu, Ramit Dey, Sayantan Auddy, Lyle Muller, Eduard I. Vorobyov F Modelingthe dynamics of the formation and evolution of protostellar disks as well as the history of stellar mass accretion
typically involve the numerical solution of complex systems of coupled diﬀerential equations. The resulting massaccretion history of protostars is known to be highly episodic due to recurrent instabilities and also exhibits shorttimescale flickering. By leveraging the strong predictive abilities of neural networks, we extract some of the critical
temporal dynamics experienced during the mass accretion including periods of instability. Particularly, we utilize anovel form of the Echo-State Neural Network (ESN), which has been shown to eﬃciently deal with data having inherent
nonlinearity. We introduce the use of Optimized-ESN (Opt-ESN) to make model-independent time series forecasting ofmass accretion rate in the evolution of protostellar disks. We apply the network to multiple hydrodynamic simulations
with diﬀerent initial conditions and exhibiting a variety of temporal dynamics to demonstrate the predictability of
the Opt-ESN model. The model is trained on simulation data of ⇠ 1 2 Myr, and achieves predictions with a low
normalized mean square error (⇠ 10 5 to 10 3 ) for forecasts ranging between 100 and 3800 yr. This result shows thepromise of the application of machine learning based models to time-domain astronomy.

JOYS: JWST Observations of Young protoStars: Outflows and accretion in the highmass star-forming region IRAS23385+605
H. Beuther, E. F. van Dishoeck, L. Tychoniec, C. Gieser, P. J. Kavanagh, G. Perotti, M. L. van Gelder, P.
Klaassen, A. Caratti o Garatti, L. Francis, W. R. M. Rocha, K. Slavicinska, T. Ray, K. Justtanont, H. Linnartz,
C. Weakens, L. Colina, T. Greve, M. Guedel, T. Henning, P. O. Lagage, B. Vandenbussche, G. Oestlin, G.
Wright F Aims: The JWST program JOYS (JWST Observations of Young protoStars) aims at characterizing thephysical and chemical properties of young high- and low-mass star-forming regions, in particular the unique midinfrared diagnostics of the warmer gas and solid-state components. We present early results from the high-mass starformation region IRAS23385+6053. Methods: The JOYS program uses the MIRI MRS with its IFU to investigate

JOYS: JWST Observations of Young protoStars: Outflows and accretion in the high4. mass star-forming region IRAS23385+605
H. Beuther, E. F. van Dishoeck, L. Tychoniec, C. Gieser, P. J. Kavanagh, G. Perotti, M. L. van Gelder, P.
Klaassen, A. Caratti o Garatti, L. Francis, W. R. M. Rocha, K. Slavicinska, T. Ray, K. Justtanont, H. Linnartz,
C. Weakens, L. Colina, T. Greve, M. Guedel, T. Henning, P. O. Lagage, B. Vandenbussche, G. Oestlin, G.
Wright F Aims: The JWST program JOYS (JWST Observations of Young protoStars) aims at characterizing thephysical and chemical properties of young high- and low-mass star-forming regions, in particular the unique midinfrared diagnostics of the warmer gas and solid-state components. We present early results from the high-mass starformation region IRAS23385+6053. Methods: The JOYS program uses the MIRI MRS with its IFU to investigate
a sample of high- and low-mass star-forming protostellar systems. Results: The 5 to 28mum MIRI spectrum of
IRAS23385+6053 shows a plethora of features. While the general spectrum is typical for an embedded protostar, we
see many atomic and molecular gas lines boosted by the higher spectral resolution and sensitivity compared to previous
space missions. Furthermore, ice and dust absorption features are also present. Here, we focus on the continuum
emission, outflow tracers like the H2, [FeII] and [NeII] lines as well as the potential accretion tracer Humphreys alphaHI(7–6). The short-wavelength MIRI data resolve two continuum sources A and B, where mid-infrared source A is
associated with the main mm continuum peak. The combination of mid-infrared and mm data reveals a young clusterin its making. Combining the mid-infrared outflow tracer H2, [FeII] and [NeII] with mm SiO data shows a complex
interplay of at least three molecular outflows driven by protostars in the forming cluster. Furthermore, the Humphreysalpha line is detected at a 3-4sigma level towards the mid-infrared sources A and B. Following Rigliaco et al. (2015),
one can roughly estimate accretion luminosities and corresponding accretion rates between 2.6x10 6 and 0.9x10 4
Msun/yr. This is discussed in the context of the observed outflow rates. Conclusions: The analysis of the MIRI MRS
observations for this young high-mass star-forming region reveals connected outflow and accretion signatures.

Mother of Dragons: A Massive, quiescent core in the dragon cloud (IRDC G028.37+00.07)
A. T. Barnes, J. Liu, Q. Zhang, J. C. Tan, F. Bigiel, P. Caselli, G. Cosentino, F. Fontani, J. D. Henshaw, I.
Jiménez-Serra, D-S. Kalb, C. Y. Law, S. N. Longmore, R. J. Parker, J. E. Pineda, A. Sánchez-Monge, W. Lim,K. Wang F Context: Core accretion models of massive star formation require the existence of massive, starless cores

of Dragons: A Massive, quiescent core in the dragon cloud (IRDC G028.37+00.07)
5. MotherA. T. Barnes, J. Liu, Q. Zhang, J. C. Tan, F. Bigiel, P. Caselli, G. Cosentino, F. Fontani, J. D. Henshaw, I.
Jiménez-Serra, D-S. Kalb, C. Y. Law, S. N. Longmore, R. J. Parker, J. E. Pineda, A. Sánchez-Monge, W. Lim,K. Wang F Context: Core accretion models of massive star formation require the existence of massive, starless coreswithin molecular clouds. Yet, only a small number of candidates for such truly massive, monolithic cores are currently
known. Aims: Here we analyse a massive core in the well-studied infrared-dark cloud (IRDC) called the ’dragon
cloud’ (also known as G028.37+00.07 or ’Cloud C’). This core (C2c1) sits at the end of a chain of a roughly equally
spaced actively star-forming cores near the centre of the IRDC.
Methods: We present new high-angular resolution 1
3
mm ALMA dust continuum and molecular line observations of the massive core. Results: The high-angular resolution
observations show that this region fragments into two cores C2c1a and C2c1b, which retain significant backgroundsubtracted masses of 23 Msun and 2 Msun (31 Msun and 6 Msun without background subtraction), respectively. The
cores do not appear to fragment further on the scales of our highest angular resolution images (0.200 arcsec, 0.005 pc
1000 AU). We find that these cores are very dense (nH2 > 106 cm 3 ) and have only trans-sonic non-thermal motions(Ms ⇠ 1). Together the mass, density and internal motions imply a virial parameter of < 1, which suggests the coresare gravitationally unstable, unless supported by strong magnetic fields with strengths of ⇠ 1 - 10 mG. From COline observations, we find that there is tentative evidence for a weak molecular outflow towards the lower-mass core,and yet the more massive core remains devoid of any star formation indicators. Conclusions: We present evidence forthe existence of a massive, pre-stellar core, which has implications for theories of massive star formation. This source
warrants follow-up higher-angular-resolution observations to further assess its monolithic and pre-stellar nature.

Surveying the Giant HII Regions of the Milky Way with SOFIA: V. DR7 and K3-50

James M. De Buizer, Wanggi Lim, James T. Radomski, Mengyao Liu F We present our fifth set of results fromour mid-infrared imaging survey of Milky Way Giant HII (GHII) regions with our detailed analysis of DR7 and K3-50.
We obtained 20/25 and 37um imaging maps of both regions using the FORCAST instrument on the Stratospheric
Observatory For Infrared Astronomy (SOFIA). We investigate the multi-scale properties of DR7 and K3-50 using ourdata in conjunction with previous multi-wavelength observations. Near to far-infrared spectral energy distributions ofSurveying
the
Giant
HII
Regions
of
the
Milky
Way
with
SOFIA:
V.
DR7
and
K3-50
6.

James M. De Buizer, Wanggi Lim, James T. Radomski, Mengyao Liu F We present our fifth set of results fromour mid-infrared imaging survey of Milky Way Giant HII (GHII) regions with our detailed analysis of DR7 and K3-50.
We obtained 20/25 and 37um imaging maps of both regions using the FORCAST instrument on the Stratospheric
Observatory For Infrared Astronomy (SOFIA). We investigate the multi-scale properties of DR7 and K3-50 using ourdata in conjunction with previous multi-wavelength observations. Near to far-infrared spectral energy distributions ofindividual compact infrared sources were constructed and fitted with massive young stellar object (MYSO) models.
We find eight out of the ten (80%) compact sources in K3-50 and three out of the four (75%) sources in DR7 arelikely to be MYSOs. We derived luminosity-to-mass ratios of the extended radio sub-regions of DR7 and K3-50 toestimate their relative ages. The large spread in evolutionary state for the sub-regions in K3-50 likely indicates that thestar-forming complex has undergone multiple star-forming events separated more widely in time, whereas the smaller
spread in DR7 likely indicates the star formation sub-regions are more co-eval. DR7 and K3-50 have Lyman continuum
photon rates just above the formal threshold criterion for being categorized as a GHII region (1050 photons/s) but
with large enough errors that this classification is uncertain. By measuring other observational characteristics in theinfrared, we find that K3-50 has properties more akin to previous bona fide GHII regions we have studied, whereas
DR7 has values more like those of the non-GHII regions we have previously studied.

Three-dimensional, Time-dependent MHD Simulation of Disk-Magnetosphere-Stellar
Wind Interaction in a T Tauri, Protoplanetary System
Ofer Cohen, Cecilia Garraﬀo, Jeremy Drake, Kristina Monsch, Igor Sokolov, Julian Alvarado-Gomez, Federico
Fraschetti F We present a three-dimensional, time-dependent, MHD simulation of the short-term interaction between

a protoplanetary disk and the stellar corona in a T Tauri system. The simulation includes the stellar magnetic field,
self-consistent coronal heating and stellar wind acceleration, and a disk rotating at sub-Keplerian velocity to induce
accretion. We find that initially, as the system relaxes from the assumed initial conditions, the inner part of the disk
winds around and moves inward and close to the star as expected. However, the self-consistent coronal heating andPlanet formation in the PDS 70 system: Constraining the atmospheric chemistry of
9. PDS 70b and c

A. J. Cridland, S. Facchini, E. F. van Dishoeck, M. Benisty F Understanding the chemical link between proto-

planetary disks and planetary atmospheres is complicated by the fact that the popular targets in the study of disks
and planets are widely separated both in space and time. The 5 Myr PDS 70 systems oﬀers a unique opportunity
to directly compare the chemistry of a giant planet’s atmosphere to the chemistry of its natal disk. To that end, we
derive our current best physical and chemical model for the PDS 70 disk through forward modelling of the 12 CO,
C18 O, and C2 H emission radial profiles with the thermochemical code DALI and find a volatile C/O ratio above
unity in the outer disk. Using what we know of the PDS 70 disk today, we analytically estimate the properties ofthe disk as it was 4 Myr in the past when we assume that the giant planets started their formation, and compute achemical model of the disk at that time. We compute the formation of PDS 70b and PDS 70c using the standard coreaccretion paradigm and account for the accretion of volatile and refractory sources of carbon and oxygen to estimate
the resulting atmospheric carbon-to-oxygen number ratio (C/O) for these planets. Our inferred C/O ratio of the gas
in the PDS 70 disk indicates that it is marginally carbon rich relative to the stellar C/O = 0.44 which we derive froman empirical relation between stellar metallicity and C/O. Under the assumption that the disk has been carbon richfor most of its lifetime, we find that the planets acquire a super-stellar C/O in their atmospheres. If the carbon-richdisk is a relatively recent phenomenon (i.e. developed after the formation of the planets at ⇠ 1 Myr) then the planets
should have close to the stellar C/O in their atmospheres. This work lays the groundwork to better understand thedisk in the PDS 70 system as well as the planet formation scenario that produce its planets.

Transition disc nature of post-AGB binary systems confirmed by mid-infrared interferometry
A. Corporaal, J. Kluska, H. Van Winckel, K. Andrych, N. Cuello, D. Kamath, A. Merand F Circumbinary discs

around evolved post-asymptotic giant branch (post-AGB) binary systems show many similar properties to protoplanetary discs around young stars. Deficits of near-infrared (near-IR) flux in the spectral energy distributions (SEDs)of such systems hints towards large dust-free cavities, reminiscent of transition discs as commonly observed aroundTransition disc nature of post-AGB binary systems confirmed by mid-infrared interfer10. ometry
A. Corporaal, J. Kluska, H. Van Winckel, K. Andrych, N. Cuello, D. Kamath, A. Merand F Circumbinary discs

around evolved post-asymptotic giant branch (post-AGB) binary systems show many similar properties to protoplanetary discs around young stars. Deficits of near-infrared (near-IR) flux in the spectral energy distributions (SEDs)of such systems hints towards large dust-free cavities, reminiscent of transition discs as commonly observed aroundyoung stars. We aim to assess the inner rim size of 6 post-AGB binary systems with such a lack in near-IR using
resolved mid-IR high-angular resolution observations of VLTI/MATISSE and VLTI/MIDI. The inner rim of only one
such system was previously resolved. We compare these inner rim sizes to 5 systems with available MATISSE datathat were identified to host a disc starting at the dust sublimation radius. We used geometric ring models to estimate
the inner rim sizes, the relative flux contributions of the star, the ring, and an over-resolved emission, the orientationof the ring, and the spectral dependencies of the components. We find that the dust inner rims of the targets with alack of near-IR excess in their SEDs are 2.5 to 7.5 times larger than the theoretical dust sublimation radii while thesystems that do not show such a deficit have inner rim sizes similar to their dust sublimation radii. Physical radii ofthe inner rims of these transition discs around post-AGB binaries are 3-25 au, which are larger than the disc sizes
inferred for transition discs around young stars with VLTI/MIDI. This is due to the higher stellar luminosities ofpost-AGB systems compared to young stars, implying larger dust sublimation radii and thus larger physical transition
disc inner radii. With mid-IR interferometric data we directly confirm the transition disc nature of six discs aroundpost-AGB binary systems. Future observational and modelling eﬀorts are needed to progress on the structure, origin,and evolution of these transition discs.
5

The impact of dust evolution on the dead zone outer edge in magnetized protoplanetary
disks

Timmy N. Delage, Matías Gárate, Satoshi Okuzumi, Chao-Chin Yang, Paola Pinilla, Mario Flock, SebastianMarkus Stammler, Tilman Birnstiel F [Abridged] Aims. We provide an important step toward a better under-

standing of the magnetorotational instability (MRI)-dust coevolution in protoplanetary disks by presenting a proof

A novel survey for young substellar objects with the W-band filter VI: Spectroscopic
12. census of sub-stellar members and the IMF of Orionis cluster

Belinda Damian, Jessy Jose, Beth Biller, Gregory J. Herczeg, Loic Albert, Katelyn Allers, Zhoujian Zhang,Michael C. Liu, Sophie Dubber, KT Paul, Wen-Ping Chen, Bhavana Lalchand, Tanvi Sharma, Yumiko Oasa F

Low-mass stars and sub-stellar objects are essential in tracing the initial mass function (IMF). We study the nearby
young
Orionis cluster (d⇠408 pc; age⇠1.8 Myr) using deep NIR photometric data in J, W and H-bands from
WIRCam on the Canada-France-Hawaii Telescope. We use the water absorption feature to photometrically selectthe brown dwarfs and confirm their nature spectroscopically with the IRTF-SpeX. Additionally we select candidate
low-mass stars for spectroscopy and analyze their membership and that of literature sources using astrometry from
Gaia DR3. We obtain the near-IR spectra for 28 very low-mass stars and brown dwarfs and estimate their spectral
type between M3-M8.5 (mass ranging between 0.3-0.01 M ). Apart from these, we also identify 5 new planetary mass
candidates which require further spectroscopic confirmation of youth. We compile the comprehensive catalog of 170
spectroscopically confirmed members in the central region of the cluster, for a wide mass range of ⇠19-0.004 M .
We estimate the star/BD ratio to be ⇠4, within the range reported for other nearby star forming regions. With theupdated catalog of members we trace the IMF down to 4 MJup and we find that a two-segment power-law fits the
sub-stellar IMF better than the log-normal distribution.

Toward a 3D kinetic tomography of Taurus clouds: II. A new automated technique andits validation
Q. Duchêne, C. Hottier, R. Lallement, J. L. Vergely, C. Babusiaux, A. Marchal, F. Arenou F Three-dimensional(3D) kinetic maps of the Milky Way interstellar medium are an essential tool in studies of its structure and of starformation. We aim to assign radial velocities to Galactic interstellar clouds now spatially localized based on starlight
extinction and star distances from Gaia and stellar surveys. We developed an automated search for coherent projections
on the sky of clouds isolated in 3D extinction density maps on the one hand, and regions responsible for CO radio
emissions at specific Doppler shifts on the other hand. The discrete dust structures were obtained by application of
the Fellwalker algorithm to a recent 3D extinction density map. For each extinction cloud, a technique using a narrowa 3D kinetic tomography of Taurus clouds: II. A new automated technique and
13. Toward
its validation
Q. Duchêne, C. Hottier, R. Lallement, J. L. Vergely, C. Babusiaux, A. Marchal, F. Arenou F Three-dimensional(3D) kinetic maps of the Milky Way interstellar medium are an essential tool in studies of its structure and of starformation. We aim to assign radial velocities to Galactic interstellar clouds now spatially localized based on starlight
extinction and star distances from Gaia and stellar surveys. We developed an automated search for coherent projections
on the sky of clouds isolated in 3D extinction density maps on the one hand, and regions responsible for CO radio
emissions at specific Doppler shifts on the other hand. The discrete dust structures were obtained by application of
the Fellwalker algorithm to a recent 3D extinction density map. For each extinction cloud, a technique using a narrowsliding spectral window moved along the contour-bounded CO spectrum and geometrical criteria was used to selectthe most likely velocity interval. We applied the new contour-based technique to the 3D extinction density distribution
within the volume encompassing the Taurus, Auriga, Perseus and California molecular complexes. From the 45 clouds
issued from the decomposition, 42 were assigned a velocity. The remaining structures correspond to very weak COemission or extinction. We used the non-automated assignmentsof radial velocities to clouds of the same region
6
presented in paper I and based on KI absorption spectra as a validation test. The new fully automated determinations
were found in good agreement with these previous measurements. Our results show that an automated search basedon cloud contour morphology can be eﬃcient and that this novel technique may be extended to wider regions of the
Milky Way and at larger distance. We discuss its limitations and potential improvements after combination with othertechniques.

Modeling Two First Hydrostatic Core Candidates Barnard 1b-N and 1b-S

Hao-Yuan Duan, Shih-Ping Lai, Naomi Hirano, Travis J. Thieme F A first hydrostatic core (FHC) is proposed

to form after the initial collapse of a prestellar core, as a seed of a Class 0 protostar. FHCs are diﬃcult to observe
because they are small, compact, embedded, and short lived. In this work, we explored the physical properties of two
well-known FHC candidates, B1-bN and B1-bS, by comparing interferometric data from Submillimeter Array (SMA)
1.1 and 1.3 mm and Atacama Large Millimeter/submillimeter Array (ALMA) 870 µm observations with simulatedsynthesis images of the two sources. The simulated images are based on a simple model containing a single, hot

Two First Hydrostatic Core Candidates Barnard 1b-N and 1b-S
14. Modeling
Hao-Yuan Duan, Shih-Ping Lai, Naomi Hirano, Travis J. Thieme F A first hydrostatic core (FHC) is proposed

to form after the initial collapse of a prestellar core, as a seed of a Class 0 protostar. FHCs are diﬃcult to observe
because they are small, compact, embedded, and short lived. In this work, we explored the physical properties of two
well-known FHC candidates, B1-bN and B1-bS, by comparing interferometric data from Submillimeter Array (SMA)
1.1 and 1.3 mm and Atacama Large Millimeter/submillimeter Array (ALMA) 870 µm observations with simulatedsynthesis images of the two sources. The simulated images are based on a simple model containing a single, hot
compact first-core-like component at the center surrounded by a large-scale, cold and dusty envelope described bya broken power-law density distribution with an index, ↵. Our results show that the hot compact components of
B1-bN and B1-bS can be described by temperatures of ⇠ 500 K with a size of ⇠ 4 au, which are in agreement withtheoretical predictions of an FHC. If the ↵ inside the broken radii is fixed to -1.5, we find ↵ ⇠ -2.9 and ⇠ -3.3
outside the broken radii for B1-bN and B1-bS, respectively, consistent with theoretical calculations of a collapsing,bounded envelope and previous observations. Comparing the density and temperature profiles of the two sources withradiation-hydrodynamic simulations of an FHC, we find both sources lie close to, but before, the second collapse stage.
We suggest that B1-bS may have started the collapsing process earlier compared to B1-bN, since a larger discontinuity
point is found in its density profile.

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

Alessia Franchini, Alessandro Lupi, Alberto Sesana, Zoltan Haiman F The shrinking of a binary orbit driven

by the interaction with a gaseous circumbinary disc, initially advocated as a potential way to catalyze the binary
merger, has been recently debated in the case of geometrically thick (i.e. with H/R & 0.1) discs. However, a clear
consensus is still missing mainly owing to numerical limitations, such as fixed orbit binaries or lack of resolution
inside the cavity carved by the binary in its circumbinary disc. In this work, we asses the importance of evolving thebinary orbit by means of hydrodynamic simulations performed with the code gizmo in meshless-finite-mass mode. In
order to model the interaction between equal mass circular binaries and their locally isothermal circumbinary discs,