THE STAR FORMATIONNEWSLETTER
No. 338 27-33

2021. 4. 30 泉奈都子（ASIAA）

27. Constraining Protoplanetary Disk Accretion and Young Planets
Using ALMA Kinematic Observations
28. Accretion and outflow activity in proto-brown dwarfs
29. GASTON: Galactic Star Formation with NIKA2. Evidence for themass growth of star-forming clumps
30. C18O, 13CO, and 12CO abundances and excitation temperaturesin the Orion B molecular cloud: An analysis of the precisionachievable when modeling spectral line within the Local
Thermodynamic Equilibrium approximation
31. Dissecting the super-critical filaments embedded in the 0.5 pc
subsonic region of B5
32. High-accuracy estimation of magnetic field strength in theinterstellar medium from dust polarization
33. Outflows, envelopes, and disks as evolutionary indicators in
Lupus YSOs

31. Dissecting the super-critical filaments embeddedin the 0.5 pc subsonic region of Barnard 5
Schmiedeke et al.

https://arxiv.org/pdf/2101.00248v1.pdf

Subsonic region で検出されたフィラメント構造の詳細な性質を求める（研究の目標はフィラメントの分裂過程について明らかにすること）(Pineda et al. 2015)• Observation- Target: Perseus star-forming regionにあるBernard 5 (B5)

‣ D = 302 ± 21kpc‣ Nearly constant subsonic non-thermal velocity dispersion‣ Filament structure (1 YSO, 3 gravitationally bound dense gas condensations)→ Results of fragmentation of the dense gas filament- Telescope : JCMT (450, 850μm continuum), GBT, VLA (NH3(1,1), NH3(2,2))- Resolution: 450μm - 3000au, 850μm - 4400au, NH3(1,1) , NH3(2,2) - 1800 au

このフィラメント構造の性質を求める

Pineda et al. (2010)

Pineda et al. (2015)• Results- 細かい構造の検出• Results- フィラメント構造の性質‣ Plummer function(model of cylindrical filament)r : cylindrical radius
n0. : central density of the cylinder
R. : projected radius
Rflat : radius of the flat inner section of thecylinder
Ap. : finite constant factor
p : density profile power-low index
Σbkg : background surface density
nbkg : background density‣ Gaussian
AG : amplitude
σG : varianceμG : expected value‣ Bz ~ 500 μG (upper limit)‣ M/L ~ 80M⦿pc-1(highly super-critical)‣ FWHM ~ 2 × Rflat

flat, Central densityとRflatに相関‣ pとRが見られる

33. Outflows, envelopes, and disks as evolutionary
indicators in Lupus YSOs
Vazzano et al.

https://arxiv.org/pdf/2101.05330v1.pdf

Prestellar ~ Protostellar の異なる進化段階の天体について、よく使用されている進化段階のトレーサー（Tbol, outflow…）の検証を行い、一貫性があるかどうか調べる• Sample- Lupus complex に存在する7天体 (Prestellar - Protostellar)‣ SOLA(The Soul of Lupus with ALMA, Saito et al. 2015) を元に選出（可視-cm波のデータによるSED fittingで進化段階を推定）‣ Protostellar candidate: Single source (non-multiple)‣ Prestellar candidate: density greater than critical density (mot transient clumps)
同じ環境下（nterstellar radiation field, gas temperature, chemical composition）
かつ同じ観測設定（beam size, distance, spatial resolution, sensitivity）のもとでトレーサーの検証が可能

and Archive data (ALMA)• Observation- SOLA observations~ 8” : 1240 AU)‣ ALMA 7m array and TP (resolution‣ Band6 (1.3 mm continuum, 12CO(2-1), SiO(5-4), N2D+(3-2), C18O(2-1))- ALMA archive continuum data
‣ Band 3, 6, 7, 8
- ALMA archive molecular data
‣ Band 6 (12m, 7m, TP)• Results• Results- Outflow structures
Cleary detected outflows

Signs of the presence of outflow• Results-進化段階の検証‣ SED (Tbol, Lbol/Lsubmm, Mdisk/Menv, spectral index α, β)✓ Tbol, Lbol/Lsubmm, Mdisk/Menv は 進化段階をトレース（特にProtostellarのClass）しているようだが、完全ではなく同じような進化段階にある天体に関してはその詳細を調べるのは難しい✓

Spectral index α (IR), β (millimeter)は今回の天体に関しては使えなかった‣ Chemical evolution (N2D+, DCN, N2H+, HCN, CO, CH3OH, SO, SiO)
✓DCN, N2D+が検出された天体は若い、CH3OH, SO, SiOは若いアウトフローをトレースしている可能性がある、、などと判断できるが、 Shock chemistoryを考慮すると複雑になり、注意が必要‣ Outflow evolution (opening angle, velocity extent, momentum, energy,

mass-loss rate, momentum flux…)✓ Outflowの特徴だけで進化段階を区別するのは難しい (これまで示唆されていた、opening angleが進化とともに大きくなる、長さは短くなる、等の傾向は確認されなかった。
✓ただし、今回のサンプルではenergyやmomentum fluxと年齢に相関が見られた

27. Constraining Protoplanetary Disk Accretion andYoung Planets Using ALMA Kinematic Observations
Rabago et al.

https://arxiv.org/pdf/2102.03007v2.pdf

ALMAの観測が1)降着メカニズムと2)惑星の性質の解明にどのように活用できるか検証28. Accretion and outflow activity in proto-brown dwarfs
Riaz et al.

https://arxiv.org/pdf/2012.08612.pdf

近赤外の分光-撮像観測でproto-BDのaccretionとoutflow活動を調べた

29. GASTON: Galactic Star Formation with NIKA2.
Evidence for the mass growth of star-forming clumps
GASTON collaboration, Rigby et al.

https://arxiv.org/pdf/2101.08811v2.pdf

30. C18O, 13CO, and 12CO abundances and excitation temperaturein the Orion B molecular cloud: An analysis of the precisionachievable when modeling spectral line within the Local
Thermodynamic Equilibrium approximation
Roueff et al.

https://arxiv.org/pdf/2005.08317v1.pdf

Orion B molecular cloudにおいてC18O, 13CO, 12COの性質をCRB法を用いて調べた32. High-accuracy estimation of magnetic field strength
in the interstellar medium from dust polarization
Skalidis and Tassis

https://arxiv.org/pdf/2010.15141v2.pdf

ISMにおける新たな磁場強度の測定方法の確立