Star Formation Newsletter No. 327, #37-43
37. Intermittent planet migration and the formation of multiple dust ringsand gaps in protoplanetary discs, Gaylor Wafflard-Fernandez , Clément
Baruteau, MNRaS, 493, 5892 (2020)
38. Architecture of Three-planet Systems Predicted from the Observed
Protoplanetary Disk of HL Tau, S. Wang et al. ApJ, 891, 166 (2020)
39. GMC Collisions as Triggers of Star Formation. VII. The Effect ofMagnetic Field Strength on Star Formation, B. Wu et al. ApJ, 891, 168(2020)
40. Constraining the Infalling Envelope Models of Embedded Protostars:
BHR 71 and Its Hot Corino, Yao-Lun Yang et al. ApJ, 891, 61 (2020)
41. Rapid Evolution of Volatile CO from the Protostellar Disk Stage tothe Protoplanetary Disk Stage, Ke Zhang et al. ApJL, 189, L17 (2020)
42. Excess C/H in Protoplanetary Disk Gas from Icy Pebble Drift Acrossthe CO Snowline, Disk Stage, Ke Zhang et al. ApJL, 189, L16 (2020)
43. The VMC survey – XXXVI. Young stellar variability in the Large
Magellanic Cloud, V. Zivkov et al. MNRaS, 494, 458 (2020)
花輪 知幸

37. Intermittent planet migration and the formation of multiple dust rings andgaps in protoplanetary discs, Wafflard-Fernandez+ MNRaS 493, 5892 (2020)
migration する惑星1つで複数のリングを作る
2D Hydro (planet, gas, dust) + 3D rad. model
ガスの自己重力は入れているがToomre's Q は大きい
ガスは local
isothermal: T(r)dustの運動のbackreactionなし

粘性が小さい時に起きる

擬似観測runaway migration
runaway: m > Mp

惑星に働くトルクとその反作用⌃(r)rp [!(r)!p ]"⌃m = 4⇡rp !(rp ) ⇥ xs (rp!

xs )Z rp#⌃(r) dr ,rp x s !

Architecture of Three-planet Systems Predicted from the Observed Protoplanetary日本人共著者: 金川, 林, 須藤
Disk of HL Tau, S. Wang et al. ApJ, 891, 166
HL disk 内にあると思われる惑星の将来

migrationeccentricity damping円盤が消失するまでの6 Myr

その後の10Gyr39. GMC Collisions as Triggers of Star Formation. VII. The Effect ofMagnetic Field Strength on Star Formation, B. Wu+, ApJ, 891, 168 (2020)
24 modelsdensity- and magneticallyregulated star formation
subgrid models
GMC collisions enhance starformation rates and efficiencies
in magnetically supercriticalconditions, but may actuallyinhibit them in themagnetically critical case.

日本人共同研究者: 中村10μG

衝突なし

50μG

10μG
衝突あり

50μG

40. Constraining the Infalling Envelope Models of Embedded Protostars:
BHR71 and its Hot Corino, Y.L. Yang et al. ApJ, 891, 61 (2020)
理研

33 pages

BHR 71 IRS1 ALMA obs.

1.
2.
3.

infall signature “inside-out model” τ = 12,000 ± 3,000 yr
CH3OH, CH3OCHO, H2CS, SO2 and HCN ν 2 = 1. (hot corino)
13C-methanol velocity gradient (< 50 au) Kepler disk?
continuumoutflow

見つかった遷移のリスト

infall の証拠
blue asymmetric double-peaked profiles

best fit infall model

The moment 1 maps ofthe unblended COMemission

41. Rapid Evolution of Volatile CO from the Protostellar Disk Stage to theProtoplanetary Disk Stage, Ke Zhang et al. ApJ, 891, L17
13C18Odisk
CO gas abundance is consistent with the ISM within a factor oft two.

42. Excess C/H in Protoplanetary Disk Gas from Icy Pebble Drift Across the CO
Snowline, Ke Zhang et al. ApJL, 891, L16
木星, 土星, 大質量系外惑星でC/Hが高いのは何故か
COが pebble になってdriftするから

HD 163296 (NOEMA)

R3, R4, D3, D4 が fit

43. The VMC survey – XXXVI. Young stellar variability in the Large
Magellanic Cloud, V. Zivkov et al. MNRaS, 494, 458 (2020)
金属度の低い大マゼラン雲で変光星(近赤外)の統計を調べる
対象 3062 の変光星 (調査は362,425星)(i) massive YSO では173星で近赤外の測光, 39星が有意な変光(ii) 変光するYSOは平均に比べて赤い (若い)(iii) 変光の度合いは moderate (0.1 mag<ΔKs<0.6 mag) 例外3(iv) 12 eruptives, 10 faders, 7 dippers, 8 short-term variables (STVs), 3 long-periodvariable YSOs (LPV-YSOs), and 1 unclassified object.
(v) 長期的な色の変化はない(あるいは暗くなる時に青くなる)。降着率の変化が変光を生むと考えてよい。
(vi) 周期が2d-10d の変光星が(たった)2つ見つかった。
(vii) SpitzerのサンプルにないのでYSOとはしていないが、ΔKs > 1 magの候補星が40mある。領域は重なるのでYSOかもしれない。
(viii) LMCでもYSOは変光はcommon。銀河系との統計的な有意な差はない。
(ix) 変光の振幅は銀河系と同じかやや小さい。(原因は不明)