The Star Formation Newsletter#315, 44-46#316, 01-07
島 和宏

2019/0544

https://arxiv.org/abs/1902.02052

A&A proofs: manuscript no. gaiaMCdisArxiv

AG1 kpc from the Sun and are still located in the Galactic plane 1 depicts the extinction AG feature of on- (green) and o↵-cloud(Magnani et al. 1996; Schlafly et al. 2014), They tend to occupy (blue) stars.
large areas on the sky, making them able to optically extinct a
In the second step, the distances are determined usinglarge number of stars. Consequently, the extinction AG imposed Bayesian inference with on-cloud stars and are subsequently
on stars behind molecular clouds is able to be investigated statis- confirmed with o↵-cloud stars by eye. We use two moleculartically.
clouds, Taurus (Pineda et al. 2010; Ward-Thompson et al. 2016)
We selected Gaia DR2 stars according to their parallaxes and and Gemini (Li et al. 2015), to illustrate the process of determinextinction AG . First, we removed those stars with parallaxes < ing distances.
0.5 mas, corresponding to an upper distance threshold of 2 kpc.
Molecular clouds at high Galactic latitudes are usually near theSun (< 1 kpc), and a 2-kpc cuto↵ suffices for our study. If the relative errors of stellar parallaxes exceed 20%, the corresponding
distances would di↵er from the reciprocal of their parallaxes by
・Gaia DR2を使用
Cloud distancea large amount (Bailer-Jones 2015), and consequently, we only
kept those stars whose relative parallax errors are less than 20%.
・AGのブレイクポイントから分子雲の距離を同定
As to the extinction AG , we require AG > 0, which rejects 13stars. In total, we have 30,259,242 Gaia stars meet the criteria.
On-cloud stars
・計52個、うち13個は今回で初めて距離がわかった
The extinction AG error of a single star, AG , is estimatedwith1
AG =84th_percentile 16th_percentile .
(1)
2
Oﬀ-cloud stars
where 84th_percentile and 16th_percentile are provided in Gaia
DR2. To derive the distance and its standard deviation, we drew
10000 samples from the Gaussian distribution N($, $), where$ and $ are the parallax and its error in Gaia DR2, and theDistancemean and standard deviation of the distance correspond to themean and standard deviation of the reciprocal of the 10000 sam- Fig. 1: The extinction AG of on- (green) and o↵-cloud (blue)stars. The vertical black line marks the distance of the molecularples, respectively.
We used Planck 857-GHz images (Planck Collaboration cloud.
et al. 2014) to trace the molecular clouds rather than IRAS 100-

45

https://arxiv.org/abs/1811.04381

・SiO, SO2, H2S, CH3OH, H2COで観測
SiO：disk, inner envelope, jetをトレース
CH3OH, H2CO：infalling-rotating envelopeをトレース
SO2, H2S：diskのouter partをトレース
・Core Accretion モデルを支持

Motivation:
massive protostarの降着過程が知りたい
Target:G339.88-1.26 (IRAS 16484-4603)
d1.3= mm
2.1continuum
kpc
map of G339.88-1.26.

(b)

1.
our levels are 3 , 6 , 12 , 24 , ..., with 1 =beam 1 . The synthesized beam is 0.2900 ⇥ 0.2100
Observations:. = 28.2 . The R.A. and Dec. o↵sets areo theALMA
continuum
position(↵2000 , 2000 ) =in peakBand
64s .663, 46 080 3300 .88).

ssuming 70 K. This is most likely to be a lower(1.3
the gas mass due to the resolving
outmm)
of moreemission, which suggests that there is enoughfor future growth of the massive protostar. Theof the continuum emission within 0.500 (1,000the immediate compact structure around therotostar, is 0.16 Jy, which corresponds to a gas
13 M , assuming a dust temperature of 30 K,
th 70 K, or 1.6 M with 200 K, considering
her temperatures close to the protostar (Zhang018). The continuum fluxes of the sources inand northwest are 0.032 and 0.027 Jy, respechich correspond to gas masses of 2.2 and 2.6M

bipolar outﬂow

Figure 2. (a): Integrated maps of the blue-shifted and12
red-shifted
CO view(21) emissions in blue and red color
edge-onscales, overlaid with the integrated SiO (54) emission

Ordered Envelope-disk Transition in G339.
SiO jetと垂直に切ったPV図(a)(e) SiO
SO218O(b)HC2S(f)(c) CH3OH(d) H2CO

遠心力バリア diagrams of theKeplerianFigure 6. Position-velocity
SiO (panelrotationa), C18 Ocurve(panel b), CH3 OHe), and H2 S (panelf) 6emissions
to the SiO jet and through tvCB =km/s along cuts perpendicularm d = 11 Msun 00* the cuts is 0.3 . The grey contours
in color scales and grey contours. The width of+ disk mass)In pa
rCB =5301(1 = 2.3, 5.6, 4.2,4.0,2.4,auand 2.4 mJy beam(protostellar
in panels (a)mass(f), respectively).

Implications for Massive Star Formation
今回のTarget
・G339.88-1.26 (IRAS 16484-4603)

rCB = 530 au

low-mass protostarsと違うところ
・遠心力バリアが典型値(<200 au)より大きい
low-mass protostarsと同じところ
・highly collimated outﬂow
・transition from an infalling-rotating envelope to Keplerian disk

得られた示唆
massive star formation は low-mass のスケールアップ版だろう(core accretion シナリオ)

46https://arxiv.org/abs/1902.03673

3The weakening outburst of V582 Aur
2016

Magnitude

・V582 Aur (オリオン座FU型星)を長時間観測
・あと80年ぐらいで明るさの変化は落ち着くだろう・accretion diskのモデル化の参考になる？

2017
A

S

O

N

DJF

2018
M

6A

M

J

J

A

S

O

N

D

JF

2019
M

A

M

J

J

A

S

O

N

D

J

F

M

A

W2
W1

8KK

H

10

H

H

J
J
12
I

I
14

R

I
R

V

R

16

V
V

B
B

18
B
20
7600

7800

8000

8200

8400

8600

JD (2,450,000 + )Figure 1. Light curves of V582 Aur. Filled circles represent data from this work, plus signs are from A18, and empty circles
are the latest data from the ASAS-SN sky survey (Shappee et al. 2014; Kochanek et al. 2017). The new mid-infrared WISE
data points are marked with squares. Tick marks on the top indicate the first day of each month. The measured errors are

01

IR region of the SED, which are known as Lada indices
The YSOs can be classified as Class 0, Class I, Clas
IIhttps://arxiv.org/abs/1903.01070
and Class III, based on the steepness of the indiceat various wavelength intervals (Lada 1987; Andre et al1993). The estimation and analysis of Lada indices arvery important in studying the evolution of HAeBe staras it gives an idea about the evolution of the CSM. Th
equation defining the spectral index (Lada 1987; Wilking
1989; Greene et al. 1994) is expressed as,λ F

nλ1 −λ2 =log( λ21 Fλλ2 )1log( λλ12 )(10For our analysis we consider the spectral index
n2−4.6 , which is the ratio of the flux values at 2MASS(Skrutskie et al. 2006) Ks -band (i.e., λ1 = 2.159 µmand WISE (Cutri et al. 2013) W2-band (i.e., λ2 = 4.
µm). The age estimates are available only for 110 stars
However, the spectral index is not calculated for th
HAeBe stars CPD-61 3587B and LkHA 224 due to th
unavailability of WISE magnitudes. Hence, a sample o
108 stars is used for this analysis.

・Gaia DR2を使用
・photometryと距離からHAeBeのageとmassを推定・BeとAeでディスクの構造が違いそう？

Figure 5. Figure illustrates the log-log plot of Ṁacc andstellar mass for a sample of 106 HAeBe stars. The solid

02

https://arxiv.org/abs/1903.03540

A&A proofs: manusc

・どんな惑星が中心星に落ちずに生き残れるか・分子雲のcollapseから計算
・いろんな惑星がtype-I migrationから逃れられる

cH
att
I
cwtpdyta

03

https://arxiv.org/abs/1903.08283

12・ディスクのダスト質量を推定する
・Taurusにある132個のprotoplanetary diskについてRTモデルでSEDをﬁttingした・(sub-)milimeter photometry を使った推定値よりダスト質量が1-5倍重い

B

10

1

100

10102

10

1

100-1

10 -1
10 -2

10 -2

10 0

10 2

04

・ALMAを使って2つのYMC progenitorを観測
・C3H2(7-6)で最も密度の高いガスをトレース
・初めて重力収縮していることを確認

https://arxiv.org/abs/1903.06158

05https://arxiv.org/abs/1903.06537

・MWC 758 (Herbig A5 star)のdiskで２つのclumpが観測されている
・dust-trappingシナリオをシミュレーションで再現simulation

ALMA
bandin7 theobservation
Two vortices
MWC 758 discKepler
rotation

vortexdust
trapping

2つの巨大惑星によるもの

Particles

AzimuthModel & Methods

00.004-4-1
10・2D gas (isothermal) + dust hydrodynamical simulation・gas self-gravity (実は重要)-2
・惑星はmigrateしない・gap -> Rossby wave
instability -> dust trapping-3
10-5100・constant120 140 alpha turbulent
4060 viscosity
80 100 ->120
140
内側でringを形成
0.002

080
Radius [au]rtensity at 1277 orbits
0.00.40.81234

Radius [au]Perturbed vortensity at 1277 orbits
-0.8
-0.4
0.0
0.4
0.8
432

10.5

1.00-0.5

0.0

0.5

1.0

3gap

Azimuth [rad]21.5 Msun

80
100
Radius [au]1.5 Mj@ 35 au
120

140

10-2

0.010

0.008

10-3

1gap

0.006

00.00410-4-1-20.002

-3

04060

80 100Radius [au]1205 Mj @ 140 au

140

12

3

4

10-5

Particles size [m]

0.0

06

https://arxiv.org/abs/1903.05106

6E. R. Beasor et al.

Figure 4. Plot showing best fitting isochrones from each of the three age e
isochrones represents the main sequence. The purple star symbol indicates t

・星団はSSPsでは説明できない・明るい星はmergeによるものだろう07

https://arxiv.org/abs/1903.07610

14Biazzo, Beccari, De Marc

・LH95にあるlow-mass PMSをHSTで観測
・accretion luminosityの時間変化が普通よりゆっくり-> metallicityが重要なパラメータ

Figure 8. Accretion luminosity versus stellar luminosity.
Circle and diamond symbols are as in Fig. 5. Dashed lines

pearsand hagreem
ments
shadetion oThesecreasistars(see dal. 20of thiby us
again
dates
thanGalac
kpc;
ports
accordthe lo