THE STAR FORMATIONNEWSLETTER
No. 286 (#21-25)
塚越崇(茨城大)9 Dec. 2016

1. Photochemical-dynamical models of externally FUV irradiatedprotoplanetary discs
2. Seeding the Galactic Centre gas stream: gravitational instabilities
set the initial conditions for the formation of protocluster clouds
3. The Gaia-ESO Survey: Lithium depletion in the Gamma Velorum
cluster and inflated radii in low-mass pre-main-sequence stars
4. The Spatial Distribution of Complex Organic Molecules in theL1544 Pre-stellar Core
5. A correlation between chemistry, polarization and dust properties
in the Pipe Nebula starless core FeSt 1-457

Photochemical-dynamical models of externally FUV irradiated protoplanetary discs
T.J. Haworth et al.

• external FUVを入れたfull radiation hydrodynamic simulation• 円盤外側でのflowを真面目に計算• 新いアプローチの説明とsemi-analyticモデルの確認[Adams+2004, Facchini+2016]• 今後の研究の礎• flowのモデル• TORUS-3DPDRコード[Bisbas+2015b]を使用• 33 gas species and 330 chemical reactions (温度に~10% error)• UV場は遠方から一様にdisk edgeに入る• dust to gas ratio=1E-5 (small dustのみがflowに存在)• PDRの温度・化学はiterativeに解く、PDRと流体構造もiterativeに解く• 6つの構造モデルで計算(Model A~F)
• disk outer radius, FUV field, and optical thicknessなどを変化• 円盤物理構造は固定

T. J. Haworth et al.

50

Semi-analytic estimate
Numerical models

Simulation
Semi-Analytic

1100

30-81000-9-1020900

108000-11A

BC

ModelDEF

Figure 5. The mass loss rate for each model in this paper, both for the semi–
analytic estimates and numerical models. Note that in the case of model E
the mass loss rates are indistinguishable.

• semi-analyticモデルとconsistent• FUVに対し光学的に薄いモデルでは100
800Our critical radius
Semi-analytic critical radius(model C)、円盤外縁部でCOが多く残6040存。また回転がsub-Keplerとなる。
200=>irradiated diskのindicatorになるか-20も？

-40-60-80

700

200 400 600 800 1000 1200 1400 1600 1800 2000 2200

R, AU600
Figure 9. The dust and gas temperature profiles for model A (without theimposed disc temperature structure discussed in section 3.3). The black ver500
tical line represents the disc outer edge and the red vertical line the location
400of the H–H2 transition. In model A, the disc outer edge is optically thickto the incident FUV and the H–H2 transition takes place at some point in300the flow (at ∼ 380 AU). This transition marks the point at which the opticaldepth approaches unity, the temperature in the flow decreases substantially200
B transitions
C occur.DEFand a numberAof chemical

ModelFigure 7. A comparison of the semi–analytic critical radii and approximate
10
Keplerian velocity
estimates of the critical radius derived from our simulations.
Model C
Disc outer radius
H-H2 transition

8 to critical radii a factor of a few times larger than the sonic ralead
dius. They also found that the mass loss rates could sometimes belower than Adams et al. (2004) predict by up to an order of mag6nitude(though this could, in part, be due to diﬀerences in the PDR
code employed). Here, we have verified that the solutions including
the non–isothermal terms are accurate when compared with consis4
tent dynamical models.
Finally we note that given the semi–analytic solutionsare2 accurate, they can make useful benchmarks for future
photochemical–dynamical codes (though due care is required regarding capturing of the disc outer edge, either using high resolution
0 or forcing cells there).

Azimuthal velocity, km/s

-12

LHS of equation 14nst

R, AU

40
1200

Critical Radius, AU

Mass loss rate, log10(Msol/year)-7

Temperatur

1010100R, AU

1000

3rstt

4inebcw
taHIpA

W
mcaFw
32Mbb

Seeding the Galactic Centre gas stream: gravitational instabilities set the initial conditions for theformation
J. D.
Henshaw etofal.protocluster clouds
J.D. Henshaw et al.

ure 1. The Herschel-derived molecular hydrogen column density map of the CMZ (Battersby et al. in preparation). The black contours represent thegrated emission from N2 H+ J = 1 ! 0. Contour levels represent 1, 10, 50, and 90 per cent of peak emission. The orbital solution of Kruijssen et al. (2015)
ighlighted by the blue line. The portion relevant to this study is indicated by the solid line. The black dashed and black dot-dashed rectangle reflect theon of interest to the present study and the dust ridge, respectively. The scale bar assumes a distance of 8.3 kpc (Reid et al. 2014).

• CMZのdust ridge cloudの初期状態を調べるため、上流にあるガスの運動を調べる• Mopra CMZ surveyのデータを使用[Jones+2012]

1; Caswell et al. 2010), towards Sgr B2, which displays promiure 1 is a map of the inner CMZ. The colour-scale represents thet star formation activity (see above). The coherency of the dust
Herschel-derived column density (Battersby et al. in preparation).
N2H+(1-0),
Dendrogramを使った構造抽出
ge gas stream is supported by the comprehensive decomposition
The present investigation focuses on the region 0. 7 < l < 0. 0,
he complex molecular gas kinematics performed by Henshaw
0. 1 < b < 0. 1, which is indicated by the black dashed rectanl. (2016). In this scenario, star formation is initiated at a comgle. The black contours highlight integrated emission of N2 H+ . Then zero point, triggered as the gas clouds are tidally compresseddata enclosed within the black dashed rectangle were analysed usFigure 2.
Galactic longitude versus: (A) Galactic latitude. A column dening their pericentre passage at ⇠ 60 pc from the bottom of theing the Semi-automated multi-COmponent Universal
Spectral-line
sitymapofthe CMZ focusing on the region of interest (Battersby et al. in1
actic gravitational potential (Kruijssen et al. 2015). Dynamicalfitting Engine (scouse ; Henshaw et al. 2016).
preparation).
The colour scale and blue solid line are equivalent to those inλ~22.5±0.1
pc(inclination補正後)でフィット
deling of the gas stream vel
performed by Kruijssen et al. (2015),
Fig.
1.
The
contours
refer to dendrogram-identified structures. The red condicts that G0.253+0.016 and Sgr B2 are separated by 0.43+0.22
tours are those spatially associated with the corrugated velocity field; (B)0.08r, which corresponds to a single free-fall time (t↵ ⇠ 0.34 Myr).
vLSR . The data points refer to the centroid velocities of spectral components
3 RESULTS
he context of the proposed evolutionary timeline, this result sugextracted using scouse (blue data points in panel A); (C) residual velocity
afterremoval of a linear velocity gradient (Equation 1 and § 3). The redts that once star formation
has been initiated, it happensは~8pc
rapidly.
A of Fig. 2 provides a close-up view of theHerschel-derived
minimumな間隔λ≒λPanelsepJ(~6pc)
dashed line represents the best-fitting solution to a sinusoidal model used
The question is whether it is reasonable to assume that thecolumn density map (Fig. 1). It focuses on the location of the upto describe the blue data points. Grey data points indicate those that are
uds have similar initial conditions, such that the tidal compresstream velocity field (depicted by the blue dots).
To identify
the process (see § 3).
excluded
from the fitting
最大波長λは~22pc~>
λ~17pcvelTn at pericentre causes them to evolve and form stars on simimain structures we use dendrograms (Rosolowsky et al. 2008).

•• 速度パターンに揺らぎを発見=>ピークにガスが集積する様子•• ジーンズ長, Toomre lengthと比較••• 速度パターンがgas streamの重力不安定の要因か影響なのかは不明

gasのtraffic jamによって不安定となったのか、その逆か？

The Gaia-ESO Survey: Lithium depletion in the Gamma Velorum cluster and inflated radii in lowmass pre-main-sequence stars
R.D. Jeffries et al.

• 実際に観測される星の半径は理論より~10%ほど大きい=>温度や光度(質量や年齢)見積もりに影響を与える• dynamo-generated magnetic activityで説明できる• pre-main sequenceでも同じかもしれないので、radial inflationを調べる• Gaia-ESOサーベイのデータを使用• クラスターに対するunbiased survey, Gamma Vel. clusterのデータを使用• Prisinzano+2016で導出したPMS memberをターゲットに解析
Inflated radii in PMS stars• 測光データとLi spectrum

• PMSが標準モデルより大きい半径を持ちTeffが小さくなっていれば？
=>Li depletionが遅くなり、より後期で生じる• Jackson&Jeffries(2014a)に乗っ取ってstarspotsの影響を考える• R*, L*, Teffが変化

6

R. D. Jeffries et al.

The Spatial Distribution of Complex Organic Molecules in the L1544 Pre-stellar Core
I. Jimenez-Serra et al.

• 低温コアにおけるCOMsのdepletionを調べる• pre-stellar core L1544– 16 –• IRAM30mによる3mm帯の高感度観測• コア中心と4000au離れた箇所(CH3OHでbright)のCOMsスペクトルを取得し比較• O-bearingは
CH3OH-pで強い• N-bearingは中心で強い• rotation diagramによるTex導出• 5-6 K at center, 5-8 Kat CH3OH-p

τm , optical depth of the main component. (See Estalella 2016, for further details of the HfS fitting procedure.)

A correlation between chemistry, polarization and dust properties in the Pipe Nebula starless core
FeSt 1-457
with Aguti
C. Juarez
et al.et al. 2007) except at the southwestern corner where
the ratio seems to be more balanced.

• FeSt 1-457 (d~145pc)
3.1.2. PdBI dataglobule, 4M⦿ pre-stellar core
•In BokFigure 3 we show a section of the channel map showing theN2 H+ (1−0) emission
detected with the PdB interferometer. TheIRAM30m• weak emission (6σ)&isPdBIによる観測
better detected in the second panel corresponding to the strongest line of the three central hyperfine lines,line
3mm連続波
•at N2H+a velocity&of3mm
5.80 kms−1 .survey,
The last panelof Fig. 3 shows thespectra (in red) at the position of the 6σ detection. The IRAM
単一鏡+干渉計combineもspectra (in black) is also shown as comparison, and we can•30m
see that the hyperfine structure is also seen in the PdBI spectrum
indicating that indeed there is a real N2 H+ detection from thePdBI. The emission filtered out by the PdBI with respect to the30m is estimated to be ∼ 98%, from a comparison of theisothermalではズレがあり、温度構造を入れる•IRAM
PdBI spectra (convolved with a Gaussian to obtain the IRAMとよく合う30m
beam size) and the IRAM 30m spectra at the peak position.
Fig. 4. Color scale: Moment-zero map of the IRAM 30m and PdBI
Given the smallest antenna baseline of PdBI observations, the combined data. Contours are 57, 67, 77, 88, 97, 99.5, 100 percent ofangular scale detectable by the PdBI observations is ∼ 12 the peak, 1 Jy beam−1 km s−1
コアの物理モデルとして使用•largestarcsec or ∼ 1700 au (following Appendix of Palau et al. 2010).
Thus, about 98% of the emission detected with the IRAM 30m
comes from structures at scales ≥ 1700 au.

• BE球による1.2mm連続波のフィット

3.1.3. IRAM 30m+PdBI

In Figure 4 we show the moment-zero map of the merged IRAM
30m and PdBI data (see Section 2.3), overlapped with IRAM
30m MAMBO-II map of the dust continuum emission at 1.2mm. The peak is 1 Jy beam−1 km s−1 and the arc structure hinted
at the column-density single-dish map (panel (b) of Fig.1) is now
clearly seen.
3.2. Chemical survey (FTS)• ARTISTによる放射輸送計算• Tdust=Tgas, no velocity field• 分子分布を再現するには~8000au,14500auでアバンダンスを変化させる必要がある• 多くの分子はコア中心でアバンダンス低=>コア中心でダストに吸着• アバンダンス変化の半径はgrain growthの半径[Forbrich+2015]とconsistent• 分子分布の非対称性• C4H, HCO+,CH3OHは南東にピーク=>南東からのUV照射による可能性(PDR)• 西~北西側にθ-Oph(B2)がある• 磁場との比較• Alves+2014によるpol. dataと比較• 南西側で偏光度が高い=>radiative torqueによるダスト整列ならFUV
照射とconsistent• コア中心で偏光度↓もradiative torque的A&A proofs: manuscript no. Juarez_et_al_2016