THE STAR FORMATIONNEWSLETTER
No. 271 (#11-15)
塚越崇(茨城大)
31 Jul. 2015

1. Herschel observations of EXtra-Ordinary Sources: Analysis of theHIFI 1.2 THz Wide Spectral Survey Toward Orion KL II. ChemicalImplications
2. Bipolar HII regions - Morphology and star formation in their vicinity
I - G319.88+00.79 and G010.32-00.15
3. Volatile depletion in the TW Hydrae disk atmosphere
4. Star formation scales and efficiency in Galactic spiral arms
5. The distribution of deuterated formaldehyde within Orion-KL

– 26THz–Herschel observations of EXtra-Ordinary Sources: Analysis of the HIFI 1.2
Wide Spectral
Survey Toward Orion KL II. Chemical Implications
N.R. Crockett et al.

• ホットコアのcomplex mol.の生成過程について調査• Orion KL•

ホットコア

•

compact ridge•

plateau (outflow)• Herschel/HIFI HEXOS program•

Crockett+2014(Paper1)のラインサーベ
イ結果を使用•

分解能11-44”•

complex mol.に着目した解析•

XCLASSによるモデリング• Hot core•

5つのcomplex mol.

••

CNを含むものはhighly excited

シンプルなCN系分子もhighly excited• compact ridge•

hot coreと似た傾向•

N系がhighly excited• plateau•

CH3CNが唯一のhighly excited spectrum• S+O系の分子もhottest gasのトレーサーかも• OSU gas-chemicalコードを使用して化学モデリング• 物理構造進化は追わない•

コードの確認とN系分子の傾向と再現に着目• 二つのphaseでアバンダンス進化を計算•

isothermal collapse••

10K, 1Myrwarm-up phase•

温度がtwarmで上昇し最終温度TF•

twarmとTFを変えて計算– 29 –

• N系分子は高温をトレース(Oより)•

N系はダストから蒸発しづらい••

N,Oの比較はTexの高分解能観測が必要

ガスフェーズ反応でhighly excited cyanideを作る•

高温でCH3CN等を生成するモデルあり[Rodgers&Charnley2001など]• S+Oも高温をトレース•

H2S生成(ダスト上Bipolar HII regions - Morphology and star formation in their vicinity I - G319.88+00.79 andG010.32-00.15
L. Deharveng, et al.

Fig. 1. Formation of a bipolar H ii region, according to the simulation of Bodenheimer et al. (1979; their figure 4; the thickness of the parental planeis 1.3 pc, its density 300 H2 cm 3 ). The ionized material appears in red, the neutral material in blue; the density of the material is indicated by thesaturation level. Schema a shows the dense molecular plane surrounded by low density material, the initial Strömgren sphere around its central
exciting star (T⇤ =4⇥104 K). In schema b, at 3⇥104 yrs, the expanding H ii region reaches the border of the parental cloud, and the low density
material is quickly ionized; a bipolar nebula forms. In schema c, at 1⇥105 yrs, the high density ionized material flows away from the central region;
high density molecular material accumulates at the waist of the bipolar nebula, forming a torus of compressed material.

• ISMフィラメントで見られるHII bipolar nebula(バブル構造)の探査•

シリーズ物の紹介論文•検出された16個のうち二つの領域に着目• 使用する観測データ•

理論計算の予想[Fukuda&Hanawa2000]

Fig. 2. Star formation triggered by the expansion of an H ii region close to a filament, according to the simulation of Fukuda & Hanawa (2000;their figure 1; model C1l’: neutral sound speed 0.3 km s 1 , maximum density on the axis of the filament 2⇥106 cm 3 , exciting star at 0.025 pc
of the filament’s axis). The neutral filament appears in grey, the ionized gas in pink; we show what we believe to be the extent of the ionized gas
in the plane containing the axis of the filament and the exciting star (black cross) of the H ii region. Schema a shows the expanding H ii region(age 8.5⇥104 yr) pinching the molecular filament. In schema b, first-generation cores have formed by compression of the neutral material by theL. Deharveng et al.
ionized gas (age 2.1⇥105 yr). In schema c, second-generation cores have formed due to gravity (age 3.0⇥105 yr). The first- and second-generation
cores are separated by 0.1 pc.

DSS, Spitzer GLIMPSE, Herschel Hi-GAL, 2MASS, MALT90• シミュレーションを元に見えうる構造を予想•dense filament•HII region - filamentに垂直

last case. Figure 3 shows that the 8.0 µm bubbles enclose twoseparate H ii regions: we clearly see two separate zones of extended 24 µm emission at the centre of each bubbles. In bipolar
H ii regions like Sh 201 (see below), the extended 24 µm emission comes from the central region, the region where the lobes
originate. Furthermore, the Herschel-SPIRE maps show no cold
filament between N10 and N11.
The H ii region Sh 201 is a textbook example of a bipolar
H ii region (Fig. 3). It has been studied using deep Herschelobservations (see Appendix C of Deharveng et al. 2012). Thecomplex displays a cold filament observed at SPIRE wavelengths, an H ii region centred on this filament, and two lobes,
well traced at 8.0 µm (Fig. 3), perpendicular to the filament.
The ionized region is bright in its central part. It shows a narrow
waist, limited on each side by two massive clumps. YSOs ofClass 0 and Class I are observed in the direction of these clumps•HII regionの励起星•bipolar nebularによってはかれたdense material4

良い観測結果例(Deharveng et al. 2012).
In all the figures of this paper the regions are presented in
Galactic coordinates.

4. Reduction methods
4.1. Determination of the physical parameters of thefilaments and clumps

For all estimates in this paper, we assume a gas-to-dust ratioof 100. We assume the following values for the dust opacity⌫ , 35.2, 14.4, 7.3, and 3.6 cm2 g 1 , respectively, at 160, 250,

• Reduction methodの紹介•Tdust、柱密度および質量の導出 - Herschel•clumpの速度構造 - MALT90の分子輝線•YSO同定 - Spitzerのcolor-colorおよびαL. Deharveng et al.: Bipolar nebulae• G319.88-00.79の結果の紹介•

bipolar成分がIRで見え、それに垂直にフィラメントが伸びる•

中心付近ではリング状分布••

手前側の減光が大きい

Fig. 4.
posed
et al. 2
dicatedSpitzer
for therespect
red, grand 4.5
mic unappear
ionizedTdustはフィラメントでcold(13.6K)、HIIバブル付近で23.2K•

N(H2)マップで3つのclump•

YSOの同定 - #4-9は付随するYSO

5.2. The exciting cluster - The distance of the complex

A cluster is present in the central region (Fig. 5), visible in theof 2.45 kpc. 2) Figure 5 sis double, composed of tw
2MASS magnitudes are thusL. Deharveng et al.: Bipolar nebulae

L. Deharveng et al.: Bipolar nebulae

h – in red, green,
MASS emission,as (linear units).
S, in red, green,contours are proJy/sr by steps ofm of the 250 µm

Fig. 6. Centre of G319.88

Fig. 7. Temperature and column density maps of G319.88+00.79. The left side of the figure concerns the dust temperature. (a) The underly
grey image is the temperature map; the red contours correspond to temperatures of 19, 20, 21, and 22 K; the blue ones to temperatures of 14,00L. Deharveng et al.: Bipol• IRDCとの関連•観測領域でIDされてるIRDCは必ずしも高密度領域にない• global morphology•

南側の手前にcoldなガスが存在->リングの下側の吸収を説明•

Herschelでは受からない希薄成分

Fig. 27. Morphology of G319.88+00.79. The ionized material appears
in pink, the neutral one in blue. We do not know the extent of the molecmaterial
at the back of the nebula.
L. Deharveng et al.:ularBipolar
nebulae• triggered star formation•

G319.88はless active SF•とはいえ、#4,#5はionization front(brightrim)に存在しており(C1,C2 clump)、triggered star formationの可能性がある•Fig. 27. Morphology of G319.88+00.79. The ionized material appears
G010.32のほうがactiveなtriggered
starin pink, the neutral one in blue. We do not know the extent of the molecular material at the back of the nebula.

formation

central region in the direction of the bottom lobe. This velocity

central region in the direction of the bottom lobe. This velocity
gradient indicates an approching bottom lobe with respect to thecentral region, and a receding upper one (thus Fig. 28).
The parental filament (left of the H ii region) is seen in absorption, and in line with it, the C1 and the C4 + C5 external
clumps are also seen in absorption at Spitzer-IRAC wavelengths.
Thus these clumps are slightly in front of the H ii region. The C2and C3 clumps are not clearly seen in absorption, but they arebordered by bright rims (PAH emission) on their side turned towards the exciting star (Fig. 16); thus they lie in front of theionized region and its exciting star15 . This suggests that the C1to C5 clumps form a single structure, half a torus of dense material, encircling the waist of the bipolar H ii region and located infront of this region.
The H ii region is not open on its back side (it is ionizationFig.
28. Morphology
00.15 complex.
The planeclosingreprebounded),as we seeofa thefaintG010.32
Spitzer-IRAC
PAHs emission
sentedhere
contains
theparentalfilament,
theclumps
atthewaistof thethe clumpy torus on its back side. The parental structure is much
nebula,andtheexciting
star.
Thelineofsight
makes
asmallangle
withmore dense on the front side of the H ii region than on the backthis plane.
one. We suggest that the parental structure was a flat 2D cloudpresenting a strong density gradient or containing a dense pre-Fig. 28
sentednebula
this plW
massi
ing dsigna•
the iofragm
shapeized ggas trzones•
youngMYSconta
high atains
metha(2010Volatile depletion in the TW Hydrae disk atmosphere
Fujun Du et al.

• TWHya円盤のガス質量の差異•~0.005M⦿ (CO等)

考えて解釈する• C/Oの主な担い手• 円盤構造を与えてシミュレーション•

thermo-chemical + radiative transfer code
[Du&Bergin+2014]•

温度構造を計算し静水圧平衡を仮定•

C/Oのabundanceを変化させる

ngas (cm 3)

5 10 15 20

0200>0.05M⦿ (HD [Bergin+2013])• 円盤表層からCOやH2Oが減少したと(a)
10150 8642100 0050z (AU)•z (AU)

200(b)
Tgas (K)10150 8642100 0
0 5 10 15 20

1014
1013
1012
1011
1010
109
108
107
106
105
104(c)
10864200

X [O]

10 3
10 4
10 5
10 6
10 7
10 8
10 9
10 10
10 11

5 10 15 20(d)X [C]10864200 5 10 15 20103

100

10 310 410 510 610 7
10 8
10 910 10
10 11500050

100r (AU)15010200050100r (AU)150200Fig. 1.— Distribution of disk physical parameters
used in the models. (a): gas density distribution
in the two models. (b): gas temperature distribution in the model in which the oxygen and carbon abundances are changed; for the model withfull oxygen and carbon abundances, the gas temperature distribution is slightly di↵erent due tochanges in the heating and cooling rates of oxygenand carbon- bearing species. (c) and (d): distribution of oxygen and carbon abundances relative tohydrogen nuclei in the model in which their abundances are changed.

• high-J/回転振動COを説明する
為、snowlineに向けてabundanceを徐々に増やす• J-10-9,23-22のCOの説明には、10AUより内側でISMx10のabundanceが必要

Fig. 2.— Ratios between the modeled and observed intensities for a selection of lines. Red dot: with fulloxygen and carbon abundances; blue rectangle: with depleted oxygen and carbon abundances. The arrows
mean that the observed values are upper limits. The relative measurement error of the observational data
is usually much less than 50%. For the detected lines, a perfect fit would land on the dashed line.

=>full modelよりも観測を良く再現• 表層でのC/O depletionの要因 =>ダストへの吸着と沈殿••

成長/沈殿によりUV desorption/dissociationを逃れる
TWHyaはturbulenceが弱くmixing起きにくい• ダストはmigrationによって内側へ•

内側でのabundance上昇•

C/O richな微惑星

4Star formation scales and efficiency in Galactic spiral arms
orm D.J. Eden et al.
ABSTRACTWe positionally match a sample of infrared-selected young stellar objects (YSOs), identified by combining the Spitzer GLIMPSE, WISE and Herschel Space Observatory Hi-GAL
surveys, to the dense clumps identified in the millimetre continuum by the Bolocam Galactic
Plane Survey in two Galactic lines of sight centred towards l = 30◦ and l = 40◦ . We calculate the ratio of infrared luminosity, LIR , to the mass of the clump, Mclump, in a variety of
Galactic environments and find it to be somewhat enhanced in spiral arms compared to theinterarm regions when averaged over kiloparsec scales. We find no compelling evidence thatthese changes are due to the mechanical influence of the spiral arm on the star-formation
efficiency rather than, e.g., different gradients in the star-formation rate due to patchy or intermittent star formation, or local variations that are not averaged out due to small source
samples. The largest variation in LIR /Mclump is found in individual clump values, which follow a log-normal distribution and have a range of over three orders of magnitude. This spreadis intrinsic as no dependence of LIR /Mclump with Mclump was found. No difference wasfound in the luminosity distribution of sources in the arm and interarm samples and a strong
linear correlation was found between LIR and Mclump.
Key words:
stars: formation – Galaxy: structure – infrared: ISM – radio continuum: ISM

The distribution of deuterated formaldehyde within Orion-KLC. Favre et al.

• Orion KLのD化物の調査

SMA連続波マップ• hot coreの初期低温状態の情報• 分子毎にD/H比が異なる• Herschel HEXOS key programの発展でSMAの観測を行う• H2CO,HDCOに着目• grain surface reaction:メタノール生成仮定の中間• warm (50K) gas-phase reaction: CH2D+から生成される• SMA観測••

Fig. 1.— Continuum emission maps obtained at 213 GHz (grey scale, USB band) andLSB band) toward Orion–KL as measured with the SMA. The first contour and the l(where 1σ=0.132 Jy beam−1 ). The synthesized beams are 3.2′′ × 2.8′′ (P.A. = 26.7◦ ) an= 32.7◦ ) at 207 GHz and 198 GHz, respectively. Blue crosses mark the positions of the fosources derived from Gaussian fits in the (u, v) plane (198 GHz dataset, LSB band). Th
空間分解能~3”、速度分解能~1.2km/s
Hot core (αJ2000 = 05h 35m 14.s 537, δJ2000 = -05◦ 22′ 31.′′ 600), the Compact Ridge (αJ200
δJ2000 = -05◦22′ 36.′′ 462), the North Compact Ridge (αJ2000 = 05h 35m 14.s 144, δJ2000 =13
HDCOの2輝線、paraH2 COの2輝線を観測
the South Compact Ridge (αJ2000 = 05h 35m 14.s 019, δJ2000 = -05◦ 22′ 44.′′ 212).

• 4つのHDCOピークを検出•

dF4以外はH213COも付随• D化メタノールと分布の違いがある• optically thin, LTEを仮定して、Texと柱密度およびD/Hを導出• Texはhot coreで大きい• D/Hは南側のridgeで大きい• D/H比はメタノールより一桁大きい• ホルムアルデヒド放射の起源と生成• OrionBarとH2CO/CH3OHを比較->数桁小さく光解離によるH2CO形成はメインではない• ホルムアルデヒド-メタノールでのD/H比の違い• ダスト表面反応であれば同程度になるはずだが観測結果は違う• hot gas-phase deuterium chemistry in colder gas• 70-100K程度でCH3++HD <-> CH2D+H2+ΔEがactiveに• coldなガス内でホルムアルデヒドが生成される (D化物の増加)