SFN #344 7-11

担当：土井 聖明 (総研大M2)
7. A survey for variable young stars with small telescopes: IV ! Rotation Periods of YSOs
in IC5070
8. CRAFT (Cosmic Ray Acceleration From Turbulence) in Molecular Clouds
9. Touching the Stars: Using High-Resolution 3D Printing to Visualize Stellar Nurseries
10. Dark cloud-type chemistry in PDRs with moderate UV Field
11. The !rst interferometric survey in the K-band of massive YSOs. On the hot dust,
ionised gas, and binarity at au scales

10
2

c

3

2

2

G  50NC2 H /NCH3 OH

G ⇡ 20

3

c

3

2

30

PDRでのchemistryに関する論文・PDRでの炭素関連の輝線観測を行なった・対象：S235←中程度のUV強度 (G~50)

・C2H、C3H2はクランプの縁で最大(C3H2はもう一箇所多いところもあった)
・メタノールはG~20-30のところで最大←ダストからの脱離・組成の比率はPerseusのhot corinoぐらい（Orion馬頭星雲とは違う）↑イオン分子反応とダスト表面反応が中心・PDRのchemistryは以前の分子雲での状態を引き継ぐµイントロ：UVとケミストリー
PDRでは豊富な化学進化が起きる
COMsの形成

主に低温で進行すると考えられていたが、高温環境でも見つかっている

これまではOrion horsehead、Orion Bar PDRが↑G=100↑G=10^4~10^5

調べられて、UVの影響が議論されてきた。
UV強度が中程度の領域を調べる

PDRの概念図。天文学辞典より

観測対象：S235
2

Dark cloud-type chemistry in PDRs

3

M. S. Kirsanova et al.

covering a broader range of ⌧ and = in order to understand the formation and survival of molecules in the irradiated gas. The first aimof this study is to specify which kind of the desorption processes
prevails in the PDRs with moderate UV field. The second aim ofour study is to explore whether the enhanced abundances of smallhydrocarbons are common for the PDRs with moderate UV field.
To achieve these science goals, we explore molecular abundancesin the three PDRs with moderate UV fields against those found in
Horsehead, focusing on precursors of COMs (H2 CO and CH3 OH)
and long carbon chains (C2 H and C3 H2 ). We obtain spatial distributions of their abundances, covering a wide area around the sourcesof the UV emission and away from them, providing a benchmark fora detailed comparison with astrochemical models in the future.

Figure 1. The 3.6 `m Spitzer image of the S235 (left) andABC (right) regions(Fazio & Megeath 2004). White contours show 1.4 GHz continuum emission
2 S235TARGETREGIONS
from NVSS survey (Condon et al. 1998) at 0.01, 0.5 and 0.1 Jy/beam. Names of the H regions as well as dense molecular clumps with the embedded youngstellar clusters are given in bold face in white boxes. Black contours show levels of hydrogen column density: 1, 2, 3 and 4 · 1022 cm 2 based on CO observations
Weregionsselected
irradiatedmolecular
cloudsborderingthesources:
extended
H2
by Bieging et al. (2016). The ionizing sources of the H
are shownby the red stars.
Red diamonds
show otherbright infrared
IRS 1, IRS(Evans & Blair 1981), S235 B⇤ (Boley et al. 2009) andregion
S235 A-2⇤Sh2-235(Kirsanova et (S235
al. 2020a).hereafter,
Black dashed line
show the area
mapped andby IRAM
telescope.
Sharpless1959)
the30-mtwocom-pact H regions S235 A and S235 C (Israel & Felli 1978). The re4.2 Archival data
andgiant
this line
serves as ancloudapproximate
density indicator.
gions belong to the2015),
same
molecular
G174+2.5,
studiedThein
左図：extended
HII
regionが1つ
effective
excitation density is consistent with gas number densities
13
CO emission
We use maps of CO and CO emission from Bieging
et al. (2016)lines by Evans & Blair (1981); Heyer et al. (1996); Kirdetermined by Kirsanova et al. (2014) using ammonia inverse transiand pre-calculated gas column density on the basis
of
these
data
sanova et al.HII(2008);
Biegingal. (2016);
al. (2016).
tions.
Bearing etin mindmoderate Ladeyschikov
optical depth of theetammonialines,
右図：compact
regionが2つfrom Kirsanova et al. (2020a). The spatial resolution of that data is
we expectactualgasaccording
number density
the studiedcan
The distance to S235
A isthat
1.56
kpc
tointhemaserregions
parallax
00

IRAM 30mで以下の分子を観測
MoleculeFrequency
(GHz)

%⌫,
(00 )

3res
(km s 1 )

rms
(K)

)sys
(K)

CH3 OH
c-C3 H2
C2 H
HCN
H2 CO
CH3 OH
CH3 OH
c-C3 H2

84.5
85.3
87.3
88.6
140.8
143.9
145.1
145.1

29.3
29.0
28.3
27.9
17.6
17.2
17.0
17.0

0.18
0.18
0.17
0.17
0.11
0.10
0.10
0.10

0.04
0.04
0.05
0.04
0.13
0.12
0.12
0.12

105
105
96
96
156
164
164
164

Table 1. Observation parameters.

reference positions via frequency switching observations. The ch
sen reference position (J2000 U=05h 41m 18.663s , X=+36 01 0 20.93
was proved to have no contamination of any of the observed lin
down to the rms of 0.05-0.1 K in the units of the antenna tem
perature )A , which is sufficient for the sensitivity of our data. W
used the FTS 50 backend with the spectral resolution of 50 kH
the corresponding velocity resolutions were '0.17 for the 3 mm an'0.10 km s 1 for the 2 mm bands. The beam sizes were '28 00 f
the 3 mm and '17 00 for the 2 mm bands. The system temperatur

結果：強度map
Dark cloud-type chemistry in PDRs

7

Figure 3. Integrated intensities of the detected lines in S235 (left panels) and S235 ABC observed area (right panels). The telescope beam is shown by whitecircle. Pixel size corresponds to one third of the beam size. The colorscale begins at the 3f level for each transition. White contours show levels of hydrogencolumn density: 1, 2, 3 and 4 · 1022 cm 2 based on the CO observations by Bieging et al. (2016). Mm-continuum emission from Klein et al. (2005) is shownby the white contours on the H2 CO and CH3 OH 3
2 emission maps. The ionizing sources are shown by the red stars. Red diamonds show three brightinfrared sources: IRS1, IRS2 (Evans & Blair 1981) and S235 B⇤ (Boley et al. 2009

結果：分子間、UV強度の関係

Dark cloud-type chemistry in PDRs

1013

1012
1012
1013
Nc-C3H2 (cm-2)

1014

G=40~50で最大になって大体一定

1013

1011

1015

1015

1014

1014

NH2CO (cm-2)

NH2CO (cm-2)

G<30ではUVの増加に伴ってhydrocarbonは増加

1012

1011

1013

1012

C3H2 / C2H について

1014
NC2H (cm-2)

NC2H (cm-2)

1014

11

y=10x
y=x
y=0.1x
1013

1014

1014

CH3OH / H2CO について

幅広い範囲(UV強度、CH3OH強度)で、H2COは同じような値
CH3OHはG=20~30で最大

全体的に H2CO < CH3OH なのはdark cloud chemistryと整合的

1013

1012

1015

1012
1013
Nc-C3H2 (cm-2)

y=10x
y=x
y=0.1x1013

NCH3OH (cm-2)

1014

1015

NCH3OH (cm-2)

C2H / CH3OH について

C2HはS235ではほぼ一定だが、S235Aでは幅広く分布↑強度の強いところしか受かってないから(?)
比はOrionの観測より遥かに(25倍)小さい1014
NC2H (cm-2)

NC2H (cm-2)

1014

1013

y=10x
y=x
y=0.1x

1012
1013

1014
NCH3OH (cm-2)

1015

dark cloud chemistryでダスト表面でメタノール形成が起きてる(>10^5 yr)

1013

y=10x
y=x
y=0.1x

1012
1013

1014
NCH3OH (cm-2)

1015

イントロ：cosmic rayの重要性、イオン化率
分子雲内での化学反応はcosmic rayが出発点
cosmic rayによるイオン化率は観測から10^-17 < ζ < 10^-15ぐらいと見積もられている（外部からcosmic rayがやってくるとすると）分子雲の内側は遮蔽されてしまうのでもっと低くなる→その場でのcosmic rayの生成

これまでの案：protostellar jet, accretion shock, HII region, stellar windなど（どれも局所的）本研究：乱流によるcosmic ray生成・乱流のエネルギーが粒子加速に使われる
・一様なcosmic rayを生成

主に、エネルギーの観点から十分かどうかの議論を行う。

tons within the reconnection region, Np (E), isis then " = ⇢✏. A fraction of this energy, fCR
goes into CR acceleration,
such
Gaches etal. that
手法（仮定）"CR = fCR ",

大事な式

(7)

dE
Np (E) =dt

where we take fCR = 0.01 as an estimated lower
limit of the acceleration efficiency. We assume
particles are accelerated within the turbulent reconnection regions via a first-order Fermi process (de Gouveia dal Pino & Lazarian 2005b).
Following Khiali et al. (2015), the CRs are
isotropically injected with an exponentially suppressed power law
Q(E) = Q0 E

e

E
E0

消失

1 Z Emax
E

Q(E)dE(10)

注入where dE
is calculated using a prescribed loss
dtfunction, L(E)(8)

dE
= M2s nvCR (E)L(E)
dt

(11)

where we take = 2 and E0 = 10 GeV3 . Increasing E0 negligibly impacts our main results,
due to the weak dependence of the CRIR on
super-GeV CRs. Further, changing between
and Ms is the
sonic
Mach
number,M=spasic schematicoftheproposedmechanism.
Top
left:
We
assumeapower-law
power
spectrum2 and 3/2 produces no qualitative changes in(l)/cs , ctos an= kb T /µmH , µ is the mean molecline width-size relation. Top right: The turbulence driven at scale, `, corresponds
the results,
nor byquantitative
anthe turbulenceular weightty and magnetic
field “seen”
the turbulence.variations
Bottom right:overWithinthere areand T = 10 K, and vCR (E) is theregions orderof widthof magnitude.
(Eq. 18). Here, The
protonsbounce between thereconnectionrelativistic
fronts. Bottom
normalization
factor,velocity of the CR. We utilize thelting acceleration,
via the Fermi
Q0 , is calculated
bymechanism,
assumingresults in a power-law energy distribution.
loss function given in Padovani et al. (2009).
4
mpirical di↵usion coefficientZ(Lon-ZThe energy-loss scale, or the range, R(E) is
Emax
Turbulent reconnection is an essential part
given by the stopping column, (Padovani et al.
"CR = dV
Q(E)dE(9)of the turbulent cascade (Lazarian & Vishniac
2009)
✓
◆
Emin
E
1999) and a volume-filling process. This induces
Z E= D0
cm2 s 1(12)
10 GeV

dE

2

結果
6

Gaches et al.

・左図：cosmic rayの定常解
ζ~10^-9で大きすぎ→ 分子雲全体で考える
・右：ある距離(l)でのcosmic rayの強度
拡散大でζ大低エネルギーの粒子ほど減衰されやすい

Figure 2. Left: Steady state solution for the flux, jp (E) as a function of energy for di↵erent values of `.
Right: Transported cosmic ray flux, jT (E), as a function of energy for di↵erent values of D0 and `. Notethe di↵erent scales for the x- and y-axis of the subplots. Without including the impact of energy-losses anddi↵usion throughout the cloud, the resulting cosmic-ray flux would produce nonphysically high ionization
rates.
Table 1. Power-Spectrum Averaged Cloud Ionisation Rates
D0 =3 ⇥ 1027

1 ⇥ 1028

3 ⇥ 1028

1 ⇥ 1029

Right: Transported cosmic ray flux, jT (E), as a function of energy for di↵erent values of D0 and `. Notethe di↵erentthe
scalesfor thex- forandthey-axisthe subplots.
Without
includingthetheimpactofofenergy-losses
anddi↵erentscalesx- andofy-axisof the subplots.
Without
including
impactenergy-losses anddi↵usionthe cloud,thethecloud,resultingcosmic-ray
flux would
producenonphysically
結果 throughout
di↵usion throughout
the resulting
cosmic-ray
flux would
producenonphysicallyhighhigh ionization
ionization
rates.
rates.
他の乱流モデルの場合
1. Power-Spectrum
AveragedCloud
CloudIonisation
Ionisation Rates
TableTable
1. Power-Spectrum
Averaged
Rates

D0 =

D0 =

3 ⇥271027

3 ⇥ 1028
1 ⇥ 1028

1 ⇥ 1028
3 ⇥ 1028

3 ⇥ 10

Fiducial#
9.1( 19) 7.5( 17)
Fiducial
#
9.1(
19)
7.5(
17)
Less Bound#
2.8( 18) 2.3( 16)Less Bound#
Strong Turb.
2.9(18)2.8(1.1(18)15) 2.3(
6.2( 16)
14)
StrongTurb. Turb.
2.9( 18)
Kolmogorov# 1.1(
1.1(15)17) 6.2(
1.7( 14)16)

1 ⇥ 102929

1 ⇥ 102.5( 15)2.5(
15)
8.0( 15)8.0( 13)15)
6.7(
6.7( 15)
13)
1.6(

Kolmogorov#
1.1(17) cloud1.7( cosmic-ray16) 1.6(ioniza15)
Note— Turb.
The power-spectrum
averaged
Strongturbulenceではイオン化率が高い

1 ), ⇣ , (Eq. 22) for di↵erent values of D . The
tion
rates
(s
0 ionizaW
Note— The power-spectrum
averagedcloud
cosmic-ray
銀河中心の観測となら合うかも(?)
value in theparenthesis indicates the power. The fiducial model1
tion rates (s ), ⇣W , (Eq. 22) for di↵erent values 1of D0 . The
uses the parameters ↵V = 1, = 0.5, 0 = 1 km s and L = 1
value intheparenthesis
indicatesthepower.
The
fiducial
model
pc. The rest of the rows delineate models with a specific param1 and L = 1
uses theparameters
↵
=
1,
=
0.5,
=
1
km
s
0
V Bound” corresponds
eter variation: “Lessto ↵V = 2, “Strong
1models
pc. ・密度、磁場強度、イオン化率、乱流特性を観測から制限する
The
rest of thetorows
delineatewith a specificparamTurbulence”
=
2.5
km
s
and “Kolmogorov
Turbulence”
V
Figure 3. Left: Cosmic ray ionization rate, ⇣(`),
to= 0.33.
TheBound”# represents
ionizationtorates
below
the raeter
variation:“Lesscorresponds↵=
2,“StrongV
due to turbulent reconnection from turbulenceことでこの機構が正しいのかを判断することができるかも
at
19 .
1
dionuclide
ionization
rate(Adamsetal.
2014),⇣⇡
10
RN Turbulence”
Turbulence”
to V = 2.5 km s and “Kolmogorov
lengthscale,`,
accountingfordi↵usionandenergyFigure 3. Left: Cosmic ray ionization rate, ⇣(`),
・拡散係数の逆算にもなるto= 0.33. The # represents ionization rates below the ralosses.
due to turbulent reconnection from turbulence at

観測と合うのは、D=3x10^28ぐらいのとき

length scale, `, accounting for di↵usion and energy
losses.

dionuclide ionization rate (Adams et al. 2014), ⇣RN ⇡ 10

19 .

9

3次元画像の可視化についての論文

・分子雲は非常に複雑な密度構造を持つ・シミュレーション結果の可視化は難しい
2c・3Dプリンターを使ってわかりやすく可視化

3

2

2

G  503

・これまでわかりにくかった平板上の構造とかもわかりやすく可視化
NC2 H /NCH3 OH

G ⇡ 20

30

c

3

2

Floyd Steinberg dithering

Imara, Forbes & Weaver

でbinaryへ変換
6

Imara, Forbes & Weaver

gure 2. Multi-material additive manufacturing workflow for the production of tangible (physical) models from astronomical
Figure 4. Comparisons of 2D volume renderings of a subset of our simulations (upper row) and their corresponding 3D-printed
ulation data sets. The molecular cloud simulation parameters (A) are used to construct a point cloud-based 3D data set
counterparts (lower row). The dotted circle in each case denotes the border of the cropped spherical volume. From left to right, which is cropped into a spherical volume (denoted by the dotted circle) and sliced into a stack of 8-bit BMP files thatthe fiducial
model, purely solenoidal turbulence, and purely compressive turbulence. For scale, each 3D-printed sphere measure
respond to the x, y, and z resolution of the 3D printing platform (C). The bitmap slice intensity values are normalized
in order8 cm
in diameter.
e↵ectively visualize the features of interest (D) and then, via a di↵usion dithering step, are separated into theircorresponding7⇥3