FUGINでみる銀河系における分子雲分布
Location of molecular clouds in the galaxy using FUGIN

Hiro Saito（南極）# 00 Aims
- Establishment of method of molecular cloud identification- Calculation of basic physical parameters of molecular clouds- Reveal inner-structures of molecular clouds- Identify far distant clouds- Reveal size function and mass function of molecular clouds- Distribution of clouds in the galaxy

Verification of Identification method
Identification Method using the results of Dendrogram* Dendrogram : treat as a tree that represents the hierarchy ofthe structures

# 00 Aims
- Establishment of method of molecular cloud identification- Calculation of basic physical parameters of molecular clouds- Reveal inner-structures of molecular clouds- Identify far distant clouds- Reveal size function and mass function of molecular clouds- Distribution of clouds in the galaxy

# 01 Introduction- FUGIN survey* FUGIN : NRO45m + FOREST
NRO 45m : High spacial resolution (~ 15” @ 12CO)
0.2 pc @ 2.0 kpc (sagittarius arm)—> detectable inner structures in clouds

FOREST : detect multi lines simultaneously
12

CO : detect the structure with low column density

13CO : detect the inner structure in the clouds

C18O : detect the dense gas in the clouds

# 01 About FUGIN
Survey Strategy- Area : the first quadrant (10d < L < 50d ; -1.0 < b < 1.0)
the third quadrant (198d < L < 236d ; -1.0 < b < 1.0)
- Line : 12CO, 13CO, C18O
- effective velocity resolution : 1.0 km/s @ 3 mm
- effective angular resolution : 20” @ 12CO
- final map* l,b grid = 8”.5, velocity grid = 0.65 km/s
velocity range = -100 km/s < v < 200 km/s
Noise level : 0.8 - 2.7 K @ dV = 1.3 km/s (12CO)

# 02 Results of FUGIN data
FUGIN : 12CO (R) & 13CO (G) & C18O (B) : NAOJ

M16
20

W39/RCW188

16W33

1210

M1710

Spitzer : 24um (R) & 8um (G) & 5.8um (B) : NASA# 03 Molecular Cloud Identification
Structure Identification using the results of Dendrogram

leaf1

leaf2
branchleaf3
trunkDendrogram can identify the structures with various scales at the same time—> We can identify the molecular cloud as well as the internal structures

# 04 Molecular Cloud Identification< Cloud candidates >- select separate velocity- final identified structures : 93799- Physical parameters of Trunks
dV = 1.0 - 18.3 km/s, R(“) = 19.8 - 2190” , N(H2) = 3.8x1022 - 3.4x1027 cm-2
45000

1.4 10dV（km/s）R（”）

4

1.2 104000

41 103000

N

N

8000

6000

2000

4000
1000
2000

0
0

0.5

1log(km/s)

1.5

0
1

1.5

2

2.5

log(R")

33.5

Molecular Cloud Identification- final identified structures : 93799- Physical parameters of Trunks
dV = 1.0 - 18.3 km/s, R(“) = 19.8 - 2190” , N(H2) = 3.8x1022 - 3.4x1027 cm-2

< Example of Identified Structures ># 05 Distance of Molecular Structures< Decision of Distance >- Using kinetic distance estimated using
1154 the LSR velocity

ROMAN-DUVAL- Near / Far distance problem

Check - The different of parameters between
the distant clouds and the local clouds

Figure 1. Sketch of the HISA method to resolve the KDA. In the inner Galaxy, a sincorresponds to two distances along the line of sight, a near (in blue) and a far (in red) kin
radial velocity Vr , which is the projection of the orbital velocity V0 of a cloud around theis parallel to the line of sight. In this case, the radial velocity is maximal and the nearlocated at the near kinematic distance absorbs the 21 cm radiation emitted by a warm H itoward a near cloud exhibits an absorption line that is coincident with a 13 CO emission la warm H i background emitting at the same velocity as that of the cloud. Therefore, ther# 05 Distance of Molecular Structures< Decision of Distance >- Using kinetic distance estimated using
1154 the LSR velocity

ROMAN-DUVAL- Near / Far distance problem

Check - The different of parameters between

W3Faularr

mRiar Carin a Armerseu+260s

A

Velar+240m

CMa
OB1 Maddalena’s
Mon Gem
Cloud
OB1 OB1Carina
Tangentng

S147+220+200Centaurus
Tangentnding
Arm

60°

Apr
O u t exm
A r

120°ecPE

180°

Aquila RiftCyg XCas Ae rs e u solc−100P

W44p

S235

W51W50Nuclear

S147

Cyg
Lindblad Ring & Local Arm OB7DiskM

k0+280ScutumTangent
Sagittarius
Tangent+1003

LSR radial velocity ( km s −1 )the distant clouds and the local clouds

+180

Norma
Tangent

0°
Galactic Longitude

300°

240°

180°

+160+140+140
Resolution

LSR radial velocity ( km s −1 )+120+120+100+100+80+80+60+60+40+40+20+20

0

0

−20

−20

−40

−40

−60

−60

−80

−80

−100

−100−120−120−140180°

170°

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120°

110°
Galactic Longitude

100°

90°

80°

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40°
−160320°300°

290°280°

270°

260°

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240°

230°

220°

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190°

180°

−140

Galactic Longitude−180−200−220

Figure 1. Sketch of the HISA method to resolve the KDA. In the inner Galaxy, a sincorresponds to two distances along the line of sight, a near (in blue) and a far (in red) kin
radial velocity Vr , which is∫ the projection of the orbital velocity V0 of a cloud around theis parallel to the line of sight. In this case, the radial velocity is maximal and the nearlocated at the near kinematic distance absorbs the 21 cm radiation emitted by a warm H itoward a near cloud exhibits an absorption line that is coincident with a 13 CO emission la warm H i background emitting at the same velocity as that of the cloud. Therefore, ther
−1.5

−1.0

−0.5log

−240
−260

310°

30°

20°

10°

0°

350°

340°

330°

0.0

Tmb db (K arcdeg)

0.5

1.0

FIG. 3.—Longitude-velocity map of CO emission integrated over a strip ~4° wide in latitude
centered on the Galactic plane (see §2.2)—a latitude range adequate to include essentially allemission beyond the Local spiral arm (i.e., at |v| > 20 km s–1). The map has been smoothedin velocity to a resolution of 2 km s–1 and in longitude to a resolution of 12´. The sensitivity
varies somewhat over the map, since each component survey was integrated individuallyusing moment masking at the 3-σ level (see §2.2).

100

1localfar# 05 Distance of Molecular Structures
80

0.5log(dV)

60

NCheck - The different of the parameters between
400

the distant clouds and the local clouds-0.5

20dV01

1

1.5

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2.5

-1

3.5log(R("))

50

100
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31far

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2.53local
far

far

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0.5local
far

N

N

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80 20
800

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II/S- dV
dV-R

180

30

1.5log(R)100

log(dV)

0.8

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600

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0
0

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11NN

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log(R("))

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local

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local

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20200 300

00.2

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2
0.4

log(dV)

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log(R("))
log(R("))
0.8
10.6

120-10

3.5
3.5
1.5

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33

3.5

1023

2.5 4

30

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1011.520012.550

20II(total)/S33200

1.5log(R)

10N

N
0-0.2

1.5
1.5-1-0.5

400

00 100
1130

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112log(dV)

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1.5log(dV)
II(total)/S-0.5

03.5

123dVlog(R("))

1000

50800

40log(R)dV

4563 5

3.56# 05 Distance of Molecular Structures
1154

ROMAN-DUVAL< Near/Far Check list>- Average I.I. (Average Intensity)- Virial ratio- hight of the structures- distribution of Arm in L-V diagram- (Image : distribution of intensity)

Figure 1. Sketch of the HISA method to resolve the KDA. In the inner Galaxy, a sincorresponds to two distances along the line of sight, a near (in blue) and a far (in red) kin
radial velocity Vr , which is the projection of the orbital velocity V0 of a cloud around theis parallel to the line of sight. In this case, the radial velocity is maximal and the nearlocated at the near kinematic distance absorbs the 21 cm radiation emitted by a warm H itoward a near cloud exhibits an absorption line that is coincident with a 13 CO emission la warm H i background emitting at the same velocity as that of the cloud. Therefore, ther# 05 Physical Parameters of Molecular Structures< Molecular Clouds >- Physical parameters of Trunks
dV = 1.0 - 18.3 km/s, R(pc) = 0.03 - 72.4 pc, M(Mo) = 0.1 - 3.0x106 Mo
線幅（km/s）

半径（pc）

質量（Mo）

45000

4 10
1.4

8000

1 10

1.2 1044

1.2 107000

1 104000
6000

48000
4

1 108000

6000

N

4000

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NN

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000-1-0.50.5 00.5log(km/s)
log(dV(km/s))

11

1.51.500-201-1.5-11.5 -0.5

200.5 2.51log(R")
log(R (pc))

1.5 3

23.5-202log(Mc(Mo))

46

# 05 Physical Parameters of Molecular Structures< Relation of Physical Prameters >dV vs R

Mv vs Mc

Mv/Mc vs R

銀河系内における分子雲の分布
・比較的サイズが大質量の構造で調査（Mc > a few x 103 Mo）
・銀河系内域（Rg < 7 kpc)—> 2450個の分子雲で調査
線幅（km/s）

半径（pc）

300

質量（Mo）

400

350

350

250

300

300
250

200

250200NN

N

200

150

150

150

100

1001005050000.51log(dV(km/s))

1.50-0.5

5000.51log(R(pc))

1.52023456log(Mc(Mo))

物理量：dV = 1.4 ~ 14.9 km/s, R = 0.8 ~ 72 pc, Mc = 1000 ~ 3.0 x 106 Mo

7

銀河系内における分子雲の分布
・銀河中心座標系に分子雲配置・質量ごとに分布を調査—>

GMCは渦状腕内に存在すると期待腕間にどの程度の質量の分子雲が存在するか

61616sagittarius> 1.0 x 105 Mo

6Mc > 10 Mo

412125Mc > 5 x 10 Mo> 1.0 x 104 Mo

5Mc > 1.0 x 10 Mo

scutum884Mc > 1.0 x 10 Mo0norma-8500-4-4-6-4-20

X[kpc]

2461616121244

McMc>>1.0
1.0xx1010Mo
Mo00

norma-2-2-6-6-8-8

scutum

W43-4-4M17-855Mc>>55xx1010MoMc
Mo
5Mc>>1.0
1.0xx1010Mo
McMo

W33

W51

-6Mc>>10106 Mo
Mo
Mc

44

22

W43-4

sagittarius
644

Y[kpc]
Y[kpc]
Y[kpc]
Y[kpc]-2Y(kpc)

66

F

Y[kpc]
Y[kpc]

2× > 5.0 x 102 Mo-8-8 -8-888W33

W51

M17-6-6-4-444X(kpc)
E-2-20000X[kpc]X[kpc]

2244-4-466-8-8< 結果 >銀河系内の分子雲分布調査- 103 Mo以上の分子雲（2450個）について調査- 105 Mo以上の分子雲は概ね腕状に分布
sagittarius, scutum, norma腕を確認- 腕間領域には104 Mo以上の分子雲はほとんど存在しない
たたし、sagittarius-scutum腕間の一部に104 Mo程度の分子雲が存在

渦状腕ごとの相違- scutum腕とnorma腕では有意義な違いは見られない- sagittarius腕は線幅、質量が小さい（？）