銀河中心の　 H ３＋

Department of Astronomy and AstrophysicsDepartment of Chemistry and

The Enrico Fermi Institute, The University of Chicago

岡　武史

岡コロキウム　東京工業大学、 2007 年 10 月 19 日

Thomas R. Geballe Gemini Observatory

　後藤　美和　　　　　　　 Max Planck Institute for Astronomy

　臼田　知史　　　　　　　 Subaru Telescope

Benjamin J. McCall University of Illinois, Urbana-Champaign

The eventful 1996

7 月 29 日　 Doppler shift II

八ヶ岳、剣、立山

9 月 25 日　岡コロキウム

7 月 15 日　 Doppler shift I

4 月 29 日　星間 H ３＋検出　

Nature, 384,334

森野米三先生追悼記念講演会

第一回分子研フォラム

The sigh of relief is audible round world of astronomy

1.01

1.00

0.99

0.98

0.97

Rel

ativ

e In

tens

ity

3.6693.6683.667

Wavelength (µm)

3.7173.7163.715

R(1,1)u

R(1,1)lR(1,0)

N(H3+) ~ 3 1014cm-2

111025

214

1415166

175

312229

1827

2619237824

21

Surprise 1: H3+ in diffuse cloud

Cygnus OB2 No 12 HD 183143

1.01

1.00

0.99

0.98

0.97

Rel

ativ

e In

tens

ity

3.7173.7163.7153.6693.6683.667

Wavelength (µm)

R(1,1)u

R(1,1)l

R(1,0)

V = 11.48

V = 6.86

Geballe, McCall, Hinkle, Oka, ApJ 510, 251 (1999) McCall et al. ApJ 567, 391 (2002)

Ubiquitous H3+

Production : Cosmic Ray 0.6 primary particles cm-2s-1

H2 → H2+ + e- ζ n(H2) ζ ~ 3 × 10-17 s-1

H2+ + H2 → H + H3

+ kL n(H2+)n(H2) kL~ 10-9 cm3 s-1

C.R.

Destruction

Dense Clouds (~104 cm-3)

H3+ + CO → H2 + HCO+

Rate = kLn(H3+)n(CO)

kL ~ 10-9 cm3s-1

Diffuse Clouds (~ 102 cm-3)

H3++ e- → H + H + H

Rate = ken(H3+)n(e-)

ke ~ 10-7 cm3s-1

n(H3+) = [ζ/kL][n(H2)/n(CO)] n(H3

+) = [ζ/ke][n(H2)/n(e-)]

10×ζdense ~ ζdiffuse

Storage Ring Measurements

20 ns 45 ns

electron beam

H3+

H, H2

+ Complete vibrational relaxation+ Very simple experiment

+ Control H3+ – e- impact energy

- Rotationally hot ions produced- No rotational cooling in ring

CRYRING

McCall et al, Nature, 2003

Surprise 2 ： Central Molecular Zone

Morris, Serabyn, ARA&A (1996)CMZ

OH, H2CO, CO, CS, NH3, HCN H3+

Mezger, Duschl, Zylka, A&A Rev. (1996)

R(1, 1)u R(1, 0)

Geballe Phil. Trans. RSL A358, 2503 (2000)

is the treasure house of H3+

Telescope and spectrometer

UKIRT 3.8 m CGS4 8 km s-1 Mauna Kea 1982

Subaru 　 8.2 m IRCS 15 km s-1 Mauna Kea 2000

Gemini South 8 m Phoenix 5 km s-1 Cerro Pachon 2003

VLT 8 m CRIRES ≤3 km s-1 Cerro Paranal 2006

Surprise 3: Discovery of metastable H3+

Goto, McCall, Geballe, Usuda,Kobayashi, Terada, OkaPASJ, 54, 951 (2002)

(3, 3) metastable

Subaru telescope

(1, 1) ground level

Spectroscopy

130 pc

100 km s-1

Goto, McCall, Geballe, Usuda, Kobayashi, Terada, Oka PASJ, 54, 951 (2002)

Surprise 4: 　捨て札があれよあれよとすべて生き札となった （水村美苗）

霜田光一　　二重共鳴

Collision

Forbidden transitions

衝突にも選択率がある

分光学の選択率は破れるh

E

ΔK　=　0

Δk　=　± 3

Breaking　

Symmetry　

Interstellar NH3 Oka, Shimizu, Shimizu, Watson, ApJ 165, L15 (1971)

Interstellar H3+ Pan, Oka, ApJ 305, 518 (1986)

Metastable

27.2 days

20.4 days

μ

Critical Density 200 cm-3

Ortho I = 3/2

Para I = 1/2J

KCollision H3

+ + H2 → (H5+)* → H3

+ + H2

16 hrs8 hrs

++ = uuu

The ideal rotational levels of H3+

(3,3)

(2,2)Unstable

(1,1)Ground

361 K

Rate Equations

1' ' ' '2

' '

( ) exp( )2

J K JK JK J KJK JK

J K

g E Ek C

g kT

2

' '' '

' '

' '' '

' '

( )( ) ( )

( ' ') ( )

( ' ') ( )

( ) ( ) ( ) ( )

J K JKJK J K

J K

J K JKJK J K

J K

e XX

dn JKn H f JK

dt

A n J K A n JK

k n J K k n JK

k n e n JK k n X n JK

Production

Spontaneous emission 4 10-7 s-

1

Collision n(H2) 100 cm-3 10-7 s-1

Destruction 10-9 s-1

10-17 s-1

10-7 cm3 s-1 10-9 cm3 s-1

' '' '

' ' ' '

exp( )J KJK JK JK J KJKJ K J K

k g E E

k g kT

H3+ + H2 (H5

+)* H3+ + H2

Detailed balance

Cosmic ray ionization

Dissociative recombination Proton hop reaction

0 =

Steady State

Oka, Epp ApJ, 613, 349 (2004)

Discovery of high temperature (T ~ 250 K), low density (n ≤ 100 cm-3) clouds

)2,2(

)3,3(

N

N

)1,1(

)3,3(

N

N

Oka & Epp, ApJ 613,349 (2004)

Gas in the CMZ : pre-H3+

Lazio & Cordes, ApJ 505, 715 (1998)

0.8 107 K

0.1 106 K 10 cm-3

0.1 102 K 104 cm-3

160 pc × 30 pc

7 × 107 KSuzaku Dec. 6, 2006

Koyama et al. PASJ 59, S245 (2007)

Surprise 5: Warm and diffuse gas

CO J = 1

(2,2) unstable

(3,3) metastable

(1,1) ground

Spectroscopy

Oka, Geballe, Goto, Usuda, McCall, ApJ 632, 882 (2005)

Surprise 6: Extragalactic H3+

Geballe, Goto, Usuda, Oka, McCall ApJ 644, 907 (2006)

Z = 0.05821

Chandra 20 pc × 20 pc (0.5 – 8) keV Muno et al. ApJ 589, 225 (2003)

Warwick, Sakano Decourchelle (2006) Revnivtsev et al. (2006)