H3+ in the Central Molecular Zone of

the Galactic Center:Revelation of a New Category of Gas

Takeshi Oka

Department of Astronomy and Astrophysicsand Department of Chemistry,

The Enrico Fermi Institute, University of Chicago

Smiles, Kos, Greece, October 5, 2010

Tom Geballe Gemini Observatory

The Central Molecular Zone (CMZ)

The Treasure House of H3+

CMZ

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

T. R. Geballe, Phil. Trans. Roy. Soc. Lond. A358, 2503 (2000)

3 × 1014 cm-2

10-5

10%

400 pc

Discovery of the (J, K) = (3, 3) Metastable H3+

Metastable

27.2 days

20.4 days

Ortho I = 3/2

Para I = 1/2J

K

16 hrs8 hrs (3,3)

(2,2)

(1,1)

Pan and Oka, 1987, ApJ, 305, 518

(1,0)

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

361 K

CO J = 1

(2,2) unstable

(3,3) metastable

(1,1) ground

T ~ 250 K

n ≤ 100 cm-3

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

Spontaneous breakdown of symmetry

The 2 band of H3+

Oka, Phys. Rev. Lett. 45, 531 (1980)

2 = 2521 cm1

2q

= 0.158 D

J

K

(3,3)

(2,2)

(1,1)

Breaking Symmetry

μ

(1,0)

R(3,3)l

R(2,2)l R(1,1)l

R(1,0)

Telescopes and spectrometersTelescope D Spectrom. λ/Δλ UKIRT 3.8 m CGS4 40,000 Mauna Kea 1982 Subaru 　 8.2 m IRCS 20,000 Mauna Kea 2000Gemini South 8 m Phoenix 60,000 Cerro Pachon 2003VLT 8.2 m CRIRES 100,000 Cerro Paranal 2006 Gemini North 8 m GENIRS 18,000 Mauna Kea 2011

Subaru UKIRTGemini South

VLT

Gemini North

CMZ

Quintuplet Cluster

1° × 1° 140 pc × 140 pc

Super-massive clusters

GCS 3-2

H3+ near the GC

Surprises

UKIRT Huge column density; rich profile Geballe et al. ApJ 1999Subaru (3,3) metastable and (2,2) unstable H3

+ Goto et al. PASJ 2002 Thermalization model analysis Oka & Epp ApJ 2004Gem. S Revelation of warm and diffuse gas Oka et al. ApJ 2005 Review Oka PNAS 2006Subaru From the center to 30 pc east Goto et al. ApJ 2008VLT Scrutiny of the Central core Goto et al. 2010Gem. S Synthesis Oka et al. 2011

30 pc

Simple chemistry of H3+

Destruction H3+ + e → H + H + H

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

101

102

103

104

105

106

n(X

)

10-1

100

101

102

103

104

105

106

n(H)

Dense Clouds Diffuse Clouds

H2

HCO

C+H3

+

Production H2 → H2+ + e H2

+ +H2 →H + H3+

ζ

ζL = 2 ke N(H3+) (nC/nH)SV RX / f

7.3 ×10-8 cm3/s 1.6 ×10-4 1

(1.8-6.1) ×1015 cm-2 3

(ζL)min = (1.3 – 4.3) ×105 cm/s

ζ L

10-16 (0.4 – 1.4) kpc 10-15 40 - 140 pcGoto, Usuda, Nagata, Geballe, Indriolo, McCall, Suto, Henning, Morong, and Oka, ApJ, 668, 306 (2008)

dn(H3+)/dt = ζn(H2)

= ken(H3+)n(e)

McCall et al. Phys. Rev. A (2004)

Lazio & Cordes, ApJ, 505, 715 (1998)

0.8 107-8 K

0.1 104-6 K 10 cm-3

0.1 50 K 104 cm-3

Previous concept of gas in the CMZneed to be drastically changed

Warm and diffuse gas> 0.2 250 K 102 cm-3

f:

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

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

X-ray: Chandra comes to rescue

CMZ

Opening a New Vista

Search for bright and hot stars in the CMZGLIMPSE Point Source Catalogue of the Spitzer Space Telescope, L to M Ramírez et al. 2008, ApJS, 175, 147

2MASS photometry at J, H, and K bandsSkrutskie et al. 2006, AJ, 131, 1163

~ 2,000,000 stars

L < 7.5

~ 3,000 stars

(J – K)/(K – L) < 2.5K - L > 1.5J - K > 5

~ 300 stars

Low res. CO first overtone, 2.2 – 2.4μm

Candidate stars

Selected stars

High res. H3+ and CO spectroscopy

83 stars so far

10 new stars and 5 known stars

Star L J – K K – L (J – K)/(K – L)GCS3-2 3.03 7.33 3.16 2.32GCS4 3.71 7.65 3.45 2.22NHS21 4.62 7.03 2.76 2.55*NHS25 6.24 4.81* 1.27* 3.79*

brightness

youth

hotness

location

8

New bright and hot dust embedded stars suitable for H3

+ spectroscopy

Geballe and Oka, ApJ, 709, L70-73 (2010)

Two sightlines with remarkable H3+ spectrum

α

ι

Geballe and Oka, ApJ, 709, L70-73 (2010)

0 – 30 pc EastQuintuplet, α, ι

Geballe and Oka, ApJ 709, L70-73 (2010)

Iota, the Monster

“iota”, 85 pc East, Sgr B

High T

Low n

(3,3)

(2,2)

Subaru May 4, 2010

Remarkable similarity between velocity profilesof H3

+ toward Iota and H2O+, CH+ toward Sgr B2 Herschel observations of ortho- and para-oxidaniumyl (H2O+) in spiral arm clouds toward Sgr B2(M) ⋆

P. Schilke,1,2 C. Comito,2 H. S. P. M¨uller,1 E. A. Bergin,3 E. Herbst,14 D. C. Lis,4 D. A. Neufeld,20 T. G. Phillips,4 T. A. Bell,4 G.A. Blake5 E. Caux,6,7 C. Ceccarelli,8 J. Cernicharo,9 N. R. Crockett,3 F. Daniel,9,10 M.-L. Dubernet,11,12 M. Emprechtinger,4 P. Encrenaz,10 M. Gerin,10 T. F. Giesen,1 J. R. Goicoechea,9 P. F. Goldsmith,13 H. Gupta,13 C. Joblin,6,7 D. Johnstone,15 W. D. Langer13 W. B. Latter16 S. D. Lord,16 S. Maret,8 P. G. Martin,17 G. J. Melnick,18 K. M. Menten,2 P. Morris,16 J. A. Murphy,19 V. Ossenkopf,12,21 J. C. Pearson,13 M. P´erault,10 R. Plume,22 S.-L. Qin,13 S. Schlemmer,1 J. Stutzki,1 N. Trappe,19 F. F. S. van der Tak,21 C. Vastel,6,7 S. Wang,3 H. W. Yorke,13 S. Yu,13 N.Erickson,25 F.W. Maiwald,13 J. Kooi,4 A. Karpov,4 J. Zmuidzinas,4 A. Boogert,4 R. Schieder,1 and P. Zaal21A&A June 22 2010

Geballe & Oka, 2010, ApJ, 709, L70

H3+ R(1,1)l

H2O+ 111← 000

H2O+ 110← 101

17 pc

3 kpc ScutumSgittarius

E. Falgarone et al. 2010

αβ

HCl

Cl−

HCl+ H2Cl+

H2

H−

H2+ H3

+

H2O

OH−

H2O+ H3O+

1 - 10

~ 3.3

Dariusz Lis

Floris van der Tak

107

?????

http://www.dn.se/nyheter/vetenskap/the-frontrunners-of-the-nobel-prize-2010-1.1181788

Chemistry: Maybe the spectra of spectroscopy – a close up as well as all the way to outer space? William Moerner has developed a spectrometer that can discern individual molecules of elements. William Klemperer has developed methods to establish what molecules are present in the dust clouds between the stars. Maybe a combination of those two, and maybe Richard Zare and/or Allen Bard will be in on it.