bally et al. 2010, apj, 721, 137

Bally et al. 2010, ApJ, 721, 137Molinari et al, 2011, ApJ, 735, L33

Double ring or single ring

Molinari et al, 2011, ApJ, 735, L33

Sawada et al. 2004

J. Kormendy & R. C. Kennicutt, 2004, ARA&A

Scoville, 1972

EMR

Rodríguez-Fernandez et al. 2006

N. Z. Scoville, 1972, ApJ, 175, L127T. Sawada et al. 2001, ApJS, 136, 189

T. Sawada et al. 2004, MNRAS, 349, 1167

Molecular face-on views of the GC

Rodríguez-Fernandez et al. 2006 Bally et al. 2010, ApJ, 721, 137

Molinari et al, 2011, ApJ, 735, L33

Ubiquity of H3+

Sgr A* to 30 pc East

30 pc

1.00

0.95

0.90

0.85

0.80

0.75

0.70

-200 -150 -100 -50 0 50 100

GCS 4

NHS 21

NHS 25

NHS 42

FMM 361

Goto, et al. 2008, ApJ, 688, 306

H3+ and CO

α 140 pc Westι 85 pc East

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

Two sightlines with remarkable H3+ spectrum

α 140 pc West

ι 68 pc East

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

0 – 30 pc EastQuintuplet, α, ι

1.00

0.95

0.90

0.85

0.80

0.75

0.70

-200 -150 -100 -50 0 50 100

GCS 4

NHS 21

NHS 25

NHS 42

FMM 361

H3+ as thermometer and densitometer

Metastable

27.2 days

Ortho I = 3/2

Para I = 1/2J

K

(3,3)

(2,2)

(1,1)

Pan and Oka, 1987, ApJ, 305, 518

(1,0)361 K

CO R(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

T n

Spontaneous breakdown of symmetry

1.00

0.95

0.90

0.85

0.80

0.75

0.70

-200 -150 -100 -50 0 50 100

GCS 4

NHS 21

NHS 25

NHS 42

FMM 361

Sofue 1995, PASJ, 47, 551

Future 2: 2 Herschel Proposal OA2

Molinari et al, 2011, ApJ, 735, L33