Two Sightlines toward the Galactic Center with Remarkable H 3 + and CO Spectra Takeshi Oka Department of Astronomy and Astrophysics and Department of Chemistry, The Enrico Fermi Institute, University of Chicago June 24, Columbus Symposium Tom Geballe Gemini Observatory Geballe, T.R. & Oka, T. 2010, ApJ, 709, L70 Tomonori Usuda Miwa Goto Subaru Telescope Max-Planck Institute for Astronomy

H 3 + near the GC Surprises Huge column density; rich profile Geballe et al. ApJ 1999 (3,3) metastable and (2,2) unstable H 3 + Goto et al. PASJ 2002 Thermalization model analysis Oka & Epp ApJ 2004 Revelation of warm and diffuse gas GS Oka et al. ApJ 2005 Review Oka PNAS 2006 From the center to 30 pc east Subaru Goto et al. ApJ 2008 Scrutiny of the Central core VLT Goto et al Synthesis Gemini South Oka et al pc

Lazio & Cordes, ApJ, 505, 715 (1998) K K 10 cm K 10 4 cm -3 Previous concept of gas in the CMZ need to be drastically changed Warm and diffuse gas 250 K 10 2 cm -3 f: X-ray emitting Ultrahot plasma ζ·Lζ·L

Old (late-type) stars are useless

Nagata, Hyland, Straw, Sato, Kawara, ApJ, 406, 501 (1993) Bright and hot young stars are scarce

Search for bright and hot stars in the CMZ GLIMPSE 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 bands Skrutskie 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. H 3 + and CO spectroscopy 83 stars so far 10 new stars and 5 known stars Star L J – K K – L (J – K)/(K – L) GCS GCS NHS * NHS * 1.27* 3.79* brightness youth hotness location 8

New bright and hot dust embedded stars suitable for H 3 + spectroscopy Geballe and Oka, ApJ, 709, L70-73 (2010)

Two sightlines with remarkable H 3 + 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

H 3 + ν 2 ←0 (2,2) l ←(1,1) l Iota 84.5 pc East 1.8 pc below Gemini South H 2 O ← B 1 Sgr B pc East 1.4 pc above HIFI Ossenkoph et al. Astro-ph. 1005, 2521, 2010 Two Monsters

“alpha”, 140 pc West, 2.7 pc below Alpha, the elegant Geballe and Oka, ApJ 709, L70-73 (2010) H. Liszt, ApJL, 82, 495 (1992) 13 CO Sgr E, 144 pc West, 20 pc above

α β

“alpha”, 140 pc West, 2.7 pc below Geballe and Oka, ApJ 709, L70-73 (2010) Expanding Molecular Ring