1. Absorption line survey toward the Galactic center II Miwa Goto Max-Planck-Institut fuer Astronomie Heidelberg, Germany contribution from Subaru to the exploitation of H3+ in space

2. Here is my acknowledgement to B. J. McCall (Univ. of Illinois) T. R. Geballe (Gemini Observatory) T. Oka (Univ. of Chicago) T. Usuda (Subaru Telescope) Japan Society of Promotion of Science

3. What is Subaru? It is a Telescope. Atop at Mauna Kea in Hawaii 8.2-m primary mirror the world largest class Joined the force of exploitation of H3+ in the ISM since 2000

4. Honolulu Hil o Honolulu Hilo Mauna Kea Hilo London Subaru Base facility in Hilo Subaru Telescope How to get there

5. What is so special about Subaru and its spectrograph Usually, these two are conflicting demands in observation. unlike with CO H3+ so nasty scattered all over the 3um region still needs high spectral resolution Velocity dispersion in interstellar cloud < 10 km/s 3.4 um 4.1 um Oka Phys. Rev. Lett. 45, 531 (1980) …it is particularly suited for absorption line survey Which requires wide wavelength coverage

6. Subaru/IRCS selling point: wide wavelength coverage Atmospheric transmission IRCS (Infrared Camera and Spectrograph H3+ lines

7. Subaru/IRCS selling point: wide wavelength coverage High dispersion Low dispersion

8. Survey type observation 2-fold: - extend the series of lines for one object - Detect lines in as many object 8-m primary helps Cross-dispersing spectrograph helps Is powerful mean of observation when a new field is just open Absorption line Survey

9. Brief history Pre Subaru: 1996; detection in ISM ( If there is H3+ in space? ) 1998-1999: diffuse cloud enigma widely recognized by community Subaru I: 2002; metastable state Subaru II: 2005; R(3, 3)l is ubiquitous in the Galactic center. Subaru III: (extension toward wavelength) (Extension of sources.) (Tom-sans talk yesterday) (McCall et al. ) (Oka et al. 2005) (Geballe & Oka 1996) 2006-; What comes next?

10. Subaru II It is ubiquitous! R(2,2)l : - R(2,2)l R(3,3)l R(1,0)l+R(1,1)u R(3,3)l : + R(1,0)l : + At least in Galactic Center But only in the Galactic Center

11. Dots Line Area -180 pc Subaru III: How far the boundary extend? Where R(3,3)l disappears?

12. Trick to increase Absorption line survey Use late type stars. ( we know it is not clean) But See, Can use it. R(1,1) R(1,0)

13. Thanks!! B. J. McCall (Univ. of Illinois) T. R. Geballe (Gemini Observatory) T. Oka (Univ. of Chicago) T. Usuda (Subaru Telescope) Japan Society of Promotion of Science