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H 3 +

H 3 +. Search for hot and bright stars for H 3 + spectroscopy Near the Galactic center. Takeshi Oka. Department of Astronomy and Astrophysics and Department of Chemistry The Enrico Fermi Institute, University of Chicago. and T. R. Geballe. Gemini Observatory.

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H 3 +

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  1. H3+

  2. Search for hot and bright stars for H3+spectroscopy Near the Galactic center Takeshi Oka Department of Astronomy and Astrophysics and Department of Chemistry The Enrico Fermi Institute, University of Chicago and T. R. Geballe Gemini Observatory OSU international symposium on molecular spectroscopy, June 25, 2009

  3. 8 stars within 30 pc from GC all show the warm and diffuse gas (2,2) (1,1) (3,3) (2,2) (1,1) (3,3) T = 220 - 400 K n≤ 100 cm-3 Goto, Usuda, Nagata, Geballe, McCall, Indriolo, Suto, Henning, Morong, Oka, ApJ, 688, 306 (2008)

  4. A lucky summer at the Gemini South Observatory

  5. The great ocean of truth lay all undiscovered before us Long pathlength of H3+ We must find hot and bright young stars !

  6. Old (late-type) stars are useless

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

  8. 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 Star LJ – KK – L (J – K)/(K – L) GCS3-2 3.03 7.33 3.16 2.32 GCS4 3.71 7.65 3.45 2.22 NHS21 4.62 7.03 2.76 2.55* NHS25 6.24 4.81*1.27*3.79* ~ 2,000,000 stars brightness L < 7.5 ~ 3,000 stars youth J - K > 5 K - L > 1.5 (J –K)/(K – L)< 2.5 ~ 300 stars 83 stars so far hotness Low res. CO first overtone, 2.2 – 2.4μm Candidate stars 10 new stars and 5 known stars location High res. H3+ and CO spectroscopy Selected stars

  9. Typical hot young star and cool old star (both very bright!) Hot Cool CO 2 – 0 3 – 1 4 – 2 5 – 3 Spectra taken by UIST spectrometer of the UKIRT

  10. Medium resolution spectroscopy at UKIRT using UIST spectrometer

  11. Candidate stars # Star Spectrum location 1 J 17432173 728_24 K=6.5 L=3.8 132 pc West 2 J 17432988 808_56 K=8.8 L=4.5 127 pc West 3 J 17441867 728_28 K=10.0 L=6.4 80 pc West ? 4 J 17444083 731_64 K=9.4 L=6.4 45 pc West 5 J 17450483 815_33 K=9.0 L=6.5 30 pc West 6 J 17452861 815_71 K=9.2 L=6.6 10 pc out of plane 7 J 17461514 731_68 K=10.1 L=5.6 Close to Quint. 8 J 17461783 731_72 K=7.8 L=5.5 Close to Quint. 9 J 17463219 728_40 K=9.2 L=6.4 43 pc East 10 J 17470264 808_143 K=10.2 L=6.5 ?? 11 J 17470898 815_79 K=10.4 L=6.6 84 pc East. 12 J 17474486 731_76 K=10.3 L=4.7 96 pc East

  12. High resolution spectroscpy for radial location

  13. Tons of work ahead of us The central 2 pc Circum nuclear disk Adaptive Optics needed VLT, Subaru The central 30 pc Super-massive clusters Velocity analysis GS → IRTF Whole CMZ Hunting stars UKIRT Observation Subaru, GS → SOAR

  14. Understanding a monster X-ray γ-ray Radio continuum HII region Radio recomb. Fine structure H3+ IR abs. CO IR abs H2 FIR H2 IR emission Radio CO, CS, HCN, CH emission

  15. H3+

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