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Revelation of a vast amount of warm and diffuse gas and high ionization rate

Revelation of a vast amount of warm and diffuse gas and high ionization rate in the Central Molecular Zone of the Galactic center by the Infrared Spectrum of H 3 + Takeshi Oka Department of Astronomy and Astrophysics and Department of Chemistry

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Revelation of a vast amount of warm and diffuse gas and high ionization rate

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  1. Revelation of a vast amount of warm and diffuse gas and high ionization rate in the Central Molecular Zone of the Galactic center by the Infrared Spectrum of H3+ Takeshi Oka Department of Astronomy and Astrophysics and Department of Chemistry The Enrico Fermi Institute, University of Chicago Tom Geballe Gemini Observatory Miwa Goto Max-Planck Institut für Astronomie Ben McCall University of Illinois at U-C Informal talk at Onsala Observatory: March 24, 2011 March 19, 1981

  2. C60 1973 Watson Herbst and Klemperer Black and Dalgarno Harry Kroto H–C≡C–C≡C–C≡C–C≡C–C≡N H–C≡C–C≡C–C≡C–C≡N H–C≡C–C≡C–C≡N 1975 X-ogen 1970 H3+ Buhl, Snyder, Klemperer

  3. H3+, the new astrophysical probe H 1975HC5N, HC7N, HC9N 1951 1980 Laboratory Spectrum Oka, Phys. Rev. Lett. 45, 531 T.G. H2 1989 - 95 1970 1973 1996 Interstellar H3+, Discovery, Dense Clouds Geballe, Oka, Nature 384, 334 1999 High H3+ abundance in the Galactic center H3+ 2002 Metastable H3+, Discovery, Galactic center Goto, McCall, Geballe, Oka, et al. PASJ 54, 951 1996 + • Revelation of warm and diffuse gass near GC • Oka, Geballe, Goto, Usuda, McCall, ApJ 632, 882 2008 Ubiquity Central 30 pc of the Galactic center Goto, Geballe, Oka, et al. ApJ 688, 306 2010 Exploring wider regions of the Galactic center Geballe, Oka, ApJ, 709, L70

  4. Telescopes and spectrometers Telescope D Spectrom. λ/Δλ UKIRT 3.8 m CGS4 40,000 Mauna Kea 1982 Subaru8.2 m IRCS 20,000Mauna Kea 2000 Gemini South 8 m Phoenix 60,000Cerro Pachon 2003 VLT 8.2 m CRIRES 100,000 Cerro Paranal 2006 Gemini North 8 m GENIRS 18,000 Mauna Kea 2011 Gemini North Gemini South Subaru UKIRT VLT

  5. High abundance of H3+ in the CMZ R(1, 1)u R(1, 0) 3 × 1014 cm-2 10-5 10% T. R. Geballe, Phil. Trans. Roy. Soc. Lond. A358, 2503 (2000) CMZ 400 pc

  6. Super-massive clusters Quintuplet Cluster GCS 3-2 1° × 1° 140 pc × 140 pc

  7. (J, K) = (3,3) metastable H3+, the fingerprint of GC Goto, McCall, Geballe, Usuda, Kobayashi, Terada, Oka, 2002, PASJ 54, 951 Spontaneous breakdown of symmetry (1,1) ground ParaI = 1/2 J OrthoI = 3/2 (3,3)metastable T ~ 250 K 8 hrs Metastable (3,3) 16 hrs (2,2) unstable n ≤ 100 cm-3 (2,2) 361 K 20.4 days (1,0) 27.2 days CO J = 1 (1,1) K Pan and Oka, 1987, ApJ, 305, 518 Oka and Epp, 2004, ApJ, 613, 349 Oka, Geballe, Goto, Usuda, McCall, 2005, ApJ, 632, 882

  8. Ubiquity of H3+ Sgr A* to 30 pc East 30 pc

  9. Simple chemistry of H3+: N(H3+) → ·L  ProductionH2→H2+ + e H2++ H2 →H + H3+ dn(H3+)/dt = n(H2) = ken(H3+)n(e) DestructionH3+ + e → H + H + H 7.3 ×10-8 cm3/s 1.6 ×10-4 1 L = 2 keN(H3+) (nC/nH)SV RX / f(H2) (1.8-6.1) ×1015 cm-2 3 (L)min = (1.3 – 4.3) ×105 cm/s  L 10-16 s-1 (0.4 – 1.4) kpc 10-15 s-140 - 140 pc Goto, Usuda, Nagata, Geballe, Indriolo, McCall, Suto, Henning, Morong, and Oka, ApJ, 668, 306 (2008)

  10. Super-massive clusters 1° × 1° 140 pc × 140 pc

  11. 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 band̲s Skrutskie et al. 2006, AJ, 131, 1163 - 1.2º < ℓ - ℓº < 1.2º - 0.1º < b - bº < 0.1º ~ 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 smoothness Low res. CO first overtone, 2.2 – 2.4μm Candidate stars location High res. H3+ and CO spectroscopy Selected stars

  12. The CO test Most old (late-type) cool stars are useless Bright dust-embedded stars with smooth spectrum are scarce

  13. New bright dust-embedded stars suitable for H3+ spectroscopy

  14. Two sightlines with remarkable H3+ spectrum Quintuplet,α, ι 0 – 30 pc East α ι Geballe and Oka, ApJ, 709, L70-73 (2010)

  15. Remarkable similarity between velocity profiles of 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. Zaal21 3 kpc Scutum Sgittarius H2O+ 110← 101 H3+ R(1,1)l H2O+ 111← 000 A&A June 22 2010 E. Falgarone et al. 2010 Geballe & Oka, 2010, ApJ, 709, L70 17 pc

  16. New category of gas in the CMZ Previous concept drastically changed T ~ 250 K n ~ 100 cm-3 L ~ 60 pc f ~30% ~ 1.5 × 1015 s-1 Schultheis et al. ApJ 495, 157 (2009) f: 80% 107-8 K ? 10% 104-6 K ne10 cm-3 Lazio & Cordes, ApJ, 505, 715 (1998) 10% 50 K 104 cm-3 2%

  17. X-ray: Chandra comes to rescue Chandra 20 pc × 20 pc (0.5 – 8) keV Muno et al. ApJ 589, 225 (2003) Warwick, Sakano Decourchelle (2006) Revnivtsev et al. (2006)

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