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High ionization rate and a vast amount of warm and diffuse gas in the Central Molecular Zone

High ionization rate and a vast amount of warm and diffuse gas in the Central Molecular Zone Takeshi Oka Department of Astronomy and Astrophysics and Department of Chemistry The Enrico Fermi Institute, University of Chicago. Tom Geballe Gemini Observatory

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High ionization rate and a vast amount of warm and diffuse gas in the Central Molecular Zone

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  1. High ionization rate and a vast amount of warm and diffuse gas in the CentralMolecular Zone 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 The emerging, multi-wavelength picture of the Galactic center environments Max-Planck Haus, Heidelberg October 18, 2011

  2. Infrared spectrum of H3+, the new probe for the GC T, n, ζ, L H 1951 Cosmic - ray H2 → H2+ + e ζ ~ 10-17 – 10-14 s-1 H2 p 1970 1973 H2+ + H2 → H + H3+ H3+ (1,0) 1996 + (3,3) (2,2) (1,1) Geballe and Oka, Nature, 384,334 (1996) T. Oka, Phys. Rev. Lett. 45, 531 (1980)

  3. H3+ as thermometer and densitometer T n Spontaneous breakdown of symmetry (1,1) ground ParaI = 1/2 J OrthoI = 3/2 (3,3)metastable T ~ 250 K Metastable (3,3) (2,2) unstable (2,2) n ≤ 100 cm-3 361 K (1,0) CO R(1) 27.2 days (1,1) K Pan and Oka, 1987, ApJ, 305, 518 Oka, Geballe, Goto, Usuda, McCall, 2005, ApJ, 632, 882

  4. < 1 ? 1.1×10-7 cm3/s 1.6 ×10-4 (1.8 ‒ 6.1) ×1015 cm-2 > 3 H3+ as dosimeter and yardstick L  ProductionH2→H2+ + e H2++ H2 →H + H3+ dn(H3+)/dt = n(H2) = ken(H3+)n(e) DestructionH3+ + e → H + H + H L = 2 keN(H3+) (nC/nH)SV RX / f(H2) L > (2.0 – 6.5) ×105 cm/s  L 10-16 s-1 > 0.6 – 2.1 kpc 10-15 s-1 > 60 – 210 pc

  5. H3+is ubiquitous ,  Geballe, Oka, 2010, ApJ, 709, L70 ε+ ε- η+ λ α+ θ+ δ+ θ- GCS 3-2 Oka, Geballe, Goto, Usuda, McCall, 2005, ApJ, 632, 882 Goto, Usuda, Nagata, Geballe, McCall, Indriolo, Suto, Henning, Morong, Oka, 2008, ApJ, 688, 306 30 pc

  6. H3+the most direct probe for soft cosmic ray  L  N(H3+) Dense clouds L = 2 kLN(H3+) (nC/nH)1.5 L = (0.6 – 2.3)  102 cm s-1 = 3  10-17s-1L = (0.6 – 2.3) pc N(H3+)obs = (1.1 – 5.2)  1014 cm-2 McCall, Geballe, Hinkle, Oka, 1999, ApJ, 522, 338 Diffuse clouds L = 2 keN(H3+) (nC/nH)/ f(H2) L = (0.4 – 4.4)  104 cm s-1 N(H3+)obs = (0.21 – 2.4)  1014 cm-2 = 4.5  10-16 s-1L = (3 – 29) pc Indriolo, Geballe, Oka, McCall, 2007, ApJ, 671,1736 Galactic center L = 2 keN(H3+) (nC/nH)SV RC/H / f(H2) L > (1.2 – 4.2)  105 cm s-1 = 2  10-15 s-1L > (24 – 84) pc N(H3+)obs = (1.8 – 6.1)  1015 cm-2 RC/H 3– 6.7 Goto, Usuda, Nagata, Geballe, McCall, Indriolo, Suto, Henning, Morong, Oka, 2008, ApJ, 688, 306 Rolleston et al. 2000, A&A, 363, 557 Esteban et al. 2005, ApJ, 618, L95 RX 3– 10, > 3 Sodroski, et al. 1995, ApJ 452, 262 Arima, Sofue, Tsujimoto, 1996, PASJ 48, 275

  7. Previous concept drastically changed Enter a new category of molecular gas T ~ 250 K n ≤ 100 cm-3 L > 60 pc f > 30% > 2 × 1015 s-1 f 80% 107-8 K GCDX GCPE 10% 104-6 K ne10 cm-3 10% 50 K 104 cm-3 Lazio & Cordes, ApJ, 505, 715 (1998)

  8. Much less dense gas in the CMZ 1 ι68 pc East α140 pc West H3+ CO

  9. Much less dense clouds in the CMZ 2 T. Oka et al. ApJ. 493, 730 (1998) Schultheis et al. ApJ 495, 157 (2009) Cotera et al. ApJ (2000)

  10. Previous concept drastically changed Enter a new category of molecular gas T ~ 250 K n ≤ 100 cm-3 L > 60 pc f > 30% > 2 × 1015 s-1 f 80% 107-8 K GCDX GCPE 10% 104-6 K ne10 cm-3 1% 10% 50 K 104 cm-3 Lazio & Cordes, ApJ, 505, 715 (1998)

  11. Much less GCDX and the ultra-hot plasma gas Chandra 20 pc × 20 pc (0.5 – 8) keV Muno et al. ApJ 589, 225 (2003)

  12. Future 1 Increasing stars ε+ ε- η+ λ α+ θ+ δ+ θ- 30 pc

  13. Future 2: Using surrogates, OH+, H2O+, CH+ 1 Remarkable similarity of velocity profiles H3+f(H2) = 1 ? H2O+ f(H2) = 0.1 H2O+ 110← 101 17 pc H3+ R(1,1)l H2O+ 111← 000 Schilke et al. 2011, A&A, 521, L11 E. Falgarone et al. 2011 Geballe & Oka, 2010, ApJ, 709, L70

  14. Future 2: 2 Herschel Proposal OA2 Molinari et al, 2011, ApJ, 735, L33

  15. Double ring or single ring EMR Sawada et al. 2004 Scoville, 1972 Rodríguez-Fernandez et al. 2006 J. Kormendy & R. C. Kennicutt, 2004, ARA&A Molinari et al, 2011, ApJ, 735, L33

  16. 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

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

  18. Ubiquity of H3+ Sgr A* to 30 pc East Goto, et al. 2008, ApJ, 688, 306 30 pc

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

  20. 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

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