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Central Molecular Zone (CMZ): the Treasure House of H 3 +. H 3 + : the novel probe of the CMZ. Takeshi Oka. The Enrico Fermi Institute, the University of Chicago. Thomas R. Geballe Gemini Observatory Miwa Goto Max Planck Institute for Astronomy Tomonori Usuda Subaru Telescope
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Central Molecular Zone (CMZ): the Treasure House of H3+ H3+: the novel probe of the CMZ Takeshi Oka The Enrico Fermi Institute, the University of Chicago Thomas R. GeballeGemini Observatory Miwa GotoMax Planck Institute for Astronomy Tomonori UsudaSubaru Telescope Benjamin J. McCallUniversity of Illinois, Urbana-Champaign Tetsuya Nagata Kyoto University Tomoharu Oka University of Tokyo Farhad Yusef-Zadeh Northwestern University Harvey Liszt National Radio Astronomy Observatory EFI mini-symposium April 20, 2007
R(1, 1)u R(1, 0) Geballe Phil. Trans. RSL A358, 2503 (2000) Central Molecular Zone the treasure house ofH3+ H3+ OH, H2CO, CO, CS, NH3, HCN CMZ Morris, Serabyn, ARA&A (1996) Mezger, Duschl, Zylka, A&A Rev. (1996)
Inferred face-on view of the CMZ The Expanding Molecular Ring 200 pc 130 pc EMR 145 km s-1 100 km s-1 Scoville, ApJ 175, L127 (1972) Oka, Hasegawa, Sato, Tsuboi, Miyazaki, ApJS 118, 455 (1998) Sawada, Hasegawa, Handa, Cohen, MNRAS 349, 1167 (2004)
Gas in the CMZ : pre-H3+ 160 pc × 30 pc 7 × 107 K Suzaku Dec. 6, 2006 Koyama et al. PASJ 59, S245 (2007) 0.8 107 K 0.1 106 K 10 cm-3 0.1 102 K 104 cm-3 Lazio & Cordes, ApJ 505, 715 (1998)
The Galactic center 27° × 40°
The Quituplet Stars Arches Quintuplet GCS 3-2 Central 1° × 1° 140 pc × 140 pc Binary pinwheel nebula, Science (2006)
Telescope and spectrometer UKIRT 3.8 m CGS4 8 km s-1 Mauna Kea 1982 Subaru8.2 m IRCS 15 km s-1 Mauna Kea 2000 Gemini South 8 m Phoenix 5 km s-1 Cerro Pachon 2003 VLT 8 m CRIRES ≤3 km s-1 Cerro Paranal 2006
The ideal rotational levels of H3+ Breaking Symmetry OrthoI = 3/2 J ParaI = 1/2 ++ = uuu Metastable 8 hrs (3,3) 16 hrs μ (2,2) 361 K 20.4 days Unstable 27.2 days Critical Density 200 cm-3 Ground (1,1) K Collision H3+ + H2→ (H5+)* → H3+ + H2 Interstellar NH3Oka, Shimizu, Shimizu, Watson, ApJ 165, L15 (1971) Interstellar H3+ Pan, Oka, ApJ 305, 518 (1986)
Spectroscopy (1,1) ground (3,3) metastable (2,2) unstable 130 pc 100 km s-1 CO J = 1 Oka, Geballe, Goto, Usuda, McCall, ApJ 632, 882 (2005)
Discovery of high temperature (T ~ 250 K), low density (n ≤ 100 cm-3) clouds Oka & Epp, ApJ 613,349 (2004)
Dimension of the discovered gas 7.3 ×10-8 cm3/s 1.6 ×10-4 1 ζL = 2 keN(H3+) (nC/nH)SV RX / f 3.1 ×1015 cm-2 3 - 10 COBE DIRBE Sodroski et al ApJ 452, 262 (1995) ζL = (2.5 – 8.4) ×105 cm/s ζ (s-1) L (pc) 120 pc 10-16 (0.8 - 2.1) k 10-1580 - 210 100 km s-1
ζ= 10-17s-1 ζ= 10-17s-1 Harvey Liszt Phil. Trans. R. Soc. A 364, 3049 (2006)
Eight YSO’s within 30 pc of the GC Subaru Telescope (2,2) densitometer (1,1) ground level (3,3) thermometer (2,2) densitometer (1,1) ground level (3,3) thermometer
The warm and diffuse gas is ubiquitous and has a large volume filling factor T = 220 K – 400 K n≤ 100 cm-3Lmin ~ 80 – 120 pc RX = 3 - 10
Gas in the CMZ : post-H3+ ? 0.8 107 K ? 0.1 106 K 10 cm-3 250 K102 cm-3 Warm and diffuse gas 0.1 102 K 104 cm-3 0.01 Lazio & Cordes, ApJ 505, 715 (1998)
Chandra 20 pc × 20 pc (0.5 – 8) keV Muno et al. ApJ 589, 225 (2003) Warwick, Sakano Decourchelle (2006) Revnivtsev et al. (2006)
Gas in the CMZ : post-H3+ ? 0.8 107 K ? 0.1 106 K 10 cm-3 250 K102 cm-3 Warm and diffuse gas 0.1 102 K 104 cm-3 0.01 Hyperstrong Radio-wave Scattering in the Galactic Center. II A Likelihood Analysis of Free Electrons in the Galactic Center Lazio & Cordes, ApJ 505, 715 (1998) Folded Fields as the Source of Extreme Radio-wave Scattering in the Galactic Center Goldreich and Sridhar, ApJ 640, L159 (2006)
Extragalactic H3+ in ULIRG Z = 0.05821 Geballe, Goto, Usuda, Oka, McCall ApJ 644, 907 (2006)
Controversies No hot gas in the Expanding Molecular Ring T. Oka F. Le Petit Diffuse gas cannot be that hot J. Black Infrared pumping (2, 0) Linnott & Rawlings Dynamically evolving cloud A&A 448, 425 (2006) F. Yusef-Zadeh 4 categories of gases ApJ 637, L101 (2006) (3, 3) (3, 0) (1, 0)
The Infrared Pumping V2 = 1 (2, 0) 25.3 ms Pump rate (s-1) Infrared photon flux (cm-2 s-1 Hz-1) 10.2 ms (3, 0) 3.75 hrs (3, 3) (1, 0) V = 0 A new estimate of the Galactic interstellar radiation field between 0.1 μm and 1000 μm T. A. Porter & A. W. Strong, Cosmic Ray Conference Pune (2005)
+ Three Proton System ++ = uuu p = uud n = udd I = 3/2 ortho I = 1/2 para
H – K’ AV = [(H-K’) + 0.097]/0.051 Cotera, Simpson, Erickson, Colgan, Burton, Allen, ApJS 129, 123 (2000)
Cotera, Simpson, Erickson, Colgan, Burton, Allen, ApJS 129, 123 (2000)
The Quintuplet Okuda et al. ApJ 351, 89 (1990)