Help!!! Theory for Dissociative Recombination
of H3+ Still Needed
Takeshi Oka
Department of Astronomy and Astrophysics, and Department of Chemistry,
the Enrico Fermi Institute, University of Chicago
July 10, 2013 DR 2013 Paris
DR 2001 in Chicago, August 26-30
Ein Gespenst geht um in Europa.1848
Great development of TheoryLarsson et al., PRL 1997
100 − 1000
Jensen et al. PR 2001
Nature 30 August 2001
10
2
McCall et al. PR 2004
Jahn-Teller Interactions in the Dissociative Recombination of H3
+
Jungen & Pratt PRL 16 January 2009
Very high ζ in the Galactic center
Abundant in the Galactic center
Progress of H3+ Observations
1980 Oka, PRLLaboratory Spectrum
1996 Geballe & Oka, NatureDetection in Dense Clouds
Metastable H3+ in the Galactic center
Central 30 pc of the Galactic center140 pc West to 85 pc East of Sgr A
2013 Comprehensive, Morphology (Expanding Molecular Ring) Oka et al. ApJ
1998 Detection in Diffuse Clouds McCall, Geballe, Hinkle, Oka, Science
1999 Geballe, McCall, Hinkle, Oka, ApJ
2002 Diffuse Clouds Survey I McCall, Hinkle, Geballe, et al. ApJGoto, McCall, Geballe, et al. PASJ
2004 High ζ in Diffuse Clouds McCall, et al. NatureModel Calculation Oka & Epp ApJ
2005 Oka, Geballe, Goto, Usuda, McCall, ApJ
2007 Diffuse Clouds Survey II Indriolo, Geballe, Oka, McCall ApJ
2008 Goto, Geballe, Nagata, et al., ApJ2010 Geballe & Oka, ApJ2012 Diffuse Clouds Survey II Indriolo & McCall ApJ
1973 Interstellar Ion Chemistry Herbst & Klemperer ApJ Watson ApJ
The Central Molecular Zone
10-5
10%
300 pc
23 stars
A*
B1B2D C
E
αβγδθ
ι
λ
κ
140 pc West140 pc East
Very high ζ in the Galactic center
Abundant in the Galactic center
Progress of H3+ Observations
1980 Oka, PRLLaboratory Spectrum
1996 Geballe & Oka, NatureDetection in Dense Clouds
Metastable H3+ in the Galactic center
Central 30 pc of the Galactic center140 pc West to 85 pc East of Sgr A
2013 Comprehensive, Morphology (Expanding Molecular Ring) Oka et al. ApJ
1998 Detection in Diffuse Clouds McCall, Geballe, Hinkle, Oka, Science
1999 Geballe, McCall, Hinkle, Oka, ApJ
2002 Diffuse Clouds Survey I McCall, Hinkle, Geballe, et al. ApJGoto, McCall, Geballe, et al. PASJ
2004 High ζ in Diffuse Clouds McCall, et al. NatureModel Calculation Oka & Epp ApJ
2005 Oka, Geballe, Goto, Usuda, McCall, ApJ
2007 Diffuse Clouds Survey II Indriolo, Geballe, Oka, McCall ApJ
2008 Goto, Geballe, Nagata, et al., ApJ2010 Geballe & Oka, ApJ2012 Diffuse Clouds Survey II Indriolo & McCall ApJ
1973 Interstellar Ion Chemistry Herbst & Klemperer ApJ Watson ApJ
47 stars
The Central Molecular Zone
10-5
10%
300 pc
23 stars
A*
B1B2D C
E
αβγδθ
ι
λ
κ
140 pc West140 pc East
GCS 3-2
Very high ζ in the Galactic center
Abundant in the Galactic center
Progress of H3+ Observations
1980 Oka, PRLLaboratory Spectrum
1996 Geballe & Oka, NatureDetection in Dense Clouds
Metastable H3+ in the Galactic center
Central 30 pc of the Galactic center140 pc West to 85 pc East of Sgr A
2013 Comprehensive, Morphology (Expanding Molecular Ring) Oka et al. ApJ
1998 Detection in Diffuse Clouds McCall, Geballe, Hinkle, Oka, Science
1999 Geballe, McCall, Hinkle, Oka, ApJ
2002 Diffuse Clouds Survey I McCall, Hinkle, Geballe, et al. ApJGoto, McCall, Geballe, et al. PASJ
2004 High ζ in Diffuse Clouds McCall, et al. NatureModel Calculation Oka & Epp ApJ
2005 Oka, Geballe, Goto, Usuda, McCall, ApJ
2007 Diffuse Clouds Survey II Indriolo, Geballe, Oka, McCall ApJ
2008 Goto, Geballe, Nagata, et al., ApJ2010 Geballe & Oka, ApJ2012 Diffuse Clouds Survey II Indriolo & McCall ApJ
1973 Interstellar Ion Chemistry Herbst & Klemperer ApJ Watson ApJζ (s-1)
10-17
10-15
10-16
Dissociative Recombination of H3+:
ke Governs the Astrophysics of Diffuse Gas
Dense cloud n > 103 cm-3 L ~ pc CO
Diffuse cloud n ≤ 3 × 102 cm-3 L ~ 10 pc C+ + e-
Destruction H3+ + e → H + H + H, H2 + H
Production H2 → H2+ + e H2
+ + H2 → H + H3+
L = ke N(H3+) (nC/n(H2))
dn(H3+)/dt = n(H2)
= ken(H3+)n(e)
n(e) = n(C) N(H3+) = Ln(H3
+)
Petrignani et al. PR 2011
Worry 1
Worry 2
Kreckel et al. PR 2010Dos Santos et al. JCP 2007
Worry 3
Petrignani et al. PR 2011Dos Santos et al. JCP 2007
A plea
An important reaction
H2+ + H → H2 + H+
k = (6.4 ± 1.2) × 10–10 cm3 s-1
kL = 2.34 × 10–9 cm3 s-1
k = 1.49 × 10–9 cm3 s-1
Karpas, Anicich, Huntress, J. Chem. Phys. 1979, 70, 2872
Gonzáles-Lezana, Roncero, Honvault, Launay, Bulut, Aoiz, Bañares, J. Chem. Phys. 2006, 125, 094314
H2+ + H2 → H + H3
+
