Molecular hydrogen emission from photodissociation regions

2007 ◽  
pp. 24-31
Author(s):  
Tetsuo Hasegawa
Keyword(s):  
Molecular Hydrogen ◽  
Hydrogen Emission ◽  
Photodissociation Regions

scholarly journals Near-IR Fluorescent Molecular Hydrogen Emission from NGC 2023

1998 ◽  
Vol 15 (2) ◽  
pp. 194-201 ◽  
Author(s):  
Michael G. Burton ◽  
J. E. Howe ◽  
T. R. Geballe ◽  
P. W. J. L. Brand
Keyword(s):  
Energy Range ◽  
Spectral Resolution ◽  
Ground State ◽  
Molecular Hydrogen ◽  
Line Emission ◽  
Hydrogen Line ◽  
Atmospheric Transmission ◽  
Hydrogen Emission ◽  
Near Ir ◽  
Photodissociation Regions

AbstractSpectra from 1 to 2·5 μm, at 230–430 spectral resolution, are presented of the fluorescent molecular hydrogen line emission from two locations in the reflection nebula NGC 2023. Over 100 H2 lines can be identified in the spectra, although blending and poor atmospheric transmission mean that reliable level column densities can only be obtained from 35 lines. This latter group includes lines from v = 1–8 and v = 10, spanning an energy range from 6000 to 45,000 K above the ground state. These data may be used to constrain models of photodissociation regions and of fluorescent excitation for molecular hydrogen.

The Kinematics and Excitation of Molecular Hydrogen Emission in the Planetary Nebula BD +30o3639

1998 ◽  
Vol 498 (1) ◽  
pp. 267-277 ◽  
Author(s):  
D. L. Shupe ◽  
J. E. Larkin ◽  
R. A. Knop ◽  
L. Armus ◽  
K. Matthews ◽  
...  
Keyword(s):  
Planetary Nebula ◽  
Molecular Hydrogen ◽  
Hydrogen Emission

scholarly journals ULTRALUMINOUS STAR-FORMING GALAXIES AND EXTREMELY LUMINOUS WARM MOLECULAR HYDROGEN EMISSION ATz= 2.16 IN THE PKS 1138–26 RADIO GALAXY PROTOCLUSTER

2012 ◽  
Vol 751 (1) ◽  
pp. 13 ◽  
Author(s):  
P. Ogle ◽  
J. E. Davies ◽  
P. N. Appleton ◽  
B. Bertincourt ◽  
N. Seymour ◽  
...  
Keyword(s):  
Molecular Hydrogen ◽  
Radio Galaxy ◽  
Star Forming ◽  
Hydrogen Emission

The Onset of Molecular Hydrogen Emission from Proto–planetary Nebulae

1998 ◽  
Vol 509 (2) ◽  
pp. 728-732 ◽  
Author(s):  
David A. Weintraub ◽  
Tracy Huard ◽  
Joel H. Kastner ◽  
Ian Gatley
Keyword(s):  
Molecular Hydrogen ◽  
Planetary Nebulae ◽  
Hydrogen Emission

The unusual morphology of molecular hydrogen emission in the planetary nebula J900

1995 ◽  
Vol 109 ◽  
pp. 1173 ◽  
Author(s):  
D. L. Shupe ◽  
L. Armus ◽  
K. Matthews ◽  
B. T. Soifer
Keyword(s):  
Planetary Nebula ◽  
Molecular Hydrogen ◽  
Hydrogen Emission

Infrared images of ionized and molecular hydrogen emission in S106

1990 ◽  
Vol 354 ◽  
pp. 242 ◽  
Author(s):  
Saeko S. Hayashi ◽  
Tetsuo Hasegawa ◽  
Masuo Tanaka ◽  
Masahiko Hayashi ◽  
Colin Aspin ◽  
...  
Keyword(s):  
Molecular Hydrogen ◽  
Infrared Images ◽  
Hydrogen Emission

scholarly journals Excitation of H2 and HD in Shocks and PDRs

2000 ◽  
Vol 197 ◽  
pp. 191-201 ◽  
Author(s):  
F. Bertoldi ◽  
B. T. Draine ◽  
D. Rosenthal ◽  
R. Timmermann ◽  
S. K. Ramsay Howat ◽  
...  
Keyword(s):  
Emission Line ◽  
High Velocity ◽  
Molecular Hydrogen ◽  
Line Emission ◽  
High Excitation ◽  
Vibrationally Excited ◽  
Photodissociation Regions ◽  
Very High

Photodissociation regions (PDRs) and shocks give rise to conspicuous emission from rotationally and vibrationally excited molecular hydrogen. This line emission has now been studied with ISO and from the ground in great detail. A remarkable discovery has been that toward the Orion outflow and other shock-excited regions, the H2 level populations show a very high excitation component. We suggest that these high-excitation populations may arise from non-thermal pumping processes, such as H2 formation and high-velocity ion-molecule collision in partially dissociative shocks. In PDRs such as NGC 7023 however, formation pumping is always less important than fluorescent pumping.We furthermore present two HD emission line detections toward Orion Peak 1. This enables the first comparison of the H2 and the HD excitation, which surprisingly turn out to be identical.

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