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Title: HOT HYDROGEN IN DIFFUSE CLOUDS

Abstract

Laboratory evidence suggests that recombination of adsorbed radicals may cause an abrupt temperature excursion of a dust grain to about 1000 K. One consequence of this is the rapid desorption of adsorbed H{sub 2} molecules with excitation temperatures of this magnitude. We compute the consequences of injection of hot H{sub 2} into cold diffuse interstellar gas at a rate of 1% of the canonical H{sub 2} formation rate. We find that the level populations of H{sub 2} in J = 3, 4, and 5 are close to observed values, and that the abundances of CH{sup +} and OH formed in reactions with hot hydrogen are close to the values obtained from observations of diffuse clouds.

Authors:
 [1];  [2];  [3]
  1. INAF-Osservatorio Astronomico di Cagliari, Strada n.54, Loc. Poggio dei Pini, I-09012 Capoterra (Italy)
  2. Department of Physics and Astronomy, University of Waterloo, Ontario N2L 3G1 (Canada)
  3. Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)
Publication Date:
OSTI Identifier:
22039064
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 755; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; ASTRONOMY; ASTROPHYSICS; COSMIC DUST; DESORPTION; EXCITATION; HYDROGEN; INFRARED SPECTRA; MOLECULES; RADICALS; RECOMBINATION

Citation Formats

Cecchi-Pestellini, Cesare, Duley, Walt W., and Williams, David A., E-mail: ccp@oa-cagliari.inaf.it, E-mail: wwduley@uwaterloo.ca, E-mail: daw@star.ucl.ac.uk. HOT HYDROGEN IN DIFFUSE CLOUDS. United States: N. p., 2012. Web. doi:10.1088/0004-637X/755/2/119.
Cecchi-Pestellini, Cesare, Duley, Walt W., & Williams, David A., E-mail: ccp@oa-cagliari.inaf.it, E-mail: wwduley@uwaterloo.ca, E-mail: daw@star.ucl.ac.uk. HOT HYDROGEN IN DIFFUSE CLOUDS. United States. doi:10.1088/0004-637X/755/2/119.
Cecchi-Pestellini, Cesare, Duley, Walt W., and Williams, David A., E-mail: ccp@oa-cagliari.inaf.it, E-mail: wwduley@uwaterloo.ca, E-mail: daw@star.ucl.ac.uk. Mon . "HOT HYDROGEN IN DIFFUSE CLOUDS". United States. doi:10.1088/0004-637X/755/2/119.
@article{osti_22039064,
title = {HOT HYDROGEN IN DIFFUSE CLOUDS},
author = {Cecchi-Pestellini, Cesare and Duley, Walt W. and Williams, David A., E-mail: ccp@oa-cagliari.inaf.it, E-mail: wwduley@uwaterloo.ca, E-mail: daw@star.ucl.ac.uk},
abstractNote = {Laboratory evidence suggests that recombination of adsorbed radicals may cause an abrupt temperature excursion of a dust grain to about 1000 K. One consequence of this is the rapid desorption of adsorbed H{sub 2} molecules with excitation temperatures of this magnitude. We compute the consequences of injection of hot H{sub 2} into cold diffuse interstellar gas at a rate of 1% of the canonical H{sub 2} formation rate. We find that the level populations of H{sub 2} in J = 3, 4, and 5 are close to observed values, and that the abundances of CH{sup +} and OH formed in reactions with hot hydrogen are close to the values obtained from observations of diffuse clouds.},
doi = {10.1088/0004-637X/755/2/119},
journal = {Astrophysical Journal},
number = 2,
volume = 755,
place = {United States},
year = {Mon Aug 20 00:00:00 EDT 2012},
month = {Mon Aug 20 00:00:00 EDT 2012}
}