RAWLINGS, JMC;
DREW, JE;
BARLOW, MJ;
(1994)
Astrophysically important reactions involving excited hydrogen.
In: Nenner, I, (ed.)
AIP Conference Proceedings.
(pp. pp. 437-443).
AIP
Preview |
Text
rawlings94_Conf_excH2.pdf - Published Version Download (570kB) | Preview |
Abstract
The associative ionization reaction H(n=2) + H → H+2 + e− is found to be a greater contributor to the H2 formation rate than the direct radiative association reaction H(n=2) + H → H2 + hν in most regions of astrophysical interest. The endothermicity (≂1.1 eV) of the reaction and the high departures from LTE that are required for the H I (n=2) level to be sufficiently populated restrict its significance to regions of high excitation. The reaction H(n=2) + H+ → H+2 + hν may be significant in highly excited ionized regions, such as planetary nebulae and shocks. Chemical models of circumstellar regions have been reassessed in the light of this information. A critical examination reveals tht excitation effects are, in general, very important in many astrophysical situations. Only exceptionally, will reactions involving the higher excited states (n≳2) be as significant as those involving H(n=2).
| Type: | Proceedings paper |
|---|---|
| Title: | Astrophysically important reactions involving excited hydrogen |
| Event: | Molecules and Grains in Space - 50th International Meeting of Physical Chemistry |
| Location: | MONT SAINTE-ODILE, FRANCE |
| Dates: | September 1993 |
| ISBN: | 1-56396-355-8 |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1063/1.46568 |
| Publisher version: | https://doi.org/10.1063/1.46568 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Science & Technology, Physical Sciences, Technology, Astronomy & Astrophysics, Physics, Atomic, Molecular & Chemical, Spectroscopy, Physics |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10096176 |
Archive Staff Only
 |
View Item |
