NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Fast molecular shocks. I - Reformation of molecules behind a dissociative shockThe physical and chemical processes that operate in the cooling gas behind a fast, dissociative, single-fluid shock propagating in a dense interstellar cloud are discussed. The treatment extends previous theoretical work on fast molecular shocks by including the effects of the conversion of Ly-alpha photons into radiation of the two-photon continuum and into H2 Lyman band emission lines, the effects of CO photodissociation following line absorption, and the formation and destruction of molecules containing the elements nitrogen, silicon, and sulphur, and of the complex hydrocarbons. Abundance profiles for the molecular species of interest are presented. After molecular hydrogen begins to reform, by means of gas phase and grain surface processes, the neutral species OH, H2O, O2, CO, CN, HCN, N2, NO, SO, and SiO reach substantial abundances. The molecular ions HeH(+), OH(+), SO(+), CH(+), H2(+), and H3(+), are produced while the gas is still hot and partially ionized. Emissions from them provide a possible diagnostic probe of fast molecular shocks.
Document ID
19890052996
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Neufeld, David A.
(Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Dalgarno, A.
(Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Date Acquired
August 14, 2013
Publication Date
May 15, 1989
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 340
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
89A40367
Funding Number(s)
CONTRACT_GRANT: NSF AST-86-17675
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available