Title: The abundance of H3(+) ions in dense interstellar clouds
Abstract: view Abstract Citations (37) References (23) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Abundance of H 3 + Ions in Dense Interstellar Clouds Lepp, S. ; Dalgarno, A. ; Sternberg, A. Abstract Several simple relationships are written down which express the abundances of C+, He+, H3+, OH, and H2O in dense interstellar clouds as functions of the cosmic-ray ionization rate. It is argued that the primary source of OH is photodissociation of H2O by cosmic-ray induced photons. The abundance of H3+ is derived from observations of OH and predicted to be typically about 2 x 10-5 cm-3, independent of density. Lower limits of respectively 4 x 10-18 s-1 and 8 x 10-18 s-1 are obtained for the cosmic-ray ionization rates in the clouds L134 and B335. The abundances of H3+ are likely to be enhanced in regions in which the DCO+/HCO+ ratio is large. Publication: The Astrophysical Journal Pub Date: October 1987 DOI: 10.1086/165636 Bibcode: 1987ApJ...321..383L Keywords: Abundance; Cosmic Rays; Gas Density; Hydrogen Ions; Ion Production Rates; Molecular Clouds; Computational Astrophysics; Hydroxyl Emission; Interstellar Chemistry; Interstellar Matter; Photodissociation; Astrophysics; COSMIC RAYS: GENERAL; INTERSTELLAR: ABUNDANCES; INTERSTELLAR: MOLECULES full text sources ADS | data products SIMBAD (2)