Multiple ionization by low-energy cosmic rays and the abundance of highly ionized interstellar atoms

Abstract

view Abstract Citations (2) References (19) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Multiple ionization by low-energy cosmic rays and the abundance of high ionized interstellar atoms. Watson, W. D. Abstract Calculations are presented and employed in conjunction with available experimental data to estimate cross sections for multiple ionization of atoms by low-energy (MeV/nucleon) cosmic rays. The efficiency of multiple ionization increases rapidly with the charge of the cosmic ray, so that heavier (Z at least 6) nuclei are the dominant contributors for cosmic-ray compositions deduced from higher-energy cosmic rays. Multiple ionization dominates in the production of certain highly ionized atoms by cosmic rays under typical interstellar conditions. N v is considered explicitly, and its production rate by low-energy cosmic rays is estimated to be enhanced by a factor of about 5 to 100. For a low-energy cosmic-ray flux of the proposed intensity for heating and ionizing the interstellar gas, the predicted abundance for N v will be near or above the observed limit if previous calculations are otherwise correct. Publication: The Astrophysical Journal Pub Date: February 1976 DOI: 10.1086/154149 Bibcode: 1976ApJ...204...47W Keywords: Abundance; Atomic Excitations; Cosmic Rays; Gas Ionization; Interstellar Gas; Ion Production Rates; Ionization Cross Sections; Particle Interactions; Radiant Heating; Astrophysics full text sources ADS |