Heating and ionization by X-ray photoelectrons.
Abstract
The paper employs a Monte Carlo method to calculate the heating, secondary ionization and Lyman-alpha excitation produced by the energetic electrons released by X-ray photoionization of interstellar gas. The new features of this computation are the inclusion of current cross sections for electron collisional ionization and excitation of H, He(0) and He(+), and a more accurate treatment of the energy spectrum of secondary electrons produced in collisional ionization of these species. These calculations are of value for studies of the interaction of hard X-rays with interstellar gas of various ionization fractions.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1979
- DOI:
- 10.1086/157553
- Bibcode:
- 1979ApJ...234..761S
- Keywords:
-
- Astrophysics;
- Atomic Excitations;
- Gas Heating;
- Interstellar Gas;
- Photoelectrons;
- Photoionization;
- X Rays;
- Electron Energy;
- Energy Distribution;
- Energy Spectra;
- Helium;
- High Energy Electrons;
- Hydrogen;
- Lyman Alpha Radiation;
- Monte Carlo Method;
- Astrophysics;
- Interstellar Gas:Heating;
- Interstellar Gas:Ionization;
- Interstellar Gas:X Rays