X-ray absorption and the POST - auger decay spectrum of multielectronatoms.
Abstract
Auger ionization frequently leaves an atom in an excited state which decays to the ground state by a spontaneous radiative cascade. This process has not previously been considered and is potentially important as a source of line emission following X-ray absorption. We show that the post-Auger decay yields a rich spectrum of UV and optical emission lines as a direct signature of the X-ray absorption.
Our results are applied to some astrophysical problems of interest. We show that the direct X-ray-induced emission considered here may contribute to the UV line spectra of quasars and Seyfert galaxies, as well as those of Galactic compact X-ray sources. We also find that the neutral gas responsible for the absorption turnover in the soft X-ray spectrum of the Crab Nebula may be a detectable source of neutral oxygen fluorescent Kα emission at 0.525 keV if the gas is local to the nebula. The same gas should be undetectable in its O III post-Auger decay lines.- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1981
- DOI:
- 10.1086/158813
- Bibcode:
- 1981ApJ...245..335S