X-ray line emission from supernova remnants. I - Models for adiabatic remnants

Supernova remnants (SNRs) are among the brightest extended X-ray sources and include some of the richest sources of line emission in the X-ray sky. The problem of nonequilibrium ionization presents one of the major complications in the analysis of SNR spectra. SNR ages are typically shorter than the time required to reach ionization equilibrium. A comprehensive theoretical study of SNR spectra involves an investigation over at least a two-dimensional parameter space, the temperature and degree of ionization being allowed to vary independently. The present investigation is the first published attempt at such a complete study of SNR spectra. The first part of this investigation is converned with the detailed results of extensive computations of nonequilibrium spectra of SNR blast waves in the Sedov phase. Attention is given to ionization and emission processes, and models as working tools for analyzing the X-ray spectra of adiabatic SNRs.