X-Ray Emission Line Spectroscopy of Cataclysmic Variables. II. Temperatures and Densities from Line Ratios in the Chandra HETG Band

Abstract

We summarize the results of a line-by-line fitting analysis of the available spectra obtained using the Chandra High-Energy Transmission Grating. We confirm the existence of broad ionization and electron temperature ranges and high number densities in cataclysmic variables (CVs) of all subtypes. Temperatures range from ~0.4 keV to ~5-10 keV or more with a broad range detected in any given CV. In other words, single-temperature models do not describe the line emission. Number densities also cover a broad range, from 10^(12) to >10^(16) cm^(–3). We demonstrate that much of the plasma is in a nonequilibrium state; the Fe emission, however, may arise from plasma in the ionization equilibrium.

Files

Additional details