X ray spectra of cataclysmic variables
Abstract
X ray spectral parameters of cataclysmic variables observed with the 'Einstein' imaging proportional counter were determined by fitting an optically thin, thermal bremsstrahlung spectrum to the raw data. Most of the sources show temperatures of order a few keV, while a few sources exhibit harder spectra with temperatures in excess of 10 keV. Estimated 0.1 to 3.5 keV luminosities are generally in the range from 1030 to 1032 erg/sec. The results are consistent with the x rays originating in a disk/white dwarf boundary layer of non-magnetic systems, or in a hot, post-shock region in the accretion column of DQ Her stars, with a negligible contribution from the corona of the companion. In a few objects column densities were found that are unusually high for interstellar material. It was suggested that the absorption occurs in the system itself.
- Publication:
-
Columbia Univ. Annual Report
- Pub Date:
- September 1990
- Bibcode:
- 1990cuny.rept.....P
- Keywords:
-
- Cataclysmic Variables;
- Proportional Counters;
- Spectrum Analysis;
- Stellar Spectra;
- X Ray Spectra;
- Bremsstrahlung;
- Brightness Temperature;
- Coronas;
- Imaging Techniques;
- Stellar Luminosity;
- Astrophysics