Soft X-Ray Spectra and Light Curves of Cataclysmic Variables
Abstract
We report on spectral and temporal analysis of the pointed ROSAT observations of a dozen cataclysmic variables. All the sufficiently strong sources show rapid aperiodic variations (``flickering") but no definite periods were found. Limits on the pulsed fraction of two DQ Her star candidates (TW Pic and TT Ari) were found to be ~ 30%. The stars at high binary inclination (IP Peg, V2051 Oph, V347 Pup, V Sge, and H0928+50) were found to be very feeble X-ray sources, presumably because of X-ray absorption in the accretion disk. A search for X-ray eclipses was basically negative, although this result is tainted by the very low count rates. Orbital modulations in the X-ray hardness ratio were found or suspected in three stars (RXJ1940.2-1025, WZ Sge, and GP Com), suggesting the possibility of X-ray absorption in an orbital structure (accretion column, accretion stream, or hot spot at the outer edge of the disk). Better orbital ephemerides and/or modelling of the physics and geometry of the X-ray absorption are needed to evaluate this possibility.
- Publication:
-
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 1994
- Bibcode:
- 1994AAS...185.2117H