ROSAT and GINGA observations of the magnetic cataclysmic variable QQ Vul: evidence for two-pole accretion
Abstract
We report observations made in 1991 April of QQ Vul using the ROSAT and Ginga satellites. We find a spectral variation in soft X-rays that can be accounted for by an increase in the blackbody temperature by 3-5 eV, or by an increase in the intrinsic absorbing column density of (1.8-3.6)x10^19 cm^-2, between phases 0.5 and 1.0. Together with evidence for separated hard and soft X-ray emission regions, this suggests the presence of two-pole accretion. The emission region furthest from the secondary has a soft X-ray excess >~2.5, suggesting buried shocks arising from the accretion of dense filaments. The other emission region, closer to the secondary, is the site of the hard X-ray component. The hard X-ray data show a 6.7-keV iron K line of large equivalent width.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- April 1995
- DOI:
- 10.1093/mnras/273.3.742
- Bibcode:
- 1995MNRAS.273..742B
- Keywords:
-
- BINARIES: CLOSE;
- STARS: INDIVIDUAL: QQ VUL;
- STARS: MAGNETIC FIELDS;
- NOVAE;
- CATACLYSMIC VARIABLES;
- STARS: ROTATION;
- X-RAYS: STARS