ROSAT observations of UZ For : evidence of a structured X-ray emission region.
Abstract
We present the results of ROSAT X-ray and EUV observations of the eclipsing AM Her star UZ For. Data have been obtained during faint and bright phases and, most interestingly, during the rise interval when the emission region appears over the limb of the white dwarf. The source is seen weakly in the X-ray telescope during the faint phase. We find that the rise to the bright phase is resolved, which is direct evidence of a spatially extended soft X-ray emission region and which places constraints on the size of the emission region. We show evidence that the blackbody temperature in the rise interval is about 10 percent lower than in the bright phase. The soft X-ray excess is at least a factor of 7.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 1993
- DOI:
- 10.1093/mnras/262.4.993
- Bibcode:
- 1993MNRAS.262..993R
- Keywords:
-
- Eclipsing Binary Stars;
- Rosat Mission;
- Stellar Magnetic Fields;
- Stellar Radiation;
- X Ray Stars;
- Extreme Ultraviolet Radiation;
- Infrared Astronomy;
- Variable Stars;
- Astrophysics