A search for spectral variations in ROSAT observations of AM Her, VV Pup, BL HYI and UZ For
Abstract
We continue our series of papers examining ROSAT observations of AM Her stars which seek to improve our understanding of the physical processes occurring in the accretion region in these systems. In this paper, we present the results of a search for spectral variability in AM Her, VV Pup, BL Hyi and UZ For using ROSAT data. We find a significant variation in the soft X-ray component of AM Her, VV Pup and BL Hyi, and also a significant variation in the ratio of the soft to hard X-ray flux in AM Her and BL Hyi. We attribute these results to dense blobs of material impacting into the photosphere of the white dwarf. Further, the strength of the magnetic field of the accreting pole influences the proportion of dense blobs in the accretion stream.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- January 1996
- DOI:
- 10.1093/mnras/278.1.285
- Bibcode:
- 1996MNRAS.278..285R
- Keywords:
-
- STARS: INDIVIDUAL: AM HER;
- STARS: INDIVIDUAL: VV PUP;
- STARS: INDIVIDUAL: BL HYI;
- STARS: INDIVIDUAL: UZ FOR;
- STARS: MAGNETIC FIELDS;
- X-RAYS: STARS