XMM-Newton observations of the asynchronous polar BY Cam
Abstract
We report observations of the asynchronous polar BY Cam made using XMM-Newton. We find evidence for two accretion regions which have significantly different spectra. In both regions we find evidence for hard X-ray emission from the post-shock flow while we observe a distinct soft X-ray blackbody component in only one. We detect two emission lines in the RGS detectors which we attribute to nitrogen NVI and NVII: the first time that nitrogen lines have been detected in an X-ray spectrum of a cataclysmic variable. In the time interval where we observe short time-scale variability we find the hard X-ray light curve is correlated with the softest energies in the sense that the hard X-rays trail the soft X-rays and are anti-correlated. We suggest that there are a small number of dense blobs of material which impact the white dwarf without forming a shock and release an amount of optically thick material which obscures hard X-rays for a short duration.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- August 2002
- DOI:
- 10.1046/j.1365-8711.2002.05536.x
- arXiv:
- arXiv:astro-ph/0203444
- Bibcode:
- 2002MNRAS.334..805R
- Keywords:
-
- binaries: eclipsing;
- stars: individual: BY Cam;
- stars: magnetic fields;
- novae;
- cataclysmic variables;
- X-rays: stars;
- Astrophysics
- E-Print:
- Accepted for publication in MNRAS, 7 pages