The X-ray spectra of VW Hydri during the outburst cycle
Abstract
We report six BeppoSAX X-ray observations of VW Hyi during and after the outburst of Sep 23 1998. The outburst flux is lower than the quiescent flux in the entire observed energy band (0.1-10 keV), in agreement with earlier observations. The X-ray spectra are fitted with two-temperature plasma and cooling flow spectral models. These fits show a clear spectral evolution in X-rays for the first time in VW Hyi: the hard X-ray turn-up after the outburst is reflected in the emission measure and the temperature. Moreover, during outburst the 1.5-10 keV flux decreases significantly. We argue that this is not consistent with the constant flux during a ROSAT outburst observation made eight years earlier. We conclude from this observation that there are significant differences between outburst X-ray lightcurves of VW Hyi.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- September 1999
- DOI:
- 10.48550/arXiv.astro-ph/9908096
- arXiv:
- arXiv:astro-ph/9908096
- Bibcode:
- 1999A&A...349..588H
- Keywords:
-
- ACCRETION;
- ACCRETION DISKS;
- STARS: INDIVIDUAL: VW HYI;
- STARS: NOVAE;
- CATACLYSMIC VARIABLES;
- Astrophysics
- E-Print:
- Accepted for publication in A&