No CrossRef data available.
Article contents
EUVE Spectrophotometry of QS Tel: The Second Pole Becomes Active
Published online by Cambridge University Press: 12 April 2016
Abstract
We present results of EUVE spectrophotometry of the EUV luminous polar, QS Tel (RE1938-461), together with contemporaneous optical photometry and spectroscopy. In marked contrast to the ROSAT survey observations, the EUVE light curve shows two flux maxima per orbital cycle, implying that both magnetic poles were active. A deep, narrow dip is observed during one of the two flux maxima, exhibiting a complex morphology which includes pronounced flickering behaviour. Although this feature is probably caused by stream occultation of the emission region, the apparent lack of spectral hardening at this time disfavours photoelectric absorption by cold gas as the dominant source of opacity. Whilst the overall EUVE spectrum can be characterized by a low temperature (~15eV) blackbody, implying a large soft/hard component flux ratio (~50), tentative evidence of an absorption edge from NeVI at 85A and lines due to NeVIII and NeVII at 98Å and 116Å respectively indicate that more sophisticated models must be employed. Quasi-simultaneous optical photometry shows a substantial change in the light curve over an interval of just 3 days and little evidence of correlated behaviour with the EUV flux. We consider the implications of these results on the accretion geometry and the structure of the accretion flow.
- Type
- VI. Cataclysmic Variable Stars
- Information
- International Astronomical Union Colloquium , Volume 152: Astrophysics in the Extreme Ultraviolet , 1996 , pp. 331 - 335
- Copyright
- Copyright © Kluwer 1996