Abstract
A recent model1 for the X-ray emission of non-magnetic cataclysmic variables suggests that most of the observed hard X-ray flux originates in a radiatively-cooling quasi-hydrostatic corona surrounding the white dwarf as it accretes from its companion. We present here some results from a ∼7.5-h EXOSAT observation of the dwarf nova SS Cygni in its quiescent state, which confirm many of the predictions of this model. In particular, they show that the X-ray luminosity, Lx, and bremsstrahlung temperature, T, obey the predicted relationship Lx α T3/2+2ε. The results further suggest that the emitting region covers an appreciable fraction f∼0.1–1 of the white dwarf's surface, and also that transport processes into the white dwarf cause most of the luminosity to emerge at soft X-ray/extreme ultraviolet wavelengths.
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King, A., Watson, M. & Heise, J. An X-ray corona in SS Cygni?. Nature 313, 290–291 (1985). https://doi.org/10.1038/313290a0
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DOI: https://doi.org/10.1038/313290a0
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