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Paper: The Structure of EUV Accretion Regions of AM HER Stars
Volume: 157, Annapolis Workshop on Magnetic Cataclysmic Variables
Page: 173
Authors: Sirk, Martin M.; Howell, Steve B.
Abstract: We have developed a model of the high-energy accretion region for magnetic cataclysmic variables and applied it to EUVE observations of 10 AM Her systems. The major features of the EUV light curves are well described by the model. The light curves exhibit a large variety of features such as eclipses of the accretion region by the secondary star and the accretion stream and broad dips caused by material very close to the accretion region. While all the observed features of the light curves are highly dependent on viewing geometry, none of the light curves are consistent with a flat, circular accretion spot whose light curve would vary solely from projection effects. The accretion region immediately above the white dwarf (WD) surface is a source of EUV radiation caused by either a vertical extent to the accretion spot or Compton scattering off of electrons in the accretion column or, very likely, both. Our model yields spot sizes averaging 0.06 Rwd, or f 1 times 10^{-3}, and average spot heights of 0.023 Rwd.
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