UV Observations of dwarf novae in quiescence - effects of evaporation?

Abstract

IUE spectra of dwarf novae in quiescence provide information on the inner part of the accretion disk. In the framework of the evaporation model the mass flow of about 10^-11^M_sun_/yr is understood as accretion via a hot corona above the cool inert disk. The UV radiation originates from the transition region between disk and corona, and from the white dwarf. If it is possible to separate the radiation from white dwarf and disk, the remaining disk spectrum allows conclusions on where the dominant emitting disk area is located. We compare results from observations of different systems with the prediction of the evaporation model.