Intermediate polars in the Swift/BAT survey: Spectra and white dwarf
  masses
  White dwarf masses in cataclysmic variables are difficult to determine
accurately, but are fundamental for understanding binary system parameters, as
well as binary evolution. We investigate the X-ray spectral properties of a
sample of Intermediate Polars detected above 15 keV to derive the masses of
their accreting white dwarfs. We use data from the Swift/BAT instrument which
during the first 2.5 yrs of operation has detected 22 known intermediate
polars. The X-ray spectra of these sources are used to estimate the mass of the
white dwarfs. We are able to produce a mass estimate for 22 out of 29 of the
confirmed intermediate polars. Comparison with previous mass measurements shows
good agreement. For GK Per, we were able to detect spectral changes due to the
changes in the accretion rate. The Swift/BAT detector with its combination of
sensitivity and all-sky coverage provides an ideal tool to determine accurate
white dwarf masses in intermediate polars.
