Hard X-ray Emission of Intermediate polars

Cataclysmic variables represent a significant fraction of all INTEGRAL detections in hard X-ray/soft γ-ray. Our deep survey of all known intermediate polars revealed 5 new sources, previously undetected by INTEGRAL. Our analysis based on observational data from INTEGRAL/IBIS and INTEGRAL/JEM-X showed that the fluxes of some intermediate polars are long-term variable. Moreover, this hard X-ray/soft γ-ray variability is correlated with the changes in optical spectral band. The broad-band spectra (3 - 100 keV) of surveyed intermediate polars can be well fitted by a thermal bremsstrahlung model with reflection from the surface of the white dwarf in some cases.