Hard X-ray properties of cataclysmic variables
A brief summary is presented of results for AM Her, EX Hya, SS Cyg, and U Gem obtained with the high-energy detectors of the HEAO A2 experiment from 2-60 keV and the Solid State Spectrometer Experiment with the Monitor Proportional Control on the Einstein Observatory. It is found that the magnetic variable AM Her and the dwarf novae are similar in having bremsstrahlung of similar luminosity with temperatures for the dwarf novae that can approach that for AM Her and in flickering on a time scale of 5-15 min. But in general these dwarf novae temperatures are about 2-10 times lower. Only in Am Her is there evidence in the spectrum and eclipses for a small spot very close to the white dwarf surface. Most of the hard X-rays in SS Cyg, EX Hya, and U Gem are not pulsed, and the hard X-ray fluxes observed have never been significantly absorbed or degraded.