The X-ray spectrum of the polar BY Cam

Abstract

ASCA and GINGA X-ray data from the magnetic Cataclysmic Variable BY Cam show that the spectrum is strongly affected by complex absorption, probably from the pre-shock accretion column. The intrinsic emission from the shock is significantly better described by the theoretically expected multi-temperature structure rather than a single temperature plasma, but with cyclotron cooling probably suppressing the highest temperature bremsstrahlung components. Reflection of this multi-temperature emission from the white dwarf surface is also significantly detected. All these spectral complexities are required to gain a physically self-consistent picture of the X-ray spectrum.