On the iron Kα complex in magnetic cataclysmic variables

We present a compilation of spectra of the iron Kα region in magnetic cataclysmic variables, using data from the Chandra High-Energy Transmission Grating (HETG). The H-like, He-like and fluorescent components are clearly resolved, and there are hints of the structure within each component. The different shape of the He-like component in AM Her might be related to greater cyclotron cooling in this star. A surprising absence of Doppler shifts in the H- and He-like components implies that the X-ray emission is predominantly from the denser, lower velocity base of the accretion columns. This absence will allow Astro-E2 to resolve the structure in each component, leading to temperature diagnostics. We do not confirm the report that the H- and He-like components of AO Psc are Compton-broadened; however, we do detect a Compton-downshifted shoulder to the fluorescent line of GK Per. Further, a Doppler-shifted wing of this line arises in the high-velocity, pre-shock flow.