Doppler tomography of intermediate polar spin cycles

Abstract

I collect emission line profiles for seven intermediate polars, phase-resolved over the spin cycles. I then present the first systematic application of Doppler tomography to the spin cycles, with the aim of investigating whether spin-cycle tomography is a useful diagnostic tool. Four stars show line emission from material falling onto both magnetic poles of the white dwarf, but three others show line emission from only the upper pole. Tomography can map the extent and shape of the line-emitting accretion curtains, but it can also give misleading results if the line flux changes significantly over the spin cycle.