Tomography of polars

We are reviewing the power of Doppler tomography for detailed investigations of polars (magnetic cataclysmic binaries without accretion disk). Using high-resolution spectroscopy in combination with tomography as analytic tool, the structure and extent of the accretion flows and accretion curtains in the binaries can be uncovered and the irradiated and non-irradiated parts of the mass-donating secondary stars can be made visible. In addition we show, how basic system parameters like the binary inclination and the mass ratio can be addressed by tomography. (orig.)Proceedings of the Annapolis workshop on magnetic cataclysmic variables (MCV2), 22 refs.Available from TIB Hannover: RR 7310(98-26) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Modelling of the magnetic accretion flow in HU aquarii

We present a magnetic stripping model for AM Her type objects. Our model is based on an equilibrium condition between ram pressure and magnetic pressure in a stiff dipolar magnetic field. We investigate the detailed geometry of the stripping process, most of which can be tackled analytically. By involving additional numerical calculations, the model allows the prediction of phase-resolved spectra and Doppler tomograms. The emission line features from the companion star, the horizontal stream and the accretion curtain are identified with the emission line components found by Gaussian fitting to observational data of HU Aqr in its high accretion state. Given the simplicity of the model, its agreement with the observation is remarkably good and enables us to derive a number of physical quantities such as stellar masses and radii, total mass accretion rate, bulk temperature, and coupling density. (orig.)Available from TIB Hannover: RR 7310(98-31) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman