Poster abstract details
Mapping emission line features in CVs
Abstract
Binary evolution predicts that the majority of the cataclysmic variables (CVs) should have evolved to short orbital periods. However, our sample with reliable systems parameters remains small as the faintness of the donor star prohibits traditional radial velocity studies using the photospheric absorption lines from it.
To address this problem, we have initiated a time-resolved spectroscopic survey of short period CVs covering both the traditionally used Balmer lines and so far neglected CaII triplet lines in the i-band. The Balmer emission lines are normally strong, but only map to a rather featureless disc in a Doppler Tomogram. We will show the contrast with maps created from the CaII lines. Not only do these maps show a better defined disc, but they also have the potential to reveal an emission sport from the donors star, which enables us to determine the binary mass ratio.
To address this problem, we have initiated a time-resolved spectroscopic survey of short period CVs covering both the traditionally used Balmer lines and so far neglected CaII triplet lines in the i-band. The Balmer emission lines are normally strong, but only map to a rather featureless disc in a Doppler Tomogram. We will show the contrast with maps created from the CaII lines. Not only do these maps show a better defined disc, but they also have the potential to reveal an emission sport from the donors star, which enables us to determine the binary mass ratio.