Seismology of Accreting White Dwarfs

Arras, Phil; Townsley, Dean; Bildsten, Lars

Seismology of Accreting White Dwarfs

Authors

Arras, Phil

Townsley, Dean

Bildsten, Lars

Description

Pulsation modes have recently been observed in a handful of white dwarf (WD) primaries of cataclysmic variables, allowing an interesting new probe into the structure of accreting WD's. We briefly discuss the seismology of these objects, how stellar properties may be inferred from the observed mode frequencies, and mode driving mechanisms. For one pulsator, GW Lib, we have shown that a WD mass $M=1.05 M_\odot$ and accreted envelope mass $M_{\rm env}=0.4\times 10^{-4} M_\odot$ give the best match to the observed pulsation periods. A first exploration of mode driving favors $T_{\rm eff} = 14 000 K$ and a massive WD, but more work is necessary.
6 pages, 2 figures.To appear in The astrophysics of cataclysmic variables and related objects, ASP Conf. Ser.,eds. J.M. Hameury and J.P. Lasota