AAS 203rd Meeting, January 2004
Session 44 Cataclysmic Variables, Novae
Poster, Tuesday, January 6, 2004, 9:20am-6:30pm, Grand Hall

## [44.02] The Impact of a Variable Efficiency Parameter on Common Envelope Evolution in Population Synthesis Studies of Cataclysmic Variables

C. R. Quandt, M. Politano (Marquette U.)

The efficiency with which orbital energy is transferred into the envelope has a direct influence on the outcome of the common envelope (CE) phase in the formation of cataclysmic variables (CVs). This efficiency, characterized by the parameter \alphaCE, is still quite uncertain. To the best of our knowledge, previous population synthesis studies of CVs have assumed \alphaCE to be a constant, independent of such quantities as the total mass of the primary, the core mass of the primary, and the mass of the secondary, for the entire population of binaries. In this study we relax that assumption and explore the impact of a variable \alphaCE on the outcome of the CE phase. The results presented in this poster are a preliminary step in a large parameter study whose goal is two-fold: (1) to identify interesting regions of parameter space for detailed study by researchers performing hydrodynamic calculations of the CE phase, and (2) to better model the common envelope phase in population synthesis studies of CVs.

This work was funded in part by NSF grant AST-0328484 to Marquette University.

Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.