Determination of Stellar Parameters and Lyman Continuum Fluxes for WC stars in the Galaxy and the LMC
Session 45 -- Early Type Stars
Display presentation, Wednesday, 9:20-6:30, Heller Lounge Room

## [45.12] Determination of Stellar Parameters and Lyman Continuum Fluxes for WC stars in the Galaxy and the LMC

K.R. Brownsberger (JILA), W.D. Vacca (UC Berkeley)

Wolf-Rayet stars of the carbon sequence (WC stars) exhibit ultraviolet and optical spectra dominated by strong broad emission lines, primarily from C and He ions. Because these lines are formed under non-LTE conditions in spherically extended, dense stellar winds, realistic models of these stars have only recently become available. Consequently, the intrinsic stellar parameters for most WC stars are unknown.

By combining ultraviolet, optical, and near-infrared data, we have constructed spectra covering $1100$ \AA\ to $1 {\mu} \rm{m}$ for a large number of WC stars located in the Galaxy and the LMC. We have determined the equivalent widths of a set of C and He emission lines in these spectra by fitting Gaussians to the observed line profiles. The WC stellar atmosphere models recently computed by Koesterke et al. (1993) yield contours of equivalent width values for various C and He lines as a function of stellar temperature and radius. Using our measured equivalent widths and these theoretical contours, we have have determined best-fit values for a number of important stellar parameters ($R$, $T_{eff}$, $L$, $\dot{M}$, and C abundance) for 30 WC stars. In addition we have used the resulting parameters to estimate the Lyman continuum fluxes produced by these stars. We discuss the variation of the resulting stellar parameters as a function of spectral subtype.