Contents of: VI/111/./abstract/JCASSINE_WR_VELOC.abs

The following document lists the file abstract/JCASSINE_WR_VELOC.abs from catalogue VI/111.
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 This proposal is concerned with determining the velocity structure in
 the winds of Wolf-Rayet (WR) stars.  Our goal is to understand the
 effects of rotation on the winds of WR stars. There is evidence from
 polarization and other observations that some WR stars have
 rotationally distorted winds. We have developed models for winds
 around stars that are rapidly rotating. Bjorkman and Cassinelli
 (1993) developed the Wind Compressed Disk model which showed that
 rotation can cause wind material from higher latitude regions to flow
 towards the equatorial plane. Cassinelli, Ignace and Bjorkman(1994)
 developed the Wind Compressed Zone (WCZ) model for WR stars, in which
 it is shown that a WR star with a slowly accelerating wind
 will develop large equatorial density enhancements even if the
 rotation rate is only 15 % of critical speed. We found that the
 velocity law determines the degree to which stellar rotation produces
 a density enhancement near the equatorial plane, and to verify the
 model, we require better information regarding the velocity increase
 versus radius. This is best derived from IR observations because
 regions farther out in the wind, hence at larger velocities, are
 sampled with increasing IR wavelengths. Observations of the
 recombination lines of HeII formed in this region will provide direct
 information about the magnitude of the outflow speed at various
 locations in the wind acceleration region. The ISO Short Wavelength
 Spectrometer (SWS) provides high sensitivity and resolution of
 spectral lines over a sufficiently broad range of wavelengths
 to derive the much needed data for the WR wind velocity structure.

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