An Interstellar Conduction Front Within a Wolf-Rayet Ring Nebula Observed with the GHRS
Abstract
With the High Resolution Spectrograph aboard the Hubble Space Telescope we obtained high signal-to-noise (S/N > 200 - 600 per 17 km/s resolution element) spectra of narrow absorption lines toward the Wolf-Rayet star HD 50896. The ring nebula S308 that surrounds this star is thought to be caused by a pressure-driven bubble bounded by circumstellar gas (most likely from a red supergiant or luminous blue variable progenitor) pushed aside by a strong stellar wind. Our observation has shown for the first time that blueshifted (approximately 70 km/s relative to the star) absorption components of C IV and N V arise in a conduction front between the hot interior of the bubble and the cold shell of swept-up material. These lines set limits on models of the conduction front. Nitrogen in the shell appears to be overabundant by a factor ~10. The P Cygni profiles of N V and C IV are variable, possibly due to a suspected binary companion to HD 50896.
Cite
@article{arxiv.astro-ph/9610186,
title = {An Interstellar Conduction Front Within a Wolf-Rayet Ring Nebula Observed with the GHRS},
author = {Bram Boroson and Richard McCray and Christina Oelfke Clark and Jonathan Slavin and Mordecai-Mark Mac Low and You-Hua Chu and Dave Van Buren},
journal= {arXiv preprint arXiv:astro-ph/9610186},
year = {2009}
}
Comments
32 pages, Latex, to appear in the Astrophysical Journal, April, 1997