A search for Ejecta Nebulae around Wolf-Rayet Stars using the SHS H$\alpha$ survey
Abstract
Recent large scale Galactic Plane H surveys allow a re-examination of the environs of Wolf-Rayet (WR) stars for the presence of a circumstellar nebula. Using the morphologies of WR nebulae known to be composed of stellar ejecta as a guide, we constructed ejecta nebula criteria similar to those of Chu (1991) and searched for likely WR ejecta nebula in the SHS H survey. A new Wolf-Rayet ejecta nebula around WR 8 is found and its morphology discussed. The fraction of WR stars with ejecta type nebulae is roughly consistent between the MilkyWay (MW) and LMC at around 5-6%, with the MW sample dominated by nitrogen rich WR central stars (WN type) and the LMC stars having a higher proportion of carbon rich WR central stars (WC type). We compare our results with those of previous surveys, including those of Marston (1997) and Miller & Chu (1993), and find broad consistency. We investigate several trends in the sample: most of the clear examples of ejecta nebulae have WNh central stars; and very few ejecta nebulae have binary central stars. Finally, the possibly unique evolutionary status of the nebula around the binary star WR 71 is explored.
Keywords
Cite
@article{arxiv.1006.0625,
title = {A search for Ejecta Nebulae around Wolf-Rayet Stars using the SHS H$\alpha$ survey},
author = {D. J. Stock and M. J. Barlow},
journal= {arXiv preprint arXiv:1006.0625},
year = {2015}
}
Comments
13 pages, 18 figures; Accepted for publication in MNRAS