Open AccessAsymmetric Wolf–Rayet winds: implications for gamma‐ray burst afterglows
Author(s) -
Eldridge J. J.
Publication year - 2007
Publication title -
monthly notices of the royal astronomical society: letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.067
H-Index - 122
eISSN - 1745-3933
pISSN - 1745-3925
DOI - 10.1111/j.1745-3933.2007.00297.x
Subject(s) - physics , ejecta , astrophysics , afterglow , supernova , gamma ray burst , asymmetry , astronomy , shock (circulatory) , jet (fluid) , wolf–rayet star , stars , mechanics , medicine , quantum mechanics
Recent observations of Wolf–Rayet (WR) binaries WR151 and WR155 infer that their stellar winds are asymmetric. We show that such asymmetries can alter the stellar‐wind bubble structure, bringing the wind‐termination shock closer to the WR star. If the wind asymmetry is caused by rotation, the wind density and distance to the wind‐termination shock are both decreased along the rotation axis by a factor of a few for the observed equator‐to‐pole wind density ratio of WR151. If this asymmetry lasts until core‐collapse the time taken to reach the wind‐termination shock by supernova ejecta or a gamma‐ray burst jet is reduced. This leads to a distorted structure of the supernova ejecta and makes it more likely a constant density environment is inferred from gamma‐ray burst afterglow observations.