Properties of Gamma-Ray Burst Progenitor Stars
Astrophysics
2009-11-13 v1
Abstract
We determine some basic properties of stars that produce spectacular gamma-ray bursts at the end of their life. We assume that accretion of the outer portion of the stellar core by a central black hole fuels the prompt emission, and that fall-back and accretion of the stellar envelope later produces the plateau in the X-ray light curve seen in some bursts. Using X-ray data for three bursts we estimate the radius of the stellar core to be ~ 1-3 x 10^10 cm, and that of the stellar envelope to be ~ 1-2 x 10^11 cm. The density profile in the envelope is fairly shallow, with \rho ~ r^-2. The rotation speeds of the core and envelope are ~ 0.05 and ~ 0.2 of the local Keplerian speed, respectively.
Cite
@article{arxiv.0807.0445,
title = {Properties of Gamma-Ray Burst Progenitor Stars},
author = {Pawan Kumar and Ramesh Narayan and Jarrett L. Johnson},
journal= {arXiv preprint arXiv:0807.0445},
year = {2009}
}
Comments
Science in press