Binary star progenitors of long gamma-ray bursts

Abstract

We present a binary channel for the progenitors of long gamma-ray bursts. We test the idea of producing rapidly rotating Wolf-Rayet stars in massive close binaries through mass accretion and consecutive quasi-chemically homogeneous evolution. The binary channel presented here may provide a means for massive stars to obtain the required high rotation rates. Moreover, it suggests that a possibly large fraction of long gamma-ray bursts occurs in runaway stars. This can have important observational consequences for both the positions of GRBs, and their afterglow properties.