Short Gamma Ray Bursts and their Afterglow Signatures in Dense Stellar Systems

Understand

The hypothesis that short GRBs arise from the coalescence of binary compact stars has recently gained support.

• With this comes the expectation that the afterglow should bear the characteristic signature of a tenuous intergalactic medium (IGM).
• However, fits to the observational data suggest that some detected afterglows arise in relatively dense gaseous environments rather than in the low density IGM.
• Here we show that considering the effect of red giant winds in the core of a star cluster may resolve this paradox if short GRB progenitors are contained in such an environment and close encounters rather than pure gravitational wave emission brings the compact objects together.