Recently, Advanced Laser Interferometer Gravitational-wave Observatory (aLIGO) detected gravitational wave (GW) transients from mergers of binary black holes (BHs). The system may also produce a wide-angle, relativistic outflow if the claimed short GRB detected by GBM is in real association with GW 150914. It was suggested that mergers of double neutron stars (or neutron star-black hole binaries), another promising source of GW transients, also produce fast, wide-angle outflows. In this paper, we calculate the high-energy gamma-ray emission arising from the blast waves driven by these wide-angle outflows. We find that TeV emission arising from the inverse-Compton process in the relativistic outflow resulted from mergers of binary BHs similar to those in GW 150914 could be detectable by ground-based IACT telescopes such as Cherenkov Telescope Array (CTA) if the sources occur in { a dense medium with density n>0.3cm−3}. For neutron star-neutron star (NS-NS) and NS-BH mergers, TeV emission from the wide-angle, mildly-relativistic outflow could be detected as well if they occur in a dense medium {with n>10−100cm−3.} Thus TeV afterglow emission would be a useful probe of the environment of the GW transients, which could shed light on the evolution channels of the progenitors of GW transients.
@article{arxiv.1608.02079,
title = {Probing the environment of gravitational wave transient sources with TeV afterglow emission},
author = {Qin-Yu Zhu and Xiang-Yu Wang},
journal= {arXiv preprint arXiv:1608.02079},
year = {2016}
}