We compute the local rate of events similar to GRB 170817A, which has been recently found to be associated with a kilonova (KN) outburst. Our analysis finds an observed rate of such events of RKN∼352−281+810 Gpc−3yr−1. After comparing at their face values this density of sGRB outbursts with the much higher density of Binary Neutron Star (BNS) mergers of 1540−1220+3200 Gpc−3yr−1, estimated by LIGO-Virgo collaboration, one can conclude, admittedly with large uncertainty that either only a minor fraction of BNS mergers produces sGRB/KN events or the sGRBs associated with BNS mergers are beamed and observable under viewing angles as large as θ≤40∘. Finally we provide preliminary estimates of the number of sGRB/KN events detected by future surveys carried out with present/future ground-based/space facilities, such as LSST, VST, ZTF, SKA and THESEUS.
@article{arxiv.1809.04295,
title = {GW170817: implications for the local kilonova rate and for surveys from ground-based facilities},
author = {M. Della Valle and D. Guetta and E. Cappellaro and L. Amati and M. T. Botticella and M. Branchesi and E. Brocato and L. Izzo and M. A. Perez-Torres and G. Stratta},
journal= {arXiv preprint arXiv:1809.04295},
year = {2018}
}