Prospects for future observations of off-axis short gamma-ray burst jets associated with binary neutron star mergers

In this thesis work, I assess the short- and long-term prospects for the joint detection of BNSs and SGRBs with next-generation γ-ray and GW detectors. I combine the Structured Jet (SJ) model developed by Salafia et al. (2015b; 2019) for SGRB prompt emission with the analytical model by Finn and Chernoff (1993) for the GW signal from the BNS inspiral phase and estimate future GW-SGRB joint detection rates, using the SJ profile inferred for GRB 170817A (Ghirlanda et al., 2019) and assuming that all BNS mergers can in principle produce a SGRB. I show that, despite the strong assumptions and simplifications of the adopted model, it provides realistic and consistent estimates of the detection rates of SGRBs and GWs obtained with current facilities, the Fermi/GBM and Swift/Burst Alert Telescope γ-ray detectors and the aLIGO O3a GW interferometer. I also show that, if the SJ profile of GRB 170817A is a relatively common feature of SGRBs, then there is no realistic probability of another coincident detection in the era of aLIGO at design sensitivity (i.e., when it has reached the best achievable sensitivity, the project sensitivity) and SVOM-type detectors. In the CE era, the expected rate of coincident SGRB prompt emission and GW signal detections is ≈ 21-22 yr−1 and ≈ 53-55 yr−1 for SVOM-like and THESEUS-like detectors, respectively. I discuss future prospects for this model, showing how future SGRB-GW joint detection can help to solve the tension on the Hubble parameter estimation and to provide tighter constraints on the NS EoS.