Multi-Messenger Astrophysics with THESEUS: Synergies with next generation gravitational wave detectors

¹ ITP, Goethe Universität, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main, Germany
² INAF, Istituto di Astrofisica e Planetologia Spaziali, via Fosso del Cavaliere 100, I-00133 Roma, Italy
³ INAF, Osservatorio di Astrofisica e Scienza dello Spazio, via Gobetti 93/3, I-40139 Bologna, Italy
⁴ INAF, Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova, Italy
⁵ INFN, Sezione di Padova, Via Francesco Marzolo 8, I-35131 Padova, Italy
⁶ Gran Sasso Science Institute (GSSI), 67100 L’Aquila, Italy
⁷ INFN, Laboratori Nazionali del Gran Sasso, 67100 Assergi, Italy
⁸ Department of Astronomy and Astrophysics, PSU, 525 Davey Lab, University Park, PA 16802, USA
⁹ Institute for Gravitation & the Cosmos, PSU, University Park, PA 16802, USA

^* e-mail: giulia.stratta@inaf.it

Published online: 6 March 2025

Abstract

Among several breakthrough discoveries in multi-messenger astrophysics achieved in the last decade, there is the first short gamma-ray burst (GRB) associated to the gravitational wave (GW) source GW170817, which confirmed binary neutron star (NS-NS) mergers as short GRB progenitors. More identifications are expected over the next years, but it will only be during the second half of the 2030s that statistically large samples of NS-NS mergers, as well as other GW sources as neutron star-black hole mergers and core collapse supernovae, will become available thanks to the anticipated one order of magnitude increase in sensitivity of next-generation GW detectors. Here we discuss how a gamma/X-ray surveyor like THESEUS will play a crucial role in independently detecting and accurately localizing the electromagnetic counterparts of such GW events, enabling multi-band follow-up campaigns and detailed source characterization of an unprecedented number of multi-messenger sources.