Observing cosmological binary mergers with next generation neutrino and gravitational wave detectors

Abstract

We discuss the potential of detecting thermal neutrinos from matter-rich binary mergers, via a decades-long multi-messenger campaign involving a Mt-scale water Cherenkov neutrino detector and one or more next generation gravitational wave detectors, capable of observing mergers up to redshift $z\sim 2$. The search of neutrinos in time-coincidence with gravitational wave detections will allow to identify single neutrinos from individual mergers above the background, and to study their distributions in energy, redshift and type (double neutron-star or neutron-star-black hole merger) of the candidate sources. We find that, for merger rates consistent with current LIGO-Virgo constraints, and for a $100\mathrm{Mt}\cdot \mathrm{yr}$ exposure, between $\mathcal{O}(10^{-1})$ and $\mathcal{O}(10)$ neutrino events are expected. For extreme cases of mergers with more than $10^{52}$ ergs emitted in ${\bar{\nu }}_e$, the number of events can be as large as $\sim 100$, with sensitivity to mergers up to redshift $z\sim 0.5$ or so. Such scenarios can already be tested with a $10\mathrm{Mt}\cdot \mathrm{yr}$ exposure, resulting in constraints on the post-merger evolution of the systems being considered.

Comments: LaTeX, 13 pages, 8 figures, added Figure and references, accepted by Phys. Rev. D