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

Understand

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 $100~{\rm Mt\cdot yr}$ 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 $\mathrel{{\bar \nu}_e}$, the number of events can be as large as $\sim 100$, with sensitivity to mergers up to redshift $z\sim 0.5$ or so.