  We study the gravitational-wave peak luminosity and radiated energy of
quasicircular neutron star mergers using a large sample of numerical relativity
simulations with different binary parameters and input physics. The peak
luminosity for all the binaries can be described in terms of the mass ratio and
of the leading-order post-Newtonian tidal parameter solely. The mergers
resulting in a prompt collapse to black hole have largest peak luminosities.
However, the largest amount of energy per unit mass is radiated by mergers that
produce a hypermassive neutron star or a massive neutron star remnant. We
quantify the gravitational-wave luminosity of binary neutron star merger
events, and set upper limits on the radiated energy and the remnant angular
momentum from these events. We find that there is an empirical universal
relation connecting the total gravitational radiation and the angular momentum
of the remnant. Our results constrain the final spin of the remnant black-hole
and also indicate that stable neutron star remnant forms with super-Keplerian
angular momentum.
