Neutrino signals from neutron star implosions to black holes

We calculate the neutrino luminosity when dark matter is captured by a neutron star that eventually implodes to form a low-mass black hole. A central disk forms out of the ejected material with a finite radial extension, density, temperature, and lepton fraction, producing fainter neutrino luminosities and colder associated spectra than expected in regular core-collapse supernova and black hole--neutron star mergers. The emitted gravitational wave signal from the implosion should be detectable with ultrahigh-frequency resonant cavities in the range ~0.1--1 GHz.