Revealing nearby failed supernovae with megaton neutrino telescopes

We study the detectability of neutrino bursts from nearby direct black hole-forming collapses at Mt class detectors. Due to their high energetics, these bursts could be identified -- by the time coincidence of $N\geq 2$ or $N\geq 3$ events within a $\sim 1$ s time window -- from as far as $\sim 4-5$ Mpc away. This distance comprises several major, supernova-rich galaxies, so that failed supernova bursts could be detected at a rate of up to one per decade, comparable to the expected rate of the more common, but less luminous, neutron star-forming collapses. Thus, the detection of a failed supernova within the lifetime of a Mt detector is a realistic possibility. It might give the first evidence of direct black hole formation, with important implications on the physics this phenomenon.