Search for supernova neutrino bursts at super-kamiokande

Abstract

We report the results of a search for neutrino bursts from supernova explosions using the Super-Kamiokande detector. Super-Kamiokande is sensitive to core-collapse supernova explosions via observation of their neutrino emissions. The expected number of events comprising such a burst is similar to 10(4), and the average energy of the neutrinos is in the range of a few tens of MeV for a core-collapse supernova explosion at a typical distance in our galaxy ( 10 kpc); this strong signal means that the detection efficiency anywhere within our galaxy and well past the Magellanic Clouds should be 100%. We examined a data set taken from 1996 May to 2001 July, and from 2002 December to 2005 October, corresponding to 2589.2 live days. However, there is no evidence of such a supernova explosion during the data-taking period. The 90% C. L. upper limit on the rate of core-collapse supernova explosions out to distances of 100 kpc is found to be 0.32 SN yr(-1).