The Neutrino Signal From Pair Instability Supernovae

Warren P. Wright, Matthew S. Gilmer, Carla Fröhlich, James P. Kneller

Published 2017-06-22Version 1

A very massive star with a carbon-oxygen core in the range of $64\;{\rm M_{\odot}}<M_{\mathrm{CO}}<133\;{\rm M_{\odot}}$ is expected to undergo a very different kind of explosion known as a pair instability supernova. Pair instability supernovae are candidates for superluminous supernovae due to the prodigious amounts of radioactive elements they create. Observations of a nearby pair-instability supernova would allow us to test current models of stellar evolution at the extreme of stellar masses. Much will be sought within the electromagnetic radiation we detect but we should not forget that the neutrino flux from a pair-instability supernova also contains unique signatures of the event that unambiguously identify this type of explosion. We calculate the expected neutrino flux at Earth from a one-dimensional pair-instability supernova simulation taking into account the full time and energy dependence of the neutrino emission and the flavor evolution through the outer layers of the star. We use the SNOwGLoBES event rate software to calculate the signal in five different detectors chosen to represent present or near future designs. We find a pair-instability supernova can easily be detected in multiple different neutrino detectors at the `standard' supernova distance of $10\;{\rm kpc}$ producing several events in DUNE, JUNE and SuperKamiokande. The proposed HyperKamiokande detector would detect events from a pair-instability supernova as far as $\sim 60\;{\rm kpc}$ allowing it to reach the Magellanic Clouds and the several very high mass stars known to exist there.