Upper Limits on Gamma-ray Emission from Supernovae Serendipitously Observed with H.E.S.S.

Abstract

It is hypothesized that some young supernovae might have the correct properties to accelerate cosmic rays, which in turn might generate gamma-ray emission by-products. We search for gamma-ray excesses towards supernovae in nearby galaxies which were serendipitously within the field of view of the HESS telescopes within a year of the supernova event. HESS cherenkov air-shower data collected between December 2003 and March 2015 were considered and compared to recent catalogs. Nine candidate supernovae were identified and analysed. No significant emission from these supernovae has been found, and upper limits for their very high energy emission are reported.