A Search for High-Energy Emission from the Remnant of Supernova 1181

Abstract

Over the previous millennium, only five Galactic supernovae were observed and recorded by contemporary astronomers, and their current-day counterparts subsequently identified. The remnants of four of these have all been very deeply studied, and ultimately detected, by TeV instruments after exposures of typically hundreds of hours. The measured TeV fluxes range from 1 Crab (by definition) down to 0.3% Crab. The location of the fifth supernova remnant tied to a historical record of its supernova (SN 1181) has never been studied at TeV energies. The reason for this is simple - the associated remnant was only identified as such in 2021. The remnant, Pa 30, is an unusual object whose properties are best explained as resulting from a Type Iax supernova explosion. These are a rare sub-type of Type Ia supernovae in which the merging white dwarfs are not fully destroyed by the supernova explosion, leading to a double-degenerate merger product colorfully described as a 'zombie star'. We will present the results of a search for TeV gamma-ray emission from Pa 30 with VERITAS.