New class of high-energy transients from crashes of supernova ejecta with massive circumstellar material shells

Abstract

A new class of core-collapse supernovae (SNe) has been discovered in recent years by optical/infrared surveys; these SNe suggest the presence of one or more extremely dense ($\ensuremath{\sim}{10}^{5\ensuremath{-}11}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}3}$) shells of circumstellar material (CSM) on ${10}^{2\ensuremath{-}4}\text{ }\text{ }\mathrm{AU}$ scales. We consider the collisions of the SN ejecta with these massive CSM shells as potential cosmic-ray (CR) accelerators. If $\ensuremath{\sim}10%$ of the SN energy goes into CRs, multi-TeV neutrinos and/or GeV-TeV gamma rays almost simultaneous with the optical/infrared light curves are detectable for SNe at $\ensuremath{\lesssim}20--30\text{ }\text{ }\mathrm{Mpc}$. A new type of coordinated multimessenger search for such transients of duration $\ensuremath{\sim}1--10$ months is required; these may give important clues to the physical origin of such SNe and to CR acceleration mechanisms.