New Class of High-Energy Transients from Crashes of Supernova Ejecta with Massive Circumstellar Material Shells

TL;DR

This paper explores a new class of supernovae with dense circumstellar shells, proposing their collisions as potential sources of high-energy cosmic rays, neutrinos, and gamma rays, and suggests multi-messenger detection strategies.

Contribution

It introduces the idea that supernova ejecta colliding with massive CSM shells can accelerate cosmic rays and produce detectable high-energy neutrinos and gamma rays.

Findings

Potential detection of multi-TeV neutrinos and gamma rays from nearby supernovae.

Identification of supernovae with dense circumstellar shells as cosmic-ray accelerators.

Necessity for coordinated multi-messenger observational campaigns.

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 (~10^5-10^11 cm^-3) shells of circumstellar material (CSM) on 10^2-10^4 AU scales. We consider the collisions of the SN ejecta with these massive CSM shells as potential cosmic-ray (CR) accelerators. If ~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 <20-30 Mpc. A new type of coordinated multi-messenger search for such transients of duration ~1 - 10 months is required; these may give important clues to the physical origin of such SNe and to CR acceleration mechanisms.