Extragalactic star-forming galaxies with hypernovae and supernovae as high-energy neutrino and gamma-ray sources: the case of the 10 TeV neutrino data

TL;DR

This paper explores how hypernovae and supernovae in extragalactic star-forming galaxies could produce high-energy neutrinos and gamma rays, aligning with recent IceCube and Fermi observations, and discusses the dominance of hypernovae in cosmic ray energy input.

Contribution

It presents a novel scenario where hypernovae significantly contribute to the diffuse high-energy neutrino and gamma-ray backgrounds, contrasting with previous models emphasizing supernovae.

Findings

Diffuse neutrino spectrum from hypernovae matches IceCube data.

Gamma-ray background compatible with Fermi observations.

Hypernova energy input likely dominates over supernovae in cosmic ray production.

Abstract

In light of the latest IceCube data, we discuss the implications of the cosmic ray energy input from hypernovae and supernovae into the Universe, and their propagation in the hosting galaxy and galaxy clusters or groups. The magnetic confinement in these environments may lead to efficient $pp$ collisions, resulting in a diffuse neutrino spectrum extending from PeV down to 10 TeV energies, with a spectrum and flux level compatible with that recently reported by IceCube. If the diffuse 10 TeV neutrino background largely comes from such the CR reservoirs, the corresponding diffuse gamma-ray background should be compatible with the recent \textit{Fermi} data. In this scenario, the CR energy input from hypernovae should be dominant over that of supernovae, implying that the starburst scenario does not work if the supernova energy budget is a factor of two larger than the hypernova energy budget. Thus, this strong case scenario can be supported or ruled out in near future.