Diffuse high energy neutrinos and cosmic rays from hyperflares of soft-gamma repeaters

TL;DR

This paper models the high-energy neutrino and cosmic ray emissions from hyperflares of Soft-Gamma Repeaters using the fireball model, finding their contribution to the neutrino background is minor compared to gamma-ray bursts.

Contribution

It provides the first detailed calculation of neutrino emission from SGR hyperflares within the fireball framework, comparing their impact to GRBs.

Findings

Hyperflares occur at a rate 20-100 Gpc$^{-3}$day$^{-1}$, exceeding GRB rates.

Neutrino contribution from hyperflares is less than 10% of that from GRBs.

Discusses potential cosmic ray emissions from hyperflares.

Abstract

We calculate the diffuse high energy (TeV - PeV) neutrino emission from hyperflares of Soft-Gamma Repeaters (SGRs), like the hyperflare risen from \astrobj{SGR 1806-20} on December 27 of 2004, within the framework of the fireball model. The fireball model for gamma-ray bursts (GRBs) can explain well the main features of this hyperflare and the subsequent multi-frequency terglow emission. The expected rate, $\sim 20-100$ Gpc$^{-3}$day$^{-1}$, of such hyperflares is well in excess of the GRBs rate. Our result shows that the contribution to the diffuse TeV-PeV neutrino background from such hyperflares is less than 10% of the contribution from GRBs. We also discuss the high energy cosmic rays (CRs) from these sources.