Could a multi-PeV neutrino event have as origin the internal shocks inside the GRB progenitor star?

TL;DR

This paper investigates whether internal shocks inside GRB progenitor stars can produce the multi-PeV neutrinos detected by IceCube, focusing on specific conditions in Wolf-Rayet and blue supergiant stars.

Contribution

It explores the parameter space under which internal shocks in GRB progenitors can generate the observed high-energy neutrinos, linking astrophysical models with IceCube data.

Findings

Internal shocks in WR and BSG stars can produce multi-PeV neutrinos.

Neutrino production is favored for specific luminosities and shock radii.

High-energy neutrinos could originate from relatively low-luminosity GRBs.

Abstract

The IceCube Collaboration initially reported the detection of 37 extraterrestrial neutrinos in the TeV - PeV energy range. The reconstructed neutrino events were obtained during three consecutive years of data taking, from 2010 to 2013. Although these events have been discussed to have an extragalactic origin, they have not been correlated to any known source. Recently, the IceCube Collaboration reported a neutrino-induced muon event with energy of $2.6\pm0.3$ PeV which corresponds to the highest event ever detected. Neither the reconstructed direction of this event (J2000.0), detected on June 11 2014 at R.A.=110$^\circ$.34, Dec.=11$^\circ$.48 matches with any familiar source. Long gamma-ray bursts (lGRBs) are usually associated with the core collapse of massive stars leading relativistic-collimated jets inside stars with high-energy neutrino production. These neutrinos have been linked to the 37 events previously detected by IceCube experiment. In this work, we explore the conditions and values of parameters so that the highest neutrino recently detected could be generated by proton-photon and proton-hadron interactions at internal shocks inside lGRB progenitor star and then detected in IceCube experiment. Considering that internal shocks take place in a relativistic collimated jet, whose (half) opening angle is $\theta_0\sim$ 0.1, we found that lGRBs with total luminosity $L\lesssim 10^{48}$ erg/s and internal shocks on the surface of progenitors such as Wolf-Rayet (WR) and blue super giant (BSG) stars favor this multi-PeV neutrino production, although this neutrino could be associated to $L\sim 10^{50.5}$ ($\sim 10^{50}$) erg/s provided that the internal shocks occur at $\sim 10^9$ ($\sim 10^{10.2}$) cm for a WR (BSG).