Revise thermal winds of remnant neutron stars in gamma-ray bursts

TL;DR

This paper proposes a new model for gamma-ray burst emission involving a neutron star remnant and delayed accretion disk formation, explaining observational constraints from GW170817/GRB 170817A.

Contribution

It introduces a novel scenario where neutrino absorption delays disk formation, affecting thermal emission and providing insights into neutron star cooling after mergers.

Findings

Neutrino absorption delays accretion disk formation.

Thermal emission from the neutron star may be detectable post-merger.

The model aligns with observed delays in GW170817/GRB 170817A.

Abstract

It seems that the wealth of information revealed by the multi-messenger observations of the binary neutron star (NS) merger event, GW170817/GRB 170817A/kilonova AT2017gfo, places irreconcilable constraints to models of the prompt emission of this gamma-ray burst (GRB). The observed time delay between the merger of the two NSs and the trigger of the GRB and the thermal tail of the prompt emission can hardly be reproduced by these models simultaneously. We argue that the merger remnant should be an NS (last for, at least, a large fraction of 1s), and that the difficulty can be alleviated by the delayed formation of the accretion disk due to the absorption of high-energy neutrinos emitted by the NS and the delayed emergence of an effective viscous in the disk. Further, we extend the consideration of the effect of the energy deposition of neutrinos emitted from the NS. If the NS is the central object of a GRB with a distance and duration similar to that of GRB 170817A, thermal emission of the thermal bubble inflated by the NS after the termination of accretion may be detectable. If our scenario is verified, it would be of interest to investigate the cooling of nascent NSs.