Magnetic fileds of coalescing neutron stars and the luminosity function of short gamma-ray burst

TL;DR

This paper models the magnetic field distribution of coalescing neutron stars and links it to the luminosity function of short gamma-ray bursts, supporting their origin from neutron star mergers.

Contribution

It introduces a population synthesis approach to connect neutron star magnetic field evolution with gamma-ray burst luminosities, aligning theoretical models with observations.

Findings

Magnetic field distribution influences gamma-ray burst luminosity.

Log-normal initial magnetic fields match observed burst properties.

Magnetic effects impact gravitational wave signals.

Abstract

Coalescing neutron star binaries are believed to be the most reliable sources for ground-based detectors of gravitational waves and likely progenitors of short gamma-ray bursts. In the process of coalescence, magnetic fields of neutron stars can induce interesting observational manifestations and affect the form of gravitational wave signal. In this papaer we use the population synthesis method to model the expected distribution of neutron star magnetic fields during the coalescence under different assumptions on the initial parameters of neutron stars and their magnetic field evolution. We discuss possible elecotrmagnetic phenomena preceding the coalescence of magnetized neutron star binaries and the effect of magnetic field on the gravitational wave signal. We find that a log-normal (Gaussian in logarithms) distribution of the initial magnetic fields of neutron stars, which agrees with observed properties of radio pulsars, produces the distribution of the magnetic field energy during the coalescence that adequately describes the observed luminosity function of short gamma-ray bursts under different assumptions on the field evolution and initial parameters of neutron stars. This agreement lends further support to the model of coalescing neutron star binaries as progenitors of gamma-ray bursts.