Determining neutron star masses with weak microlensing

TL;DR

This paper proposes a novel method to determine neutron star masses by analyzing weak gravitational microlensing effects on background galaxies, offering insights into neutron star properties beyond binary systems.

Contribution

It introduces a new technique using surface brightness distortions from microlensing to measure isolated neutron star masses, expanding the tools for neutron star studies.

Findings

Identified a promising pulsar-background galaxy pair for mass measurement

Method applicable to future large-scale optical and radio surveys

Potential to reveal neutron star mass distribution and equation of state

Abstract

The masses of stars including stellar remnants are almost exclusively known from binary systems. In this work, we study gravitational microlensing of faint background galaxies by isolated neutron stars (pulsars). We show that the resulting surface brightness distortions can be used to determine the masses of neutron star. Due to different evolutionary histories, isolated neutron stars may have different masses from those in binary systems, and thus provide unique insight into their equation of states under extreme physical conditions. We search for existing pulsar catalogs and find one promising pair of a nearby pulsar and a background galaxy. This method will become more practical for the next generation optical and radio surveys and telescopes.