Microlensing pulsars

TL;DR

This paper explores the potential of pulsars acting as gravitational lenses in microlensing events towards the galactic bulge, emphasizing future observational prospects with FAST, SKA, and advanced optical telescopes.

Contribution

It introduces the idea of using pulsar microlensing as a novel method to measure pulsar masses and constrain the state of matter at supra-nuclear densities.

Findings

Lensing rate estimated at > 1 event per decade.

Future observations with FAST and SKA are promising for detecting microlensing pulsars.

Microlensing pulsar detection could provide insights into dense matter physics.

Abstract

We investigate the possibilities that pulsars act as the lens in gravitational microlensing events towards the galactic bulge or a spiral arm. Our estimation is based on expectant survey and observations of FAST (Five hundred meter Aperture Spherical Telescope) and SKA (Square Kilometer Array), and two different models of pulsar distribution are used. We find that the lensing rate is > 1 event/decade, being high enough to search the real events. Therefore, the microlensing observations focusing on pulsars identified by FAST or SKA in the future are meaningful. As an independent determination of pulsar mass, a future detection of microlensing pulsars should be significant in the history of studying pulsars, especially in constraining the state of matter (either hadronic or quark matter) at supra-nuclear densities. The observations of such events by using advanced optical facilities (e.g., the James Webb Space Telescope and the Thirty Meter Telescope) in future are highly suggested.