Two New Black Widow Millisecond Pulsars In M28

TL;DR

This paper reports the discovery of two new Black Widow millisecond pulsars in the globular cluster M28 using the MeerKAT telescope, highlighting the survey's enhanced sensitivity and potential for further discoveries.

Contribution

First detection of two Black Widow pulsars in M28 with MeerKAT, expanding known pulsar population and demonstrating survey advantages.

Findings

Two new Black Widow pulsars discovered in M28

Pulsars have low-mass companions and short orbital periods

Survey demonstrates MeerKAT's improved sensitivity for pulsar detection

Abstract

We report the discovery of two Black Widow millisecond pulsars in the globular cluster M28 with the MeerKAT telescope. PSR J1824$-$2452M (M28M) is a 4.78-ms pulsar in a $5.82\,$hour orbit and PSR J1824$-$2452N (M28N) is a 3.35-ms pulsar in a $4.76\,$hour orbit. Both pulsars have dispersion measures near $119.30\,$pc$\,$cm$^{-3}$ and have low mass companion stars ($\sim$$0.01-0.03\,$M$_\odot$), which do not cause strong radio eclipses or orbital variations. Including these systems, there are now five known black widow pulsars in M28. The pulsar searches were conducted as a part of an initial phase of MeerKAT's globular cluster census (within the TRAPUM Large Survey Project). These faint discoveries demonstrate the advantages of MeerKAT's survey sensitivity over previous searches and we expect to find additional pulsars in continued searches of this cluster.