PSR J1947-1120: A New Huntsman Millisecond Pulsar Binary

TL;DR

The paper reports the discovery of PSR J1947-1120, a huntsman millisecond pulsar with a red giant companion, providing new insights into pulsar formation and binary evolution.

Contribution

It introduces the huntsman class of millisecond pulsars, confirmed through multi-wavelength observations, and explains their formation using stellar evolution models.

Findings

First huntsman pulsar discovered with a red giant companion.

Huntsman pulsars are explained as neutron star binaries with red giant secondaries.

Provides constraints on mass transfer efficiency during pulsar recycling.

Abstract

We present the discovery of PSR J1947-1120, a new huntsman millisecond pulsar with a red giant companion star in a 10.3 d orbit. This pulsar was found via optical, X-ray, and radio follow-up of the previously unassociated gamma-ray source 4FGL J1947.6-1121. PSR J1947-1120 is the second confirmed pulsar in the huntsman class and establishes this as a bona fide subclass of millisecond pulsar. We use MESA models to show that huntsman pulsars can be naturally explained as neutron star binaries whose secondaries are currently in the "red bump" region of the red giant branch, temporarily underfilling their Roche lobes and hence halting mass transfer. Huntsman pulsars offer a new view of the formation of typical millisecond pulsars, allowing novel constraints on the efficiency of mass transfer and recycling at an intermediate stage in the process.