Huntsman may need to be irradiated

TL;DR

This paper models the formation and evolution of huntsman millisecond pulsars with giant companions, highlighting the importance of irradiation effects in explaining their observed properties and suggesting their companions could be normal red giants.

Contribution

It introduces a model incorporating irradiation effects to explain huntsman pulsar binaries, expanding understanding of their companion stars.

Findings

Irradiation effects can explain the properties of huntsman pulsar binaries.

Companions may be normal red giant stars, not just red bump stars.

The model aligns with observed huntsman pulsars, including 1FGL J1417.7-4407 and PSR J1947-1120.

Abstract

Millisecond pulsars are rapidly rotating neutron stars, and it is now widely accepted that their extremely short rotation periods result from the accretion of material from a companion star. Binary evolution theory predicts that millisecond pulsars can have various types of companion stars. However, in observations, binary pulsars with giant companions, referred to as ``huntsman pulsars'', are extremely rare. Following the initial discovery of the first huntsman pulsar, 1FGL J1417.7-4407, a second huntsman millisecond pulsar binary, PSR J1947-1120, has been recently reported approximately a decade later. In this paper, we model the formation and evolution of two huntsman pulsars. Our model with the irradiation effect can explain the observed properties of huntsman pulsar binaries and suggests that if the irradiation effect is considered, the companion star may be a normal red giant star, rather than just a red bump star.