A binary origin of ultra-long period radio pulsars

TL;DR

This paper proposes a binary evolution model where neutron stars in wide binaries spin down via wind accretion, and subsequent supernova disruption produces isolated ultra-long period pulsars, explaining some long-period radio transients.

Contribution

It introduces a new binary evolution pathway for ultra-long period pulsars involving wind accretion and supernova disruption, accounting for their long spin periods.

Findings

Spin periods range from less than 0.1 s to over 10^8 s.

Estimated formation rate in the Milky Way is about 10^{-6} per year.

Model explains some long-period radio transients.

Abstract

We propose a possible binary evolution model for the formation of ultra-long period pulsars (ULPPs). The model involves two key stages: first, a neutron star (NS) in wide binaries undergoes an effective spin-down phase through wind-fed accretion from its massive stellar companion; second, the supernova explosion of the companion leads to the disruption of the binary system, and produces two isolated compact stars. One of the them is the first-born, slowly rotating NSs, and our binary and spin evolution calculations show that the spin periods range from $\lesssim 0.1$ s to $\gtrsim 10^8$ s. This offers a possible formation channel for some of the long-period radio transients. We estimate that the formation rate of such systems in the Milky Way is approximately about $10^{-6}$ $\rm yr^{-1}$.