On the Formation of the Double Neutron Star Binary PSR J1846-0513

TL;DR

This paper investigates the formation and evolution of the double neutron star system PSR J1846-0513, combining observational constraints with detailed modeling of its progenitor system and supernova effects.

Contribution

It presents a comprehensive model of the system's formation, including progenitor characteristics and supernova asymmetries, based on new observational data and simulations.

Findings

Progenitor likely a neutron star-He star binary with specific mass range.

Initial orbit probably circular with a period around 0.5 days.

Supernova asymmetry contributes to the system's eccentricity.

Abstract

The double neutron star PSR J1846-0513 is discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Commensal Radio Astronomy FAST Survey. The pulsar is revealed to be harbored in an eccentric orbit with $e=0.208$ and orbital period of 0.613 days. The total mass of the system is constrained to be $2.6287(35)\rm{M}_{\odot}$, with a mass upper limit of $1.3455{\rm~M}_{\odot}$ for the pulsar and a mass lower limit of $1.2845{\rm~M}_{\odot}$ for the companion star. To reproduce its evolution history, we perform a 1D model for the formation of PSR J1846-0513 whose progenitor is assumed to be neutron star - helium (He) star system via MESA code. Since the large eccentricity is widely believed to originate from an asymmetric supernova explosion, we also investigate the dynamical effects of the supernova explosion. Our simulated results show that the progenitor of PSR J1846-0513 could be a binary system consisting of a He star of $3.3-4.0{\rm~M}_\odot$ and a neutron star in a circular orbit with an initial period of $\sim0.5$ days.