Precise mass measurements for the double neutron star system J1829+2456

TL;DR

This paper reports precise measurements of the masses and proper motion of the double neutron star system J1829+2456, providing insights into its formation and kinematic properties.

Contribution

The study provides the first precise individual mass measurements and proper motion for PSR J1829+2456, enhancing understanding of neutron star binary evolution.

Findings

Neutron star masses are 1.306 and 1.299 solar masses.

Proper motion indicates a space velocity of approximately 49 km/s.

System characteristics suggest formation via a low-kick, symmetric supernova.

Abstract

PSR J1829+2456 is a radio pulsar in a relativistic binary system with another neutron star. It has a rotational period of 41 ms and a mildly eccentric ($e = 0.14$) 28-hr orbit. We have continued its observations with the Arecibo radio telescope and have now measured the individual neutron star masses of this system. The pulsar and companion masses are $1.306\,\pm\,0.007\,M_{\odot}$ and $1.299\,\pm\,0.007\,M_{\odot}$ (2$\sigma$ - 95% confidence, unless stated otherwise), respectively. We have also measured the proper motion for this system and used it to estimate a space velocity of 49$^{+77}_{-30}$ km s$^{-1}$ with respect to the local standard of rest. The relatively low values for companion mass, space velocity and orbital eccentricity in this system make it similar to other double neutron star systems in which the second-formed neutron star is thought to have formed in a low-kick, low mass-loss, symmetric supernova.