A Shapiro delay detection in the binary system hosting the millisecond pulsar PSR J1910-5959A

TL;DR

This paper reports the detection of the relativistic Shapiro delay in the binary pulsar PSR J1910-5959A, providing new insights into neutron star and white dwarf masses, and testing theoretical models of binary evolution.

Contribution

The study presents the first detection of Shapiro delay in this system, refining companion mass estimates and evaluating binary evolution models with observational data.

Findings

Companion mass Mc = 0.180±0.018Msun

Pulsar mass range 1.1Msun to 1.5Msun

Discrepancies in the Mp - Pb correlation predictions

Abstract

PSR J1910-5959A is a binary pulsar with a helium white dwarf companion located about 6 arcmin from the center of the globular cluster NGC6752. Based on 12 years of observations at the Parkes radio telescope, the relativistic Shapiro delay has been detected in this system. We obtain a companion mass Mc = 0.180+/-0.018Msun (1sigma) implying that the pulsar mass lies in the range 1.1Msun <= Mp <= 1.5Msun. We compare our results with previous optical determinations of the companion mass, and examine prospects for using this new measurement for calibrating the mass-radius relation for helium white dwarfs and for investigating their evolution in a pulsar binary system. Finally we examine the set of binary systems hosting a millisecond pulsar and a low mass helium white dwarf for which the mass of both stars has been measured. We confirm that the correlation between the companion mass and the orbital period predicted by Tauris & Savonije reproduces the observed values but find that the predicted Mp - Pb correlation over-estimates the neutron star mass by about 0.5Msun in the orbital period range covered by the observations. Moreover, a few systems do not obey the observed Mp - Pb correlation. We discuss these results in the framework of the mechanisms that inhibit the accretion of matter by a neutron star during its evolution in a low-mass X-ray binary.