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arXiv · 2603.10788

Mass measurements of the double neutron star system PSR J0641+0448

Z. L. Yang·J. L. Han·P. F. Wang·C. Wang·N. N. Cai·W. C. Jing·W. Q. Su·T. Wang·J. Xu·Yi Yan·D. J. Zhou
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Abstract

Pulsar timing of double neutron star (DNS) systems is one of the best methodologies to study the neutron star masses distribution. Here we report the discovery of a double neutron star system PSR J0641+0448 in the Five-hundred-meter Aperture Spherical radio Telescope (FAST) Galactic Plane Pulsar Snapshot (GPPS) survey. This pulsar has a 25.7 ms spin period and moves in a 3.73-days eccentric orbit with an eccentricity of 0.145. Using FAST observations, we obtained its phase-connected timing solution with periastron advance and Shapiro delay detected. Using $\chi^2$ analysis based on DDGR model, we constrain the pulsar mass to $1.319^{+0.021}_{-0.035}~M_\odot$, and the companion mass to $1.269^{+0.022}_{-0.016}~M_\odot$ with a 68.3\% confidence level. The low companion mass and mild orbital eccentricity is consistent with the correlation between neutron masses and orbital eccentricities.

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Z. L. Yang, J. L. Han, P. F. Wang, C. Wang, N. N. Cai, W. C. Jing, W. Q. Su, T. Wang, J. Xu, Yi Yan, D. J. Zhou. 2026-03-11. Mass measurements of the double neutron star system PSR J0641+0448. https://doi.org/10.3847/2041-8213%2Fae4801

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