Population synthesis of low-mass binaries with wind-accreting neutron stars

arXiv:2609.16782 · astro-ph.HE, astro-ph.SR · Submitted 2026-09-15 · Read on arXiv

astro-ph.HE, astro-ph.SR

Submitted: 2026-09-15

Updated: 2026-09-15

Comments: 15 pages, 5 figures, submitted to New Astronomy

Code: https://github.com/COSMIC-PopSynth/COSMIC

License: http://creativecommons.org/licenses/by/4.0/

The gist: We perform population synthesis modeling of neutron star binary systems containing a low-mass main-sequence companion underfilling its Roche lobe.

Terminology

Abstract

We perform population synthesis modeling of neutron star binary systems containing a low-mass main-sequence companion underfilling its Roche lobe. About 10 5 such systems are expected to exist in the Milky Way. In the majority of such systems, NSs are expected to start accreting the stellar wind matter within a few Gyr, resulting in the appearance of a dim X-ray source. The exact value of this fraction mainly depends on the efficiency of the propeller spin-down, properties of the stellar wind, and common envelope efficiency. Mostly, NSs in such systems are formed in electron capture supernovae. Thus, they obtain a low natal kick. Due to this, the center-of-mass velocities of such binaries are low, too. Only in the case of high common envelope efficiency (α CE 3), a few tens of long-lived high-velocity binaries can be produced in core-collapse supernovae.

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