2025/09/25 by Shanshan Weng, Weng, Shan-Shan, Xiaotian Xu +15
Earth and Planetary Sciences · Physics and Astronomy · #FOS: Physical sciences #Gamma-ray bursts and supernovae #Geophysics and Gravity Measurements #High Energy Astrophysical Phenomena (astro-ph.HE) #Pulsars and Gravitational Waves Research
paper · pdf · doi:10.48550/arxiv.2509.21103
openalex publication_date 2025/09/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
X-ray pulsars (XRPs) consist of a magnetized neutron star (NS) and an optical donor star. The NS accretes matter from the donor star producing pulsed X-ray emission. In most cases the donor stars are Be stars, and accretion is episodic, that is, the NSs are generally X-ray dim, but occasionally experience outbursts. Here, we carry out a statistical study with the X-ray monitoring data, and obtain strong correlations between the spin periods of the NSs and the outburst parameters for the first time. We show that XRPs containing faster rotating NSs tend to display more violent eruptions. In addition, pulsating ultraluminous X-ray sources in nearby galaxies follow the similar relationship. We demonstrate that most of these systems are close to the spin equilibrium, and that brighter pulsars have acquired more angular momentum by accreting matter from their companion stars, resulting in faster rotating NSs.