March 2025
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4 Reads
The Astrophysical Journal
To date, over 4000 pulsars have been detected. In this study, we identify 231 X-ray counterparts of Australia Telescope National Facility (ATNF) pulsars by performing a spatial cross match across the Chandra, XMM-Newton observational catalogs. This data set represents the largest sample of X-ray counterparts ever compiled, including 98 normal pulsars (NPs) and 133 millisecond pulsars (MSPs). Based on this significantly expanded sample, we re-establish the correlation between X-ray luminosity and spin-down power, given by L X ∝ E ̇ 0.85 ± 0.05 across the whole X-ray band. The strong correlation is also observed in hard X-ray band, while in soft X-ray band there is no significant correlation. Furthermore, L X shows a strong correlation with spin period and characteristic age for NPs. For the first time, we observe a strongly positive correlation between L X and the light cylinder magnetic field ( B lc ) for MSPs, with both NPs and MSPs following the relationship L X ∝ B lc 1.14 , consistent with the outer-gap model of pulsars that explains the mechanism of X-ray emission. Additionally, we investigate potential X-ray counterparts for Galactic Plane Pulsar Snapshot pulsars, finding a lower likelihood of detection compared to ATNF pulsars.