X-ray study of MSPs in globular clusters

We present a comprehensive census of X-ray millisecond pulsars (MSPs) in 29 Galactic globular clusters (GCs), including 68 MSPs with confirmed X-ray luminosities and 107 MSPs with X-ray upper limits. We compile previous X-ray studies of GC MSPs, and add new analyses of six MSPs (PSRs J1326-4728A, J1326-4728B, J1518+0204C, J1717+4308A, J1737-0314A, and J1807-2459A) discovered in five GCs. Their X-ray spectra are well described by a single blackbody model, a single power-law model, or a combination of them, with X-ray luminosities ranging from 1.9 * 10^30^ to 8.3 * 10^31^ erg/s. We find that most detected X-ray MSPs have luminosities between ~10^30^ and 3 * 10^31^ erg/s. Redback pulsars are a relatively bright MSP population with X-ray luminosities of ~2 * 10^31^ - 3 * 10^32^ erg/s. Black widows show a bimodal distribution in X-ray luminosities, with eclipsing black widows between ~7 * 10^30^ and 2 * 10^31^ erg/s, while the two confirmed non-eclipsing black widows are much fainter, with L_X_ of 1.5-3 * 10^30^ erg/s, suggesting an intrinsic difference in the populations. We estimate the total number of MSPs in 36 GCs by considering the correlation between the number of MSPs and stellar encounter rate in GCs, and suggest that between 600 and 1500 MSPs exist in these 36 GCs. Finally, we estimate the number of X-ray-detectable MSPs in the Galactic bulge, finding that 1-86 MSPs with L_X_ > 10^33^ erg/s, and 20-900 MSPs with L_X_ > 10^32^ erg/s should be detectable there.

Cone search capability for table J/MNRAS/511/5964/table10 (Determined X-ray 0.3-8 keV luminosities L_X_ of GC MSPs)

Cone search capability for table J/MNRAS/511/5964/tablea1 (Upper limits of X-ray luminosities for GC MSPs not eligible to specific X-ray spectral analysis)

Identifier
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/MNRAS/511/5964
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/511/5964
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/511/5964
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/MNRAS/511/5964
Provenance
Creator Zhao J.; Heinke C.O.
Publisher CDS
Publication Year 2025
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysical Processes; Astrophysics and Astronomy; Cosmology; Galactic and extragalactic Astronomy; Interdisciplinary Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy