Young rotation-powered pulsars as ultra-luminous X-ray sources

Abstract

The aim of the present paper is to investigate a possible contribution of the rotation-powered pulsars and pulsar wind nebulae to the population of ultraluminous X-ray sources (ULXs). We first develop an analytical model for the evolution of the distribution function of pulsars over the spin period and find both the steady-state and the time-dependent solutions. Using the recent results on the X-ray efficiency dependence on pulsar characteristic age, we then compute the X-ray luminosity function (XLF) of rotation-powered pulsars. In a general case it has a broken power-law shape with a high luminosity cutoff, which depends on the distributions of the birth spin period and the magnetic field. Using the observed XLF of sources in the nearby galaxies and the condition that the pulsar XLF does not exceed that, we find the allowed region for the parameters describing the birth period distribution. We find that the mean pulsar period should be greater than 10-40 ms. These results are consistent with the constraints obtained from the X-ray luminosity of core-collapse supernovae. We estimate that the contribution of the rotation-powered pulsars to the ULX population is at a level exceeding 3 per cent. For a wide birth period distribution, this fraction grows with luminosity and above 10E40 erg/s pulsars can dominate the ULX population.

14 pages, 11 figures; MNRAS, in press

References in corpus (5)

• Super-critically accreting stellar-mass black holes as ultraluminous X-ray sources
• Identification of the X-Ray Thermal Dominant State in an Ultraluminous X-Ray Source in M82
• On the association of the ultraluminous X-ray sources in the Antennae galaxies with young stellar clusters
• Optical Counterparts of Ultra-Luminous X-ray Sources identified from Archival Hubble Space Telescope/WFPC2
• How rapidly do neutron stars spin at birth? Constraints from archival X-ray observations of extragalactic supernovae

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• Revisiting the Dynamical Case for a Massive Black Hole in IC10 X-1
• Nature of the Extreme Ultraluminous X-ray Sources
• Fast Radio Bursts counterparts in the scenario of supergiant pulses
• Searching for coherent pulsations in ultraluminous X-ray sources
• Discovery of a transient ultraluminous X-ray source in the elliptical galaxy M86
• The Great Pretenders Among the ULX Class