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arXiv · 1210.7342

Chandra Observations of Black-Widow Pulsars

Peter Gentile·Maura McLaughlin·Mallory Roberts·Fernando Camilo·Jason Hessels·Matthew Kerr·Scott Ransom·Paul Ray·Ingrid Stairs
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Abstract

We describe the first X-ray observations of binary millisecond pulsars PSRs J0023+0923, J1810+1744, J2215+5135, and J2256-1024. All four are Fermi gamma-ray sources and three are 'black-widow' pulsars, with companions of mass < 0.1 solar masses. Data were taken using the Chandra X-Ray Observatory and covered a full binary orbit for each pulsar. Two pulsars, PSRs J2215+5135 and J2256-1024, show significant orbital variability and X-ray flux minima at the times of eclipses observed at radio wavelengths. This phenomenon is consistent with intrabinary shock emission characteristic of black-widow pulsars. The other two pulsars, PSRs J0023+0923 and J1810+1744, do not demonstrate significant variability, but are fainter than the other two sources. Spectral fits yield power-law indices that range from 1.4 to 2.3 and blackbody temperatures in the hundreds of eV. The spectrum for PSR J2215+5135 shows a significant hard X-ray component (41% of counts are above 2 keV), which is additional evidence for the presence of intrabinary shock emission.

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Peter Gentile, Maura McLaughlin, Mallory Roberts, Fernando Camilo, Jason Hessels, Matthew Kerr, Scott Ransom, Paul Ray, Ingrid Stairs. 2012-10-27. Chandra Observations of Black-Widow Pulsars. https://doi.org/10.1017/s1743921312024234

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