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arXiv · 1912.05708

NICER X-ray Observations of Seven Nearby Rotation-Powered Millisecond Pulsars

S. Guillot·M. Kerr·P. S. Ray·S. Bogdanov·S. Ransom·J. S. Deneva·Z. Arzoumanian·P. Bult·D. Chakrabarty·K. C. Gendreau·W. C. G. Ho·G. K. Jaisawal·C. Malacaria·M. C. Miller·T. E. Strohmayer·M. T. Wolff·K. S. Wood·N. A. Webb·L. Guillemot·I. Cognard·G. Theureau
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Abstract

NICER observed several rotation-powered millisecond pulsars to search for or confirm the presence of X-ray pulsations. When broad and sine-like, these pulsations may indicate thermal emission from hot polar caps at the magnetic poles on the neutron star surface. We report confident detections ($\ge4.7\sigma$ after background filtering) of X-ray pulsations for five of the seven pulsars in our target sample: PSR J0614-3329, PSR J0636+5129, PSR J0751+1807, PSR J1012+5307, and PSR J2241-5236, while PSR J1552+5437 and PSR J1744-1134 remain undetected. Of those, only PSR J0751+1807 and PSR J1012+5307 had pulsations previously detected at the 1.7$\sigma$ and almost 3$\sigma$ confidence levels, respectively, in XMM-Newton data. All detected sources exhibit broad sine-like pulses, which are indicative of surface thermal radiation. As such, these MSPs are promising targets for future X-ray observations aimed at constraining the neutron star mass-radius relation and the dense matter equation of state using detailed pulse profile modeling. Furthermore, we find that three of the detected millisecond pulsars exhibit a significant phase offset between their X-ray and radio pulses.

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S. Guillot, M. Kerr, P. S. Ray, S. Bogdanov, S. Ransom, J. S. Deneva, Z. Arzoumanian, P. Bult, D. Chakrabarty, K. C. Gendreau, W. C. G. Ho, G. K. Jaisawal, C. Malacaria, M. C. Miller, T. E. Strohmayer, M. T. Wolff, K. S. Wood, N. A. Webb, L. Guillemot, I. Cognard, G. Theureau. 2019-12-12. NICER X-ray Observations of Seven Nearby Rotation-Powered Millisecond Pulsars. https://doi.org/10.3847/2041-8213/ab511b

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