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arXiv · 1408.5162

Discovery of an ultracompact gamma-ray millisecond pulsar binary candidate

A. K. H. Kong·R. Jin·T. -C. Yen·C. P. Hu·C. Y. Hui·P. H. T. Tam·J. Takata·L. C. C. Lin·K. S. Cheng·S. M. Park·C. L. Kim
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Abstract

We report multi-wavelength observations of the unidentified Fermi object 2FGL J1653.6-0159. With the help of high-resolution X-ray observation, we have identified an X-ray and optical counterpart of 2FGL J1653.6-0159. The source exhibits a periodic modulation of 75 min in optical and possibly also in X-ray. We suggest that 2FGL J1653.6-0159 is a compact binary system with an orbital period of 75 min. Combining the gamma-ray and X-ray properties, 2FGL J1653.6-0159 is potentially a black widow/redback type gamma-ray millisecond pulsar (MSP). The optical and X-ray lightcurve profiles show that the companion is mildly heated by the high-energy emission and the X-rays are from intrabinary shock. Although no radio pulsation has been detected yet, we estimated that the spin period of the MSP is ~2ms based on a theoretical model. If pulsation can be confirmed in the future, 2FGL J1653.6-0159 will become the first ultracompact rotation-powered MSP.

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A. K. H. Kong, R. Jin, T. -C. Yen, C. P. Hu, C. Y. Hui, P. H. T. Tam, J. Takata, L. C. C. Lin, K. S. Cheng, S. M. Park, C. L. Kim. 2014-08-21. Discovery of an ultracompact gamma-ray millisecond pulsar binary candidate. https://doi.org/10.1088/2041-8205/794/2/l22

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