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arXiv · 2503.01223

NICER, NuSTAR and Insight-HXMT views to the newly discovered black hole X-ray binary Swift J1727.8--1613

Jing-Qiang Peng·Shu Zhang·Qing-Cang Shui·Shuang-Nan Zhang·Ling-Da Kong·Yu-Peng Chen·Peng-Ju Wang·Long Ji·Jin-Lu Qu·Lian Tao·Ming-Yu Ge·Zhi Chang·Jian Li·Zhao-sheng Li·Zhuo-Li Yu·Zhe Yan
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Abstract

Swift J1727.8--1613 is a black hole X-ray binary newly discovered in 2023. We perform spectral analysis with simultaneous Insight-HXMT, NICER and NuSTAR observations when the source was approaching to the hard intermediate state. Such a joint view reveals an additional hard component apart from the normally observed hard component with reflection in the spectrum, to be distinguished from the usual black hole X-ray binary systems. By including this extra component in the spectrum, we have measured a high spin of $0.98^{+0.02}_{-0.07}$ and an inclination of around $40^{+1.2}_{-0.8}$ degrees, which is consistent with NICER results reported before. However, we find that the additional spectral component can not be exclusively determined due to the model degeneracy. Accordingly, a possible jet/corona configuration is adjusted to account for the spectral fitting with different model trials. The extra component may originate either from a relativistic jet or a jet base/corona underneath a slow jet.

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Jing-Qiang Peng, Shu Zhang, Qing-Cang Shui, Shuang-Nan Zhang, Ling-Da Kong, Yu-Peng Chen, Peng-Ju Wang, Long Ji, Jin-Lu Qu, Lian Tao, Ming-Yu Ge, Zhi Chang, Jian Li, Zhao-sheng Li, Zhuo-Li Yu, Zhe Yan. 2025-03-03. NICER, NuSTAR and Insight-HXMT views to the newly discovered black hole X-ray binary Swift J1727.8--1613. https://doi.org/10.3847/2041-8213%2Fad17ca

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