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arXiv · 2112.04790

GECAM detection of a bright type-I X-ray burst from 4U 0614+09: confirmation its spin frequency at 413 Hz

Abstract

One month after launching Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM), a bright thermonuclear X-ray burst from 4U~0614+09, was observed on January 24, 2021. We report the time-resolved spectroscopy of the burst and a burst oscillation detection at 413 Hz with a fractional amplitude 3.4\% (rms). This coincides with the burst oscillation previously discovered with \textit{Swift}/BAT \citep{Strohmayer2008}, and therefore confirms the spin frequency of this source. This burst is the brightest one in the normal bursts (except the superburst) ever detected from 4U~0614+09, which leads to an upper limit of distance estimation as 3.1 kpc. The folded light curve during the burst oscillation shows a multi-peak structure, which is the first case observed during a single burst oscillation in nonpulsating sources. The multi-peak profile could be due to additional harmonics of the burst oscillation, which is corresponding to several brighter/fainter spots at the stellar surface.

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Y. P. Chen, J. Li, S. L. Xiong, L. Ji, S. Zhang, W. X. Peng, R. Qiao, X. Q. Li, X. Y. Wen, L. M. Song, S. J. Zheng, X. Y. Song, X. Y. Zhao, Y. Huang, F. J. Lu, S. N. Zhang, S. Xiao, C. Cai, B. X. Zhang, Z. H. An, C. Chen, G. Chen, W. Chen, G. Q. Dai, Y. Q. Du, M. Gao, K. Gong, D. Y. Guo, Z. W. Guo, J. J. He, B. Li, C. Li, C. Y. Li, G. Li, J. H. Li, L. Li, Q. X. Li, X. B. Li, Y. G. Li, J. Liang, X. H. Liang, J. Y. Liao, J. C. Liu, X. J. Liu, Y. Q. Liu, Q. Luo, X. Ma, B. Meng, G. Ou, D. L. Shi, F. Shi, J. Y. Shi, G. X. Sun, X. L. Sun, Y. L. Tuo, C. W. Wang, H. Wang, H. Y. Wang, J. Wang, J. Z. Wang, P. Wang, Y. S. Wang, Y. X. Wang, X. Wen, H. Wu, S. L. Xie, Y. B. Xu, Y. P. Xu, W. C. Xue, S. Yang, M. Yao, J. Y. Ye, Q. B. Yi, C. M. Zhang, C. Y. Zhang, D. L. Zhang, Fan Zhang, Fei Zhang, H. M. Zhang, K. Zhang, P. Zhang, X. L. Zhang, Y. Q. Zhang, Z. Zhang, G. Y. Zhao, S. Y. Zhao, Y. Zhao, C. Zheng, X. Zhou, Y. Zhu. 2021-12-09. GECAM detection of a bright type-I X-ray burst from 4U 0614+09: confirmation its spin frequency at 413 Hz. https://doi.org/10.3847/1538-4357/ac7ff8

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