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arXiv · 1910.08220

Insight-HXMT observation on 4U~1608--52: evolving spectral properties of a bright type-I X-ray burst

Y. P. Chen·S. Zhang·S. N. Zhang·L. Ji·L. D. Kong·A. Santangelo·J. L. Qu·F. J. Lu·T. P. Li·L. M. Song·Y. P. Xu·X. L. Cao·Y. Chen·C. Z. Liu·Q. C. Bu·C. Cai·Z. Chang·G. Chen·L. Chen·T. X. Chen·Y. B. Chen·W. Cui·W. W. Cui·J. K. Deng·Y. W. Dong·Y. Y. Du·M. X. Fu·G. H. Gao·H. Gao·M. Gao·M. Y. Ge·Y. D. Gu·J. Guan·C. C. Guo·D. W. Han·Y. Huang·J. Huo·S. M. Jia·L. H. Jiang·W. C. Jiang·J. Jin·B. Li·C. K. Li·G. Li·M. S. Li·W. Li·X. Li·X. B. Li·X. F. Li·Y. G. Li·Z. W. Li·X. H. Liang·J. Y. Liao G. Q. Liu·H. W. Liu·X. J. Liu·Y. N. Liu·B. Lu·X. F. Lu·Q. Luo·T. Luo·X. Ma·B. Meng·Y. Nang·J. Y. Nie·G. Ou·N. Sai·L. Sun·Y. Tan·L. Tao·Y. L. Tuo·C. Wang·G. F. Wang·J. Wang·W. S. Wang·Y. S. Wang·X. Y. Wen·B. Y. Wu·B. B. Wu·M. Wu·G. C. Xiao·S. Xiao·S. L. Xiong·J. W. Yang·S. Yang·Yang-Ji Yang·Yi-Jung Yang·Q. B. Yi·Q. Q. Yin·Y. You·A. M. Zhang·C. L. Zhang·C. M. Zhang·F. Zhang·H. M. Zhang·J. Zhang·T. Zhang·W. C. Zhang·W. Zhang·W. Z. Zhang·Yi. Zhang
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Abstract

The evidences for the influence of thermonuclear (type-I) X-ray bursts upon the surrounding environments in neutron star low-mass X-ray binaries (LMXB) were detected previously via spectral and timing analyses. Benefitting from a broad energy coverage of Insight-HXMT, we analyze one photospheric radius expansion (PRE) burst, and find an emission excess at soft X-rays. Our spectral analysis shows that, such an excess is not likely relevant to the disk reflection induced by the burst emission and can be attributed to an enhanced pre-burst/persistent emission. We find that the burst and enhanced persistent emissions sum up to exceed Eddington luminosity by $\sim$ 40 percentages. We speculate that the enhanced emission is from a region beyond the PRE radius, or through the Comptonization of the corona.

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Y. P. Chen, S. Zhang, S. N. Zhang, L. Ji, L. D. Kong, A. Santangelo, J. L. Qu, F. J. Lu, T. P. Li, L. M. Song, Y. P. Xu, X. L. Cao, Y. Chen, C. Z. Liu, Q. C. Bu, C. Cai, Z. Chang, G. Chen, L. Chen, T. X. Chen, Y. B. Chen, W. Cui, W. W. Cui, J. K. Deng, Y. W. Dong, Y. Y. Du, M. X. Fu, G. H. Gao, H. Gao, M. Gao, M. Y. Ge, Y. D. Gu, J. Guan, C. C. Guo, D. W. Han, Y. Huang, J. Huo, S. M. Jia, L. H. Jiang, W. C. Jiang, J. Jin, B. Li, C. K. Li, G. Li, M. S. Li, W. Li, X. Li, X. B. Li, X. F. Li, Y. G. Li, Z. W. Li, X. H. Liang, J. Y. Liao G. Q. Liu, H. W. Liu, X. J. Liu, Y. N. Liu, B. Lu, X. F. Lu, Q. Luo, T. Luo, X. Ma, B. Meng, Y. Nang, J. Y. Nie, G. Ou, N. Sai, L. Sun, Y. Tan, L. Tao, Y. L. Tuo, C. Wang, G. F. Wang, J. Wang, W. S. Wang, Y. S. Wang, X. Y. Wen, B. Y. Wu, B. B. Wu, M. Wu, G. C. Xiao, S. Xiao, S. L. Xiong, J. W. Yang, S. Yang, Yang-Ji Yang, Yi-Jung Yang, Q. B. Yi, Q. Q. Yin, Y. You, A. M. Zhang, C. L. Zhang, C. M. Zhang, F. Zhang, H. M. Zhang, J. Zhang, T. Zhang, W. C. Zhang, W. Zhang, W. Z. Zhang, Yi. Zhang. 2019-10-18. Insight-HXMT observation on 4U~1608--52: evolving spectral properties of a bright type-I X-ray burst. https://arxiv.org/abs/1910.08220

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