## QPOs and Orbital elements of X-ray binary 4U 0115+63 during the 2017 outburst observed by Insight-HXMT

18 Feb 2021  ·  Y. Z. Ding, W. Wang, P. Zhang, Q. C. Bu, C. Cai, X. L. Cao, C. Zhi, L. Chen, T. X. Chen, Y. B. Chen, Y. Chen, Y. P. Chen, W. W. Cui, Y. Y. Du, G. H. Gao, H. Gao, M. Y. Ge, Y. D. Gu, J. Guan, C. C. Guo, D. W. Han, Y. Huang, J. Huo, S. M. Jia, W. C. Jiang, J. Jin, L. D. Kong, B. Li, C. K. Li, G. Li, T. P. Li, W. Li, X. Li, X. B. Li, X. F. Li, Z. W. Li, X. H. Liang, J. Y. Liao, B. S. Liu, C. Z. Liu, H. X. Liu, H. W. Liu, X. J. Liu, F. J. Lu, X. F. Lu, Q. L., L. T., R. C. Ma, X. Ma, B. Meng, Y. Nang, J. Y. Nie, J. L. Qu, X. Q. Ren, N. Sai, L. M. Song, X. Y. Song, L. Sun, Y. Tan, L. Tao, Y. L. Tuo, L. J. Wang, P. 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, Y. P. Xu, R. J. Yang, S. Yang, Y. J. Yang, Q. B. Yi, Q. Q. Yin, Y. You, F. Zhang, H. M. Zhang, J. Zhang, P. Zhang, S. Zhang, S. N. Zhang, W. C. Zhang, W. Zhang, Y. F. Zhang, Y. H. Zhang, H. S. Zhao, X. F. Zhao, S. J. Zheng, Y. G. Zheng, D. K. Zhou ·

In this paper, we presented a detailed timing analysis of a prominent outburst of 4U 0115+63 detected by \textit{Insight}-HXMT in 2017 August. The spin period of the neutron star was determined to be $3.61398\pm 0.00002$ s at MJD 57978... We measured the period variability and extract the orbital elements of the binary system. The angle of periastron evolved with a rate of $0.048\pm0.003$ $yr^{-1}$. The light curves are folded to sketch the pulse profiles in different energy ranges. A multi-peak structure in 1-10 keV is clearly illustrated. We introduced wavelet analysis into our data analysis procedures to study QPO signals and perform a detailed wavelet analysis in many different energy ranges. Through the wavelet spectra, we report the discovery of a QPO at the frequency $\sim 10$ mHz. In addition, the X-ray light curves showed multiple QPOs in the period of $\sim 16-32$ s and $\sim 67- 200$ s. We found that the $\sim100$ s QPO was significant in most of the observations and energies. There exist positive relations between X-ray luminosity and their Q-factors and S-factors, while the QPO periods have no correlation with X-ray luminosity. In wavelet phase maps, we found that the pulse phase of $\sim 67- 200$ s QPO drifting frequently while the $\sim 16-32$ s QPO scarcely drifting. The dissipation of oscillations from high energy to low energy was also observed. These features of QPOs in 4U 0115+63 provide new challenge to our understanding of their physical origins. read more

PDF Abstract

# Code Add Remove Mark official

No code implementations yet. Submit your code now

# Categories

High Energy Astrophysical Phenomena