An Insight-HXMT view of the mHz quasi-regular modulation phenomenon in the black hole X-ray binary 4U 1630-47
Creators: name: Yang, Zi-Xu
name: Zhang, Liang
name: Huang, Yue
name: Bu, Qingcui
name: Zhang, Zhen
name: Liu, He-Xin
name: Yu, Wei
name: Wang, Peng-Ju
name: Zhao, Q. C.
name: Tao, L.
name: Qu, Jin-Lu
name: Zhang, Shu
name: Zhang, Shuang-Nan
name: Song, Liming
name: Lu, Fangjun
name: Cao, Xuelei
name: Chen, Li
name: Cai, Ce
name: Chang, Zhi
name: Chen, Tianxian
name: Chen, Yong
name: Chen, Yupeng
name: Chen, Yibao
name: Cui, Weiwei
name: Ding, Guoqiang
name: Du, Yuanyuan
name: Gao, GuanHua
name: Gao, He
name: Ge, Mingyu
name: Gu, Yudong
name: Guan, Ju
name: Guo, Chengcheng
name: Han, Dawei
name: Huo, Jia
name: Jia, Shumei
name: Jiang, Weichun
name: Jin, Jing
name: Kong, Lingda
name: Li, Bing
name: Li, Gang
name: Li, Wei
name: Li, Xian
name: Li, Xufang
name: Li, Zhengwei
name: Li, Chengkui
name: Lin, Lin
name: Liu, Congzhan
name: Li, Tipei
name: Li, Xiaobo
name: Liang, Xiaohua
name: Liao, Jinyuan
name: Liu, Hongwei
name: Liu, Xiaojing
name: Lu, Xuefeng
name: Luo, Qi
name: Luo, Tao
name: Ma, Binyuan
name: Ma, Ruican
name: Ma, Xiang
name: Meng, Bin
name: Nang, Yi
name: Nie, Jianyin
name: Ou, Ge
name: Ren, Xiaoqin
name: Sai, Na
name: Song, Xinying
name: Sun, Liang
name: Tan, Ying
name: Tuo, Youli
name: Wang, Chen
name: Wang, Wenshuai
name: Wang, Lingjun
name: Wang, Yusa
name: Wang, Jieshuang
name: Wen, Xiangyang
name: Wu, Bobing
name: Wu, Baiyang
name: Wu, Mei
name: Xiao, Shuo
name: Xu, Yupeng
name: Xiong, Shaolin
name: Yang, Sheng
name: Yang, Yanji
name: Yi, Qibin
name: Yin, Qianqing
name: You, Yuan
name: Zhang, Bing
name: Zhang, Fan
name: Zhang, Hongmei
name: Zhang, Juan
name: Zhang, Wanchang
name: Zhang, Wei
name: Zhang, Binbin
name: Zhang, Peng
name: Zhang, Yifei
name: Zhang, Yuanhang
name: Zhao, Haisheng
name: Zhao, Xiaofan
name: Zheng, Shijie
name: Zhou, Dengke
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Here we report the spectral-timing results of the black hole X-ray binary 4U 1630-47 during its 2021 outburst using observations from the Hard X-ray Modulation Telescope. Type-C quasi-periodic oscillations (QPOs) in 1.6--4.2 Hz and quasi-regular modulation (QRM) near 60 mHz are detected during the outburst. The mHz QRM has a fractional rms of 10%--16% in the 8--35 keV energy band with a Q factor (frequency/width) of 2--4. Benefiting from the broad energy band of hxmt, we study the energy dependence of the 60 mHz QRM in 1--100 keV for the first time. We find that the fractional rms of the mHz QRM increases with photon energy, while the time lags of the mHz QRM are soft and decrease with photon energy. Fast recurrence of the mHz QRM, in a timescale of less than one hour, has been observed during the outburst. During this period, the corresponding energy spectra moderately change when the source transitions from the QRM state to the non-QRM state. The QRM phenomena also shows a dependence with the accretion rate. We suggest that the QRM could be caused by an unknown accretion instability aroused from the corona.