You Bei, Tuo Yuoli, Li Chengzhe, Wang Wei, Zhang Shuang-Nan, Zhang Shu, Ge Mingyu, Luo Chong, Liu Bifang, Yuan Weimin, Dai Zigao, Liu Jifeng, Qiao Erlin, Jin Chichuan, Liu Zhu, Czerny Bozena, Wu Qingwen, Bu Qingcui, Cai Ce, Cao Xuelei, Chang Zhi, Chen Gang, Chen Li, Chen Tianxiang, Chen Yibao, Chen Yong, Chen Yupeng, Cui Wei, Cui Weiwei, Deng Jingkang, Dong Yongwei, Du Yuanyuan, Fu Minxue, Gao Guanhua, Gao He, Gao Min, Gu Yudong, Guan Ju, Guo Chengcheng, Han Dawei, Huang Yue, Huo Jia, Jia Shumei, Jiang Luhua, Jiang Weichun, Jin Jing, Jin Yongjie, Kong Lingda, Li Bing, Li Chengkui, Li Gang, Li Maoshun, Li Tipei, Li Wei, Li Xian, Li Xiaobo, Li Xufang, Li Yanguo, Li Zhengwei, Liang Xiaohua, Liao Jinyuan, Liu Congzhan, Liu Guoqing, Liu Hongwei, Liu Xiaojing, Liu Yinong, Lu Bo, Lu Fangjun, Lu Xuefeng, Luo Qi, Luo Tao, Ma Xiang, Meng Bin, Nang Yi, Nie Jianyin, Ou Ge, Qu Jinlu, Sai Na, Shang Rencheng, Song Liming, Song Xinying, Sun Liang, Tan Ying, Tao Lian, Wang Chen, Wang Guofeng, Wang Juan, Wang Lingjun, Wang Wenshuai, Wang Yusa, Wen Xiangyang, Wu Baiyang, Wu Bobing, Wu Mei, Xiao Guangcheng, Xiao Shuo, Xiong Shaolin, Xu Yupeng, Yang Jiawei, Yang Sheng, Yang Yanji, Yi Qibin, Yin Qianqing, You Yuan, Zhang Aimei, Zhang Chengmo, Zhang Fan, Zhang Hongmei, Zhang Juan, Zhang Tong, Zhang Wanchang, Zhang Wei, Zhang Wenzhao, Zhang Yi, Zhang Yifei, Zhang Yongjie, Zhang Yue, Zhang Zhao, Zhang Ziliang, Zhao Haisheng, Zhao Xiaofan, Zheng Shijie, Zhou Dengke, Zhou Jianfeng, Zhu Yuxuan, Zhu Yue
School of Physics and Technology, Wuhan University, Wuhan, PR China.
Astronomical Center, Wuhan University, Wuhan, PR China.
Nat Commun. 2021 Feb 15;12(1):1025. doi: 10.1038/s41467-021-21169-5.
A black hole X-ray binary produces hard X-ray radiation from its corona and disk when the accreting matter heats up. During an outburst, the disk and corona co-evolves with each other. However, such an evolution is still unclear in both its geometry and dynamics. Here we report the unusual decrease of the reflection fraction in MAXI J1820+070, which is the ratio of the coronal intensity illuminating the disk to the coronal intensity reaching the observer, as the corona is observed to contrast during the decay phase. We postulate a jet-like corona model, in which the corona can be understood as a standing shock where the material flowing through. In this dynamical scenario, the decrease of the reflection fraction is a signature of the corona's bulk velocity. Our findings suggest that as the corona is observed to get closer to the black hole, the coronal material might be outflowing faster.
当吸积物质升温时，黑洞X射线双星会从其日冕和吸积盘产生硬X射线辐射。在一次爆发期间，吸积盘和日冕会相互共同演化。然而，这种演化在几何结构和动力学方面仍不清楚。在此，我们报告了MAXI J1820+070中反射分数的异常下降，反射分数是照亮吸积盘的日冕强度与到达观测者的日冕强度之比，因为在衰减阶段观测到日冕变暗。我们提出了一个类似喷流的日冕模型，在该模型中，日冕可被理解为物质流经的驻激波。在这种动力学情形下，反射分数的下降是日冕整体速度的一个标志。我们的研究结果表明，随着观测到日冕更靠近黑洞，日冕物质的外流速度可能更快。
