2021/02/15 by Bei You, Yuoli Tuo, Chengzhe Li +123
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Binary number #Black hole (networking) #Corona (planetary geology) #Coronal hole #Coronal loop #Coronal plane #Radiation #Reflection (computer programming) #astro-ph.GA #astro-ph.HE
paper · pdf · doi:10.1038/s41467-021-21169-5
11 pages, 5 figures; published in Nature Communications; An artist's impression of Figure 5 is updated here, and the animation is available at http://youbei.work/research/
openalex publication_date 2021/02/15 · openalex created_date 2021/03/01 · arxiv created 2021/03/10 · arxiv updated 2021/03/11 · openalex updated_date 2026/08/06
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.