Observations of a black hole x-ray binary indicate formation of a magnetically arrested disk

• 成果类型: Article
• 署名作者: You, Bei; Cao, Xinwu; Yan, Zhen; Hameury, Jean-Marie; Czerny, Bozena; Wu, Yue; Xia, Tianyu; Sikora, Marek; Zhang, Shuang-Nan; Du, Pu; Zycki, Piotr T.
• 署名单位: Wuhan University; Zhejiang University; Chinese Academy of Sciences; Shanghai Astronomical Observatory, CAS; Universites de Strasbourg Etablissements Associes; Universite de Strasbourg; Polish Academy of Sciences; Center for Theoretical Physics - Polish Academy of Sciences; Nanjing University; Nanjing University; Chinese Academy of Sciences; University of Science & Technology of China, CAS; Chinese Academy of Sciences; University of Science & Technology of China, CAS; Polish Academy of Sciences; Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences; Chinese Academy of Sciences; Institute of High Energy Physics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-9445
• DOI: 10.1126/science.abo4504
• 发表日期: 2023-09-01
• 页码: 961-964
• 关键词: 3-dimensional magnetohydrodynamic simulations; advection-dominated accretion; FLOWS; FIELDS; energy; state; jets; evaporation; transients; outbursts

摘要

Accretion of material onto a black hole drags any magnetic fields present inwards, increasing their strength. Theory predicts that sufficiently strong magnetic fields can halt the accretion flow, producing a magnetically arrested disk (MAD). We analyzed archival multiwavelength observations of an outburst from the black hole x-ray binary MAXI J1820+070 in 2018. The radio and optical fluxes were delayed compared with the x-ray flux by about 8 and 17 days, respectively. We interpret this as evidence for the formation of a MAD. In this scenario, the magnetic field is amplified by an expanding corona, forming a MAD around the time of the radio peak. We propose that the optical delay is due to thermal viscous instability in the outer disk.