Nine-hour X-ray quasi-periodic eruptions from a low-mass black hole galactic nucleus
G. Miniutti, R. D. Saxton, M. Giustini, K. D. Alexander, R. P. Fender, I. Heywood, I. Monageng, M. Coriat, A. K. Tzioumis, A. M. Read, C. Knigge, P. Gandhi, M. … 展开作者
G. Miniutti, R. D. Saxton, M. Giustini, K. D. Alexander, R. P. Fender, I. Heywood, I. Monageng, M. Coriat, A. K. Tzioumis, A. M. Read, C. Knigge, P. Gandhi, M. L. Pretorius, B. Agís-González
备注：
Authors' version of a Letter published on-line in Nature on September 11, 2019. Includes Methods and Extended Data. 43 pages, 3 tables and 10 figures
In the past two decades, high amplitude electromagnetic outbursts have been detected from dormant galaxies and often attributed to the tidal disruption of a star by the central black hole. X-ray emission from the Seyfert 2 galaxy GSN 069 (2MASX J01190869-3411305) at redshift z = 0.018 was first detected in 2010 July and implies an X-ray brightening of more than a factor of 240 over ROSAT observations performed 16 years earlier. The emission has smoothly decayed over time since 2010, possibly indicating a long-lived tidal disruption event. The X-ray spectrum is ultra-soft and can be described by accretion disc emission with luminosity proportional to the fourth power of the disc temperature during long-term evolution. Here we report observations of X-ray quasi-periodic eruptions from the nucleus of GSN 069 over the course of 54 days, 2018 December onwards. During these eruptions, the X-ray count rate increases by up to two orders of magnitude with event duration of just over 1 hour and recurrence time of about 9 hours. These eruptions are associated with fast spectral transitions between a cold and a warm phase in the accretion flow around a low-mass black hole (of approximately 4x10$^5$ solar masses) with peak X-ray luminosity of ~ 5x10$^{42}$ ergs per second. The warm phase has a temperature of about 120 eV, reminiscent of the typical soft X-ray excess, an almost universal thermal-like feature in the X-ray spectra of luminous active nuclei. If the observed properties are not unique to GSN 069, and assuming standard scaling of timescales with black hole mass and accretion properties, typical active galactic nuclei with more massive black holes can be expected to exhibit high-amplitude optical to X-ray variability on timescales as short as months or years.
Discovery of crested quasi-periodic eruptions following the most luminous SRG/eROSITA tidal disruption event
Max-Planck-Institut für extraterrestrische Physik（马克斯·普朗克地外物理研究所）；Excellence Cluster ORIGINS（ORIGINS 卓越集群）；School of Physics and Astronomy, Tel Aviv University（特拉维夫大学物理与天文学学院）；Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology（麻省理工学院卡弗里天体物理学与空间研究研究所）；Centro de Astrobiologia (CAB), CSIC-INTA（CSIC-INTA 天体生物学中心）；European Southern Observatory（欧洲南方天文台）
X-rays from shock-heated gas in recurrent-nova remnants: Nested nova shells in a structured circumstellar medium
Instituto Nacional de Astrofísica, Óptica y Electrónica（墨西哥国家天体物理学、光学和电子学研究所）；Astronomical Institute of the Czech Academy of Sciences（捷克科学院天文研究所）；Tartu Observatory, University of Tartu（塔尔图大学塔尔图天文台）
A Unified Timescale Relation for Quasi-Periodic Eruptions and Repeated Nuclear Transients
University of Science and Technology of China（中国科学技术大学）；Guizhou University（贵州大学）；Institute of Deep Space Sciences, Deep Space Exploration Laboratory（深空科学研究所，深空探测实验室）
Two-body relaxation in the EMRI-TDE disk model for Quasi Periodic Eruptions
Università degli Studi di Milano-Bicocca（米兰比可卡大学）；INFN, Sezione di Milano-Bicocca（意大利国家核物理研究所米兰比可卡分部）；INAF - Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）
Radiation-hydrodynamics of star-disc collisions for quasi-periodic eruptions
Institute of Physics of the Czech Academy of Sciences（捷克科学院物理研究所）；Centre for Astrophysics and Cosmology, University of Nova Gorica（新戈里察大学天体物理学与宇宙学中心）；School of Physics and Astronomy & Institute for Gravitational Wave Astronomy, University of Birmingham（伯明翰大学物理与天文学学院及引力波天文研究所）
