The extreme coronal line emitter AT 2022fpx: Varying optical polarization properties and late-time X-ray flare
Karri I. I. Koljonen, Ioannis Liodakis, Elina Lindfors, Kari Nilsson, Thomas M. Reynolds, Panos Charalampopoulos, Konstantinos Kouroumpatzakis, Callum McCall, H… 展开作者
Karri I. I. Koljonen, Ioannis Liodakis, Elina Lindfors, Kari Nilsson, Thomas M. Reynolds, Panos Charalampopoulos, Konstantinos Kouroumpatzakis, Callum McCall, Helen E. Jermak, Iain A. Steele, Juan Carbajo-Hijarrubia
备注：
13 pages, 9 figures, 1 table. This article has been accepted for publication in MNRAS published by Oxford University Press on behalf of the Royal Astronomical Society. Updated to match the accepted version
本文通过多波段光学偏振、光谱及光紫外/X 射线监测研究 TDE 候选体 AT 2022fpx，揭示其极端冕线、低偏振变化、偏振角旋转和延迟 X 射线耀发。
摘要：
超大质量黑洞会撕碎途经的恒星，产生被称为潮汐瓦解事件（TDE）的爆发。TDE 最近因其独特的动力学和辐射过程而受到关注，但这些过程仍未被充分理解。特别是所谓的光学 TDE，由于它们往往表现出来自吸积盘的延迟或被遮蔽的 X 射线辐射，使其即时辐射的起源尚不清楚，因而备受关注。本文介绍了对近期 TDE 候选体 AT 2022fpx 的多波段光学偏振观测和光学光谱观测，以及光学、紫外和 X 射线监测观测。AT 2022fpx 的光学光谱显示出 Bowen 荧光以及高电离铁发射线，这些是极端冕线发射体的特征。此外，该源在爆发峰值处表现出可变但低偏振的连续谱辐射，并且偏振角发生明显旋转。在衰减阶段、爆发峰值后约 250 天观测到的 X 射线辐射呈耀发状，但与恒温黑体辐射相符。整体爆发衰减比典型 TDE 更慢，更类似于在 Bowen 荧光耀发中看到的衰减。这些观测表明，AT 2022fpx 可能是连接不同长寿命 TDE 情景的关键源。其独特特征，如极端冕线发射、可变偏振和延迟 X 射线耀发，可归因于外激波情景或环绕超大质量黑洞的团块环面。进一步研究，尤其是在多波段观测背景下的研究，对于充分理解这些引人入胜的天体物理事件的动力学和辐射机制至关重要。
英文摘要：
Supermassive black holes disrupt passing stars, producing outbursts called tidal disruption events (TDEs). TDEs have recently gained attention due to their unique dynamics and emission processes, which are still not fully understood. Especially, the so-called optical TDEs, are of interest as they often exhibit delayed or obscured X-ray emission from the accretion disk, making the origin of the prompt emission unclear. In this paper, we present multiband optical polarization observations and optical spectrometry of a recent TDE candidate AT 2022fpx, alongside monitoring observations in optical, ultraviolet and X-rays. The optical spectra of AT 2022fpx show Bowen fluorescence as well as highly-ionized iron emission lines, which are characteristic of extreme coronal line emitters. Additionally, the source exhibits variable but low-polarized continuum emission at the outburst peak, with a clear rotation of the polarization angle. X-ray emission observed approximately 250 days after the outburst peak in the decay appear flare-like but is consistent with constant temperature black-body emission. The overall outburst decay is slower than for typical TDEs, and resembles more the ones seen from Bowen fluorescence flares. These observations suggest that AT 2022fpx could be a key source in linking different long-lived TDE scenarios. Its unique characteristics, such as extreme coronal line emission, variable polarization, and delayed X-ray flare, can be attributed to the outer shock scenario or a clumpy torus surrounding the supermassive black hole. Further studies, especially in the context of multi-wavelength observations, are crucial to fully understand the dynamics and emission mechanisms of these intriguing astrophysical events.
AT 2018dyk: tidal disruption event or active galactic nucleus? Follow-up observations of an extreme coronal line emitter with the Dark Energy Spectroscopic Instrument
通过暗能量光谱仪后续观测和宿主星系分析，确认 AT 2018dyk 是发生在富气体环境中的潮汐瓦解事件，并发现此类 TDE 的中红外特性与局部环境物质含量及密度相关。
Early results in the search for extreme coronal line emitters with the Dark Energy Spectroscopic Instrument
University of Southampton（南安普顿大学）；Institute of Cosmology and Gravitation, University of Portsmouth（朴茨茅斯宇宙学与引力研究所）；American Museum of Natural History（美国自然历史博物馆）；University of California, Berkeley（加州大学伯克利分校）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；Boston University（波士顿大学）；University of Rochester（罗切斯特大学）
VLASS tidal disruption events with optical flares II: discovery of two TDEs with intermediate width Balmer emission lines and connections to the ambiguous extreme coronal line emitters
Discovery of Quasi-periodic Eruptions in the Tidal Disruption Event and Extreme Coronal Line Emitter AT2022upj: implications for the QPE/TDE fraction and a connection to ECLEs
The Radio Properties of Extreme Coronal Line Emitters: Constraints on the Sub-parsec Environment
University of Arizona（亚利桑那大学）；University of Utah（犹他大学）；Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）；University of California, Berkeley（加利福尼亚大学伯克利分校）；Stanford University（斯坦福大学）
ATLAS22kjn (AT 2022fpx): A Coronal Line Emitter with an Early Light Curve Bump and Mid-Infrared Dust Echo
University of Illinois（伊利诺伊大学）；Institute for Astronomy, University of Hawai‘i（夏威夷大学天文研究所）；School of Physics, University of Melbourne（墨尔本大学物理学院）；The Ohio State University（俄亥俄州立大学）；Texas Tech University（德克萨斯理工大学）；Peking University（北京大学）；National Astronomical Observatories, Chinese Academy of Science（中国科学院国家天文台）
Kazan (Volga Region) Federal University（喀山（伏尔加沿岸）联邦大学）；Tatarstan Academy of Sciences（鞑靼斯坦科学院）；Space Research Institute, Russian Academy of Sciences（俄罗斯科学院空间研究所）；Max Planck Institute for Astrophysics（马克斯·普朗克天体物理研究所）
High-ionization coronal lines trace quasar-like activity in recently quenched galaxies at high redshift
Cosmic Dawn Center (DAWN)（宇宙黎明中心）；DTU Space, Technical University of Denmark（丹麦技术大学空间科学部）；École Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院）；INAF – Astronomical Observatory of Trieste（意大利国家天体物理研究所的里雅斯特天文台）；IFPU – Institute for Fundamental Physics of the Universe（宇宙基础物理研究所）
Constraining the contribution of Seyfert galaxies to the diffuse neutrino flux in light of point source observations
Max Planck Institute for Physics（马克斯·普朗克物理研究所）；TUM School of Natural Sciences, Technical University of Munich（慕尼黑工业大学自然科学院）；Institutt for fysikk, Norwegian University of Science and Technology（挪威科技大学物理系）；Max Planck Institute for Extraterrestrial Physics（马克斯·普朗克地外物理学研究所）
Back from the dead: AT2019aalc as a candidate repeating TDE in an AGN
Ruhr Astroparticle and Plasma Physics Center (RAPP Center)（鲁尔天体物理与等离子体物理中心）；Leiden Observatory, Leiden University（莱顿天文台，莱顿大学）；Deutsches Elektronen-Synchrotron (DESY)（德国电子同步辐射中心）；Institut fur Physik, Humboldt-Universität zu Berlin（柏林洪堡大学物理研究所）；Division of Physics, Mathematics, and Astronomy, California Institute of Technology（加州理工学院物理、数学和天文学系）；University of Maryland, Department of Astronomy（马里兰大学天文学系）；NASA Goddard Space Flight Center, Astrophysics Science Division（美国宇航局戈达德太空飞行中心天体物理学科学部）；Center for Research and Exploration in Space Science and Technology, NASA/GSFC（NASA/GSFC空间科学与技术研究探索中心）
Dynamic Accretion Disk-Corona Connection and Broad Fe K$α$ Variability in Mrk 766 Revealed by Time-Resolved High Resolution X-Ray Spectroscopic Analysis
University of Maryland Baltimore County（马里兰大学巴尔的摩分校）；School of Astrophysics, Presidency University（总统大学天体物理学院）；Inter-University Centre for Astronomy and Astrophysics (IUCAA)（大学间天文与天体物理中心）
