BASS XXXIX: Swift-BAT AGN with changing-look optical spectra
Matthew J. Temple, Claudio Ricci, Michael J. Koss, Benny Trakhtenbrot, Franz E. Bauer, Richard Mushotzky, Alejandra F. Rojas, Turgay Caglar, Fiona Harrison, Kyu… 展开作者
Matthew J. Temple, Claudio Ricci, Michael J. Koss, Benny Trakhtenbrot, Franz E. Bauer, Richard Mushotzky, Alejandra F. Rojas, Turgay Caglar, Fiona Harrison, Kyuseok Oh, Estefania Padilla Gonzalez, Meredith C. Powell, Federica Ricci, Rogério Riffel, Daniel Stern, C. Megan Urry
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14 pages, 7 figures, plus appendix. v2: updated references. Published in MNRAS
Changing-look (CL) AGN are unique probes of accretion onto supermassive black holes (SMBHs), especially when simultaneous observations in complementary wavebands allow investigations into the properties of their accretion flows. We present the results of a search for CL behaviour in 412 Swift-BAT detected AGN with multiple epochs of optical spectroscopy from the BAT AGN Spectroscopic Survey (BASS). 125 of these AGN also have 14-195 keV ultra-hard X-ray light-curves from Swift-BAT which are contemporaneous with the epochs of optical spectroscopy. Eight CL events are presented for the first time, where the appearance or disappearance of broad Balmer line emission leads to a change in the observed Seyfert type classification. Combining with known events from the literature, 21 AGN from BASS are now known to display CL behaviour. Nine CL events have 14-195 keV data available, and five of these CL events can be associated with significant changes in their 14-195 keV flux from BAT. The ultra-hard X-ray flux is less affected by obscuration and so these changes in the 14-195 keV band suggest that the majority of our CL events are not due to changes in line-of-sight obscuration. We derive a CL rate of 0.7-6.2 per cent on 10-25 year time-scales, and show that many transitions happen within at most a few years. Our results motivate further multi-wavelength observations with higher cadence to better understand the variability physics of accretion onto SMBHs.
BAT AGN Spectroscopic Survey XXI: The Data Release 2 Overview
BAT AGN光谱巡天（BASS）旨在提供一个高度完整的超大质量黑洞（SMBH）的关键物理参数普查，这些参数为本地活动星系核（AGN）（z<0.3）提供动力，包括它们的热光度，黑洞质量，吸积率和视线气体遮蔽，以及它们的宿主星系的独特属性（例如，恒星形成速率、质量和气体分数）。我们提出了一个概述的BASS数据发布2（DR 2），一个前所未有的光谱调查的光谱范围，分辨率和灵敏度，包括1449光学（3200-10000 A）和233近红外（1-2.5微米）光谱的最亮的858超硬X射线（14-195千电子伏）选择AGN在整个天空中，基本上所有的遮蔽水平。这个版本提供了一套非常完整的关键测量（发射线测量和中心速度色散），99.9%的测量红移和98%的黑洞质量估计（银河平面外的活动星系核）。BASS DR 2 AGN样本代表了对附近强大AGN的独特普查，在AGN的热光度、黑洞质量、爱丁顿比和遮蔽方面跨越了5个数量级。因此，公开的BASS DR 2样本和测量结果可以用来回答有关SMBH生长及其与宿主星系演化和局部宇宙反馈的联系的基本问题，以及有关SMBH物理学的公开问题。在这里，我们提供了一个简短的概述调查策略，关键的BASS DR 2测量，数据集和目录，以及科学亮点，从一系列的DR 2为基础的工作。
BASS. XXXVI. Constraining the Local Supermassive Black Hole - Halo Connection with BASS DR2 AGN
利用Swift/BAT活动星系核光谱巡天（BASS DR 2）的活动星系核（AGN）的聚类统计和光度函数，研究了局域宇宙中超大质量黑洞（SMBH）与其宿主暗物质晕之间的联系.通过正演模拟活动星系核活动到快照晕目录从N体模拟，我们测试的情况下，SMBH质量相关的暗物质（子）晕质量固定的恒星质量。我们比较这一模型缺乏这种相关性，恒星质量单独决定SMBH质量。我们发现，虽然这两个简单的模型能够在很大程度上再现的丰度和整体集群的活动星系核，黑洞质量与晕质量密切相关的模型是首选的数据由$1.8σ$。当包括一个独立的测量黑洞质量晕质量相关性，这个模型是首选的$4.6σ$。我们发现，与黑洞质量的聚类趋势可以进一步打破两种情况之间的退化，我们的首选模型再现测量的聚类差异1晕尺度之间的大，小黑洞质量。这些结果表明，晕结合能与超大质量黑洞的生长有着根本的联系。
BASS LV. Connecting X-ray variability with AGN physical properties and a new path to Cosmological distances
Università degli Studi Roma Tre（罗马第三大学）；INAF – Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿切里天文台）；European Space Agency (ESA), European Space Research and Technology Centre (ESTEC)（欧洲空间局欧洲空间研究与技术中心）；INAF – Osservatorio Astronomico di Roma（意大利国家天体物理研究所罗马天文台）；INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna（意大利国家天体物理研究所博洛尼亚天文与空间科学台）；Pontificia Universidad Católica de Chile, Instituto de Astrofísica（智利天主教大学天体物理研究所）；Cahill Center for Astronomy and Astrophysics, California Institute of Technology（加州理工学院凯尔天文学与天体物理学中心）；Frontier Research Institute for Interdisciplinary Sciences, Tohoku University（东北大学跨学科前沿研究院）
