Chandra and HST Observations of Radio-Selected (Wandering) Massive Black Hole Candidates in Dwarf Galaxies
eXtreme Gravity Institute, Department of Physics, Montana State University（蒙大拿州立大学）；Center for Astrophysics | Harvard & Smithsonian（哈佛-史密森天体物理中心）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）；Center for Astrophysics and Space Astronomy, Department of Astrophysical and Planetary Sciences, University of Colorado（科罗拉多大学）；Vanderbilt University（范德堡大学）
Megan R. Sturm, Amy E. Reines, Anne M. Lohfink, Akos Bogdan, Ralph Kraft, Daniel Stern, Thomas Connor, Jeremy Darling, Mallory Molina
备注：
21 pages, 4 Figures, 7 Tables, accepted for publication in The Astrophysical Journal
We present Chandra X-ray Observatory and Hubble Space Telescope (HST) follow-up observations of 12 dwarf galaxies from Reines et al. (2020) that are potential hosts of radio-selected active galactic nuclei (AGNs), eight of which are non-nuclear and possible ``wandering" black holes (BHs). Our multi-wavelength analysis indicates a heterogeneous sample with five radio sources detected at both X-ray and optical wavelengths within positional uncertainties and non-detections for the remaining objects. Of the radio objects detected in the X-ray/optical, three have multi-wavelength evidence for hosting nuclear massive BHs and one object is consistent with an extreme compact starburst. Only one of the off-nuclear radio sources has a significant optical counterpart and we present Palomar spectroscopy that identifies this object as a background AGN. We cannot definitively determine if the seven remaining off-nuclear radio sources are wandering massive BHs in the target dwarf galaxies or background AGNs, although the three sources with the largest offsets have compact radio cores detected with the Very Large Baseline Array and are consistent with expectations for background AGNs (Sargent et al 2022). Our HST sensitivity limits also allow for wandering massive BHs in the target dwarf galaxies that are hosted by stellar clusters with masses $\lesssim 10^6 M_\odot$.
Resolving the temporal evolution of M87 jet with $\lesssim0.1$-arcsec Chandra observations
Université Laval（拉瓦尔大学）；Center for Astrophysics — Harvard & Smithsonian（哈佛-史密森天体物理中心）；ICRAR, University of Western Australia（西澳大利亚大学 ICRAR）；Department of Physics, University of Maryland Baltimore County（马里兰大学巴尔的摩分校物理系）
利用 13 年 Chandra/HRC-I 数据，通过点扩散函数反卷积实现亚角秒级 X 射线分辨，揭示了 M87 喷流中 HST-1 的双成分结构及下游结的复杂形态，并发现 X 射线整体流量下降高达 84%，符合同步辐射冷却模型。
Hot, Photoionized X-ray Gas in Two Luminous Type 2 Quasars: Chandra-HST Evidence for a Wind-Driven Sequence
NASA Goddard Space Flight Center（NASA戈达德太空飞行中心）；The Catholic University of America（天主教大学）；Harvard-Smithsonian Center for Astrophysics（哈佛-史密森天体物理中心）；INAF Osservatorio Astronomico di Roma（意大利国家天体物理研究所罗马天文台）；Eureka Scientific, Inc.（尤里卡科学公司）；INAF - Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；Dipartimento di Fisica, Università di Trento（特伦托大学物理系）；Naval Research Laboratory（海军研究实验室）；AURA for ESA（欧洲空间局美国天文研究联盟）
Hubble Study of the Proper Motion of HST-1 in the Jet of M87
Villanova University（维拉诺瓦大学）；McGill University（麦吉尔大学）；Washington University in St. Louis（华盛顿大学圣路易斯分校）；Astronomical Observatory of the Jagiellonian University（亚盖隆大学天文台）
The discovery of lensed radio and X-ray sources behind the Frontier Fields cluster MACS J0717.5+3745 with the JVLA and Chandra
我们报告的高分辨率JVLA和钱德拉观测的HST前沿星系团MACS J0717.5+3745。MACS J0717.5+3745提供了任何已知星团中最大的连续放大区域，使其成为寻找透镜射电和X射线源的有希望的目标。利用高分辨率1.0-6.5 GHz JVLA成像，在A和B配置下，我们在HST成像覆盖的区域内探测到总共51个紧凑的射电源。在这个样本中，我们发现7个放大因子大于$2$的透镜源。这些来源都没有被确定为多重透镜。根据射电光度，这些来源中的大多数可能是恒星形成的星系，恒星形成率为10-50 M $_\odot$ yr $^{-1}$，位于$1 \lesssim z \lesssim 2$。两个透镜射电源也在星团的钱德拉图像中被检测到。这两个源很可能是活动星系核，因为它们的$2-10$ keV X射线光度是$\sim 10^{43-44}$ erg s $^{-1}$。从推导出的射电光度函数，我们发现的证据，在$0.6<z<2.0$的射电源的数量密度增加，相比，一个$z < 0.3$样本。我们的观测结果表明，透镜星系团的深射电成像可以用来研究恒星形成星系，恒星形成率低至$\sim10$ M $_{\odot}$ yr $^{-1}$，在宇宙恒星形成历史的高峰期。
High Resolution X-ray Spectroscopy of the Seyfert 1, Mrk 1040. Revealing the Failed Nuclear Wind with Chandra
本文报道了邻近的X射线明亮的Seyfert 1星系Mrk 1040中暖吸收体的高分辨X射线能谱。这些观测是在2013-2014年的时间框架内使用Chandra高能透射光栅进行的，总曝光量为200 ks。大量的吸收线从Ne，Mg和Si的检测从各种各样的电离状态。特别是，从Ne，Mg和Si的内K-壳层吸收线的检测，从F-样到Li-样离子的电荷状态，表明存在大量的低电离吸收气体，由陡峭的软X射线连续体照射。观测结果表明至少有3个热吸收组分，电离参数在$\logξ= 0-2$范围内，柱密度为$N_{\rm H} =1.5-4.0 \times 10^{21}$ cm $^{-2}$。速度剖面表明，吸收气体的流出速度很低，在Mrk 1040系统速度的$\pm100$ km s $^{-1}$范围内，这表明任何流出的气体都可能在足够大的尺度上停滞在这个活动星系核中。温暖的吸收体很可能位于远离黑洞的地方，在原子核的300 pc范围内，并且在空间上与HST图像中看到的扩展窄线区域的发射相一致。铁K带光谱仅显示窄的发射线，6.4 keV处的Fe K $α$与康普顿厚pc级后处理气体的反射一致。
Merger-driven Fueling of Active Galactic Nuclei: Six Dual and Offset Active Galactic Nuclei Discovered with Chandra and Hubble Space Telescope Observations
