Chandra X-ray spectroscopy of the focused wind in the Cygnus X-1 system III. Dipping in the low/hard state
Maria Hirsch, Natalie Hell, Victoria Grinberg, Ralf Ballhausen, Michael A. Nowak, Katja Pottschmidt, Norbert S. Schulz, Thomas Dauser, Manfred Hanke, Timothy R.… 展开作者
Maria Hirsch, Natalie Hell, Victoria Grinberg, Ralf Ballhausen, Michael A. Nowak, Katja Pottschmidt, Norbert S. Schulz, Thomas Dauser, Manfred Hanke, Timothy R. Kallman, Gregory V. Brown, Jörn Wilms
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19 pages, 15 figures, accepted for publication in A&A
We present an analysis of three Chandra High Energy Transmission Gratings observations of the black hole binary Cyg X-1/HDE 226868 at different orbital phases. The stellar wind that is powering the accretion in this system is characterized by temperature and density inhomogeneities including structures, or "clumps", of colder, more dense material embedded in the photoionized gas. As these clumps pass our line of sight, absorption dips appear in the light curve. We characterize the properties of the clumps through spectral changes during various dip stages. Comparing the silicon and sulfur absorption line regions (1.6-2.7 keV $\equiv$ 7.7-4.6 Å) in four levels of varying column depth reveals the presence of lower ionization stages, i.e., colder or denser material, in the deeper dip phases. The Doppler velocities of the lines are roughly consistent within each observation, varying with the respective orbital phase. This is consistent with the picture of a structure that consists of differently ionized material, in which shells of material facing the black hole shield the inner and back shells from the ionizing radiation. The variation of the Doppler velocities compared to a toy model of the stellar wind, however, does not allow us to pin down an exact location of the clump region in the system. This result, as well as the asymmetric shape of the observed lines, point at a picture of a complex wind structure.
XRISM High-Resolution X-ray Spectroscopy of Cygnus X-1 -- highly ionized Iron absorption structures
Rikkyo University（立教大学）；Lawrence Livermore National Laboratory（劳伦斯利弗莫尔国家实验室）；SRON Netherlands Institute for Space Research（荷兰空间研究所）；Cahill Center for Astronomy and Astrophysics, California Institute of Technology（加州理工学院凯尔天体物理学中心）；Department of Astronomy, University of Michigan（密歇根大学天文学系）；MIT Kavli Institute for Astrophysics and Space Research（麻省理工学院卡弗里天体物理与空间研究所）；Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA)（日本宇宙航空研究开发机构宇宙科学研究所）；NASA / Goddard Space Flight Center（美国宇航局戈达德太空飞行中心）
Chandra X-Ray Spectroscopy of the Focused Wind in the Cygnus X-1 System. II. The Nondip Spectrum in the Low/Hard State - Modulations with Orbital Phase
The statistical uncertainties on X-ray flux and spectral parameters from Chandra ACIS-I observations of faint sources: Application to the Cygnus OB2 Association
High Resolution X-ray Spectroscopy of the Nova-Like Cataclysmic Variable BZ Cam using Chandra HETG: Diagnosis of the ADAF-like (Advective) Hot Flow
Department of Astronomy and Space Sciences, Faculty of Science, Istanbul University（伊斯坦布尔大学理学院天文学与空间科学系）；Kadir Has University, Faculty of Engineering and Natural Sciences（卡迪尔哈斯大学工程与自然科学学院）；Lockheed Martin Solar and Astrophysics Laboratory（洛克希德·马丁太阳与天体物理实验室）
Probing Periodic and Aperiodic Variability of X-ray Sources in M31, M81 and Centaurus A with Chandra
School of Astronomy and Space Science, Nanjing University（南京大学天文与空间科学学院）；Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education（南京大学现代天文与天体物理教育部重点实验室）；INAF – Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）
Swift J174540.7-290015: a new accreting binary in the Galactic Center
我们报告的新的银河系中心（GC）的瞬态斯威夫特J174540.7-290015作为一个可能的低质量X射线双星（LMXB）位于只有16角秒从Sgr A* 的识别。在2016年2月6日的Swift GC监测期间检测到这种瞬变，它显示出与硬到软状态转变兼容的长期光谱变化。我们在2月26日用XMM-牛顿观测了35 ks的场，检测到软态的源，其特征是低水平的可变性和具有高能量尾部的软X射线热谱（通过INTEGRAL检测到高达~50 keV），典型的吸积中子星或黑洞。我们观察到：i）中性吸收物质的高柱密度，表明斯威夫特J174540.7-290015位于GC附近或之外; ii）亚太阳铁丰度，因此我们认为铁耗尽成尘埃颗粒。没有探测到FeK吸收线、蚀或倾斜，表明吸积盘是在低倾角下观测到的。无线电（VLA）观测没有发现任何与斯威夫特J174540.7-290015对应的无线电。用MPG/ESO La Silla 2.2米望远镜的GROND和VLT/NaCo在爆发前后的近红外波段也观测到了瞬变的位置。在钱德拉误差区域内，我们发现多个对象没有显示出显著的变化。
A highly ionised outflow in the X-ray binary 4U 1624-49 detected with XRISM
ESO（欧洲南方天文台）；SRON Netherlands Institute for Space Research（荷兰空间研究所）；Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA)（日本宇宙航空研究开发机构宇宙科学研究所）；Faculty of Science and Technology, Tokyo University of Science（东京理科大学理工学部）；Department of Physics, Ehime University（爱媛大学理学部物理学科）；Villanova University（维拉诺瓦大学）；NASA/Goddard Space Flight Center（美国国家航空航天局戈达德太空飞行中心）；Center for Research and Exploration in Space Science and Technology, NASA/GSFC (CRESST II)（NASA/GSFC空间科学与技术研究探索中心）；Center for Space Science and Technology, University of Maryland, Baltimore County (UMBC)（马里兰大学巴尔的摩县分校空间科学与技术中心）；Department of Astronomy, University of Michigan（密歇根大学天文学系）
XRISM Observations of Accretion Disk Corona in Cyg X-2
University of Teacher Education Fukuoka（福冈教育大学）；Hiroshima University（广岛大学）；Technion（以色列理工学院）；University of Maryland, Baltimore County (UMBC)（马里兰大学巴尔的摩县分校）；NASA / Goddard Space Flight Center（美国国家航空航天局戈达德太空飞行中心）；University of Michigan（密歇根大学）；SRON Netherlands Institute for Space Research（荷兰空间研究所）；Massachusetts Institute of Technology（麻省理工学院）
EWOCS VII : Unveiling the faint diffuse X-ray emission in Westerlund 1
Universidad Nacional de Río Negro（里奥内格罗国立大学）；European Southern Observatory（欧洲南方天文台）；Space Sciences STAR Institute, University of Liège（列日大学空间科学STAR研究所）；Dublin Institute for Advanced Studies（都柏林高等研究院）；Max-Planck-Institut für Kernphysik（马克斯·普朗克核物理研究所）；Astronomisches Rechen-Institut（天文计算研究所）；Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）；INAF - Osservatorio Astronomico di Palermo G.S. Vaiana（意大利国家天体物理研究所巴勒莫G.S.瓦伊亚天文台）；Dipartimento di Fisica e Chimica E. Segrè, Università degli Studi di Palermo（巴勒莫大学E.塞格雷物理化学系）；Instituto de Astronomı́a y Fı́sica del Espacio (CONICET-UBA)（空间天体物理学研究所（CONICET-UBA））；School of Physics and Astronomy, University of Birmingham（伯明翰大学物理与天文学院）；Center for Astrophysics | Harvard & Smithsonian（哈佛-史密森尼天体物理中心）；Space Telescope Science Institute（太空望远镜科学研究所）；The William H. Miller III Dept. of Physics & Astronomy, Johns Hopkins University（约翰霍普金斯大学威廉H米勒三世物理与天文系）
