Interstellar dust permeates our Galaxy and plays an important role in many physical processes in the diffuse and dense regions of the interstellar medium. High-resolution X-ray spectroscopy, coupled with modelling based on laboratory dust measurements, provides a unique probe to investigate the interstellar dust properties along our line of sight towards Galactic X-ray sources. Here, we focus on the oxygen content of the interstellar medium through its absorption features in the X-ray spectra. To model the dust features, we perform a laboratory experiment using the electron microscope facility located at the University of Cadiz in Spain, where we acquire new laboratory data in the oxygen K-edge. We study 18 dust samples of silicates and oxides with different chemical compositions. The laboratory measurements are adopted for our astronomical data analysis. We carry out a case study on the X-ray spectrum of the bright low-mass X-ray binary Cygnus X-2, observed by XMM-Newton. We determine different temperature phases of the ISM, and parameterize oxygen in both gas (neutral and ionised) and dust form. We find Solar abundances of oxygen along the line of sight towards the source. Due to both the relatively low depletion of oxygen into dust form and the shape of the oxygen cross section profiles, it is challenging to determine the precise chemistry of interstellar dust. However, silicates provide an acceptable fit. Finally, we discuss the systematic discrepancies in the atomic (gaseous phase) data of the oxygen edge spectral region using different X-ray atomic databases, and also consider future prospects for studying the ISM with the Arcus concept mission.
Highly Ionized Fe-K Absorption Line from Cygnus X-1 in the High/Soft State Observed with Suzaku
2011年10月5日，在高/软状态期间，我们在朱雀观测的天鹅座黑洞X-1的高级会合附近观测到了一条瞬态类He Fe K α吸收线，这使我们能够首次绘制出从幕式吸积现象或下降开始和结束的完整演化。我们在事件中的X射线光谱模型，并跟踪其演变。吸收线在观测的前半部分相当弱，但在~10 ks时立即加深，之后减弱。等效宽度的总体变化是~3的因子，在~0.08的轨道相位处达到峰值。这是为黑洞提供能量的伴星风是星云的证据。通过分析与Voigt配置文件的线，它被发现是符合轻微红移的Fe XXV过渡，或可能是几个物种的混合物比Fe XXV少电离。这些数据可以用一个距离约为10^（10-12）cm、密度约为10^（（-13）-（-11））g cm^-3的团块来解释，该团块吸积到黑洞上，并/或通过视线到达黑洞，导致观测到的电离度瞬间下降和/或吸积物质密度增加。通过未来的X射线量热计任务（如ASTRO-H和AXSIO）继续监测个别事件，将使我们能够详细绘制出吸积环境及其在各种吸积状态之间的变化。
XRISM High-Resolution X-ray Spectroscopy of Cygnus X-1 -- Orbital and Short-Term Variability of Iron Absorption
Tokyo University of Science（东京科学大学）；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）；California Institute of Technology（加州理工学院）；University of Michigan（密歇根大学）；Massachusetts Institute of Technology（麻省理工学院）；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）
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）
A relativistically broadened O VIII Lyalpha line in the ultra-compact X-ray binary 4U 0614+091
超紧凑的X射线双星由一颗中子星或黑洞组成，它从一颗白矮星-施主星上吸积了物质。超紧凑的性质表现在轨道周期非常短，不到1小时。在4U 0614+091的情况下，来自CO或ONE白矮星的富氧物质流向中子星。这个富含氧的圆盘可以反射中子星发出的X射线，给出一个特征性的发射光谱。本文分析了XMM-Newton卫星获得的4U 0614+091的高分辨率RGS谱和宽谱EPIC谱。我们检测到一个广泛的发射功能，在这两个仪器，这不能解释不寻常的丰度的氧和氖的视线，在文献中提出的。我们解释这一特征为O VIII Lyalpha发射所造成的反射的X射线的高度电离的氧，在强引力场接近中子星。
XRISM detection of the 6.4 keV Fe K$α$ line in the radio galaxy Cygnus A
Waterloo Centre for Astrophysics, Department of Physics and Astronomy（滑铁卢天体物理中心，物理与天文系）；Space Research Organisation Netherlands（荷兰空间研究所）；Center for Astrophysical Sciences, William H. Miller III Department of Physics and Astronomy, Johns Hopkins University（约翰斯·霍普金斯大学威廉·H·米勒三世天体物理学科学中心，物理与天文系）；School of Earth and Space Exploration, Arizona State University（亚利桑那州立大学地球与太空探索学院）；Leiden Observatory, Leiden University（莱顿大学莱顿天文台）；RIKEN High Energy Astrophysics Laboratory（理化学研究所高能天体物理实验室）；Department of Physics, Tokyo University of Science（东京科学大学物理系）；Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo（东京大学宇宙线物质宇宙学卡弗里研究所）
利用XRISM Resolve的高光谱分辨率，分析了天鹅座A核心的170 ks观测数据，通过6.4 keV Fe Kα线复合体揭示了内吸积区结构，发现两个开普勒展宽成分，分别来自宽线区和环状体，并探测到可能的Fe XVII发射线和Fe K边的红移。
Investigating interstellar dust along the line of sight of GX 13+1 using different dust size distributions
Scuola Universitaria Superiore IUSS Pavia（帕维亚高等大学学院）；Department of Physics, University of Trento（特伦托大学物理系）；Istituto Nazionale di Astrofisica, Istituto di Astrofisica Spaziale e Fisica Cosmica di Milano（国家天体物理学研究所，米兰空间天体物理学与宇宙物理学研究所）；SRON Space Research Organisation Netherlands（荷兰空间研究组织）；European Space Agency (ESA), European Research and Technology Centre (ESTEC)（欧洲航天局（ESA），欧洲研究与技术中心（ESTEC））；Anton Pannekoek Institute for Astronomy, University of Amsterdam（阿姆斯特丹大学安东·潘内库克天文学研究所）；DAMTP, Centre for Mathematical Sciences, University of Cambridge（剑桥大学数学科学中心应用数学与理论物理系）；Kavli Institute for Cosmology Cambridge（剑桥卡弗里宇宙学研究所）
