This presentation reviews Chandra's major contribution to the understanding of nearby galaxies. After a brief summary on significant advances in characterizing various types of discrete X-ray sources, the presentation focuses on the global hot gas in and around galaxies, especially normal ones like our own. The hot gas is a product of stellar and AGN feedback -- the least understood part in theories of galaxy formation and evolution. Chandra observations have led to the first characterization of the spatial, thermal, chemical, and kinetic properties of the gas in our Galaxy. The gas is concentrated around the Galactic bulge and disk on scales of a few kpc. The column density of chemically-enriched hot gas on larger scales is at least an order magnitude smaller, indicating that it may not account for the bulk of the missing baryon matter predicted for the Galactic halo according to the standard cosmology. Similar results have also been obtained for other nearby galaxies. The X-ray emission from hot gas is well correlated with the star formation rate and stellar mass, indicating that the heating is primarily due to the stellar feedback. However, the observed X-ray luminosity of the gas is typically less than a few percent of the feedback energy. Thus the bulk of the feedback (including injected heavy elements) is likely lost in galaxy-wide outflows. The results are compared with simulations of the feedback to infer its dynamics and interplay with the circum-galactic medium, hence the evolution of galaxies.
The Chandra COSMOS-Legacy survey: Source X-ray spectral properties
本文介绍了钱德拉宇宙遗产巡天目录中1855个河外源的X射线谱分析，这些源在0.5-7 keV波段有30多个净计数。38%的源是光学分类的1型活动星系核（AGN），60%是2型活动星系核，2%是被动的低红移星系。我们研究了活动星系核的光子指数和内禀吸收N（H，z）的分布，并基于源的光学分类：第一类活动星系核的平均光子指数比第二类活动星系核稍陡，而第二类活动星系核的平均内禀吸收比第一类活动星系核高约3倍。我们发现，约15%的1型活动星系核的N（H，z）> 1 E22 cm^（-2），即，根据X射线光谱拟合，这些源中的绝大多数具有L（2- 10 keV）> $1E44 erg/s. The existence of these objects suggests that optical and X-ray obscuration can be caused by different phenomena, the X-ray obscuration being for example caused by dust-free material surrounding the inner part of the nuclei. ~18% of Type 2 AGN have N(H,z)<1E22 cm^(-2), and most of these sources have low X-ra…
The Chandra COSMOS legacy survey: Energy Spectrum of the Cosmic X-ray Background and constraints on undetected populations
使用{ \em钱德拉}观测在2.15度$^{2}$ COSMOS遗产领域，我们提出了一个最准确的测量宇宙X射线背景（CXB）光谱的日期在[0.3-7] keV的能量带。CXB有三个不同的组成部分：来自两个银河系碰撞热等离子体在kT $\sim$ 0.27和0.07千电子伏和河外幂律与光子光谱指数$Γ$ =1.45 $\pm{0.02}$的贡献。河外分量的1 keV标准化为10.91 $\pm{0.16}$ keV cm $^{-2}$ s $^{-1}$ sr $^{-1}$ keV $^{-1}$。去除所有X射线探测源，剩余的未分辨CXB通过幂律最佳拟合，归一化为4.18 $\pm{0.26}$ keV cm $^{-2}$ s $^{-1}$ sr $^{-1}$ keV $^{-1}$，光子谱指数$Γ$ =1.57 $\pm{0.10}$。去除暗星系到i $_{AB}\sim$ 27-28留下了硬光谱，$Γ\sim$为1.25，$\sim$为1.37 keV cm $^{-2}$ s $^{-1}$ sr $^{-1}$ keV $^{-1}$。这意味着观测到的CXB的$\sim$ 91%被分解为探测到的X射线源和未探测到的星系。贡献总CXB的$\sim 8-9\%$的未解析来源显示出比解析来源更难且可能更模糊的边缘证据。CXB的另一个$\sim$ 1可以归因于尚未被发现的恒…
Uncovering New Ionized Winds and Relativistic Hot Outflows in MCG-6-30-15 with \emph{Chandra} HETG and a Bayesian Framework
University of Maryland, College Park（马里兰大学帕克分校）；NASA Goddard Space Flight Center（美国国家航空航天局戈达德太空飞行中心）；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）；Joint Space-Science Institute（联合空间科学研究所）；Department of Astronomy, University of Michigan, Ann Arbor（密歇根大学安娜堡分校天文学系）
Active galactic nuclei-heated dust revealed in "little red dots"
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观测站）；Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM（巴黎萨克雷大学、巴黎西岱大学、法国原子能和替代能源委员会、法国国家科学研究中心、天体物理学和分子成像实验室）；Astronomy Department, University of Massachusetts, Amherst（马萨诸塞大学阿默斯特分校天文学系）；The University of Texas at Austin（德克萨斯大学奥斯汀分校）；University of Bologna, Department of Physics and Astronomy (DIFA)（博洛纳大学物理与天文学系）；Department of Physics, University of California, Santa Barbara（加州大学圣塔芭芭拉分校物理系）
Tracing AGN-Galaxy Co-Evolution with UV Line-Selected Obscured AGN
University of Cape Town（开普敦大学）；Inter-University Institute for Data Intensive Astronomy, Department of Astronomy, University of Cape Town（开普敦大学天文学系跨大学数据密集型天体物理研究所）；INAF - Istituto di Radioastronomia（意大利国家天体物理研究所射电天文台）；Inter-University Institute for Data Intensive Astronomy, Department of Physics and Astronomy, University of the Western Cape（西开普大学物理与天文学系跨大学数据密集型天体物理研究所）；Dipartimento di Fisica e Astronomia “Augusto Righi”, Università degli Studi di Bologna（博洛尼亚大学“奥古斯托·里吉”物理与天文学系）；INAF-OAS, 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体物理学与空间科学观测站）；Instituto de Astrofísíca e Ciências do Espaço, Faculdade de Ciências, Universidade de Lisboa（里斯本大学理学院空间科学与天体物理研究所）；Astronomy and Astrophysics division, Physical Research Laboratory（物理研究实验室天文与天体物理部）；Astrophysics, Department of Physics, University of Oxford（牛津大学物理系天体物理学组）；Institute for Astronomy, University of Edinburgh（爱丁堡大学天体物理研究所）；Department of Physics and Electronics, Rhodes University（罗德岛大学物理与电子学系）；South African Radio Astronomy Observatory（南非射电天文观测台）；Department of Physics and Astronomy, University of the Western Cape（西开普大学物理与天文学系）
Two spectroscopically confirmed galaxy structures at z=0.61 and 0.74 in the CFHTLS Deep~3 field
阿达米等人（2010年）在加拿大-法国-夏威夷望远镜遗产巡天（英语：Canada France Hawaii Telescope Legacy Survey）中，根据光度红移侦测到几个z>0.5的候选星团。我们在这里重点介绍其中两个，位于D3字段：D3-6和D3-43。我们已经获得了光谱与双子座/GMOS和测量红移的23和14个星系的两种结构。这些红移与文献中的数据相结合。还进行了动力学和弱透镜分析，以及X射线钱德拉存档数据的研究。星团D3-6是一个由8个光谱确认成员组成的单一结构，平均红移z=0.607，速度色散为423 km/s。它似乎是一个相对较低质量的星团。D3-43-S3有46个光谱确认的成员，平均红移z=0.739。它可以被分解成两个主要的子结构，具有约600和350公里/秒的速度分散。对D3-43-S3通过弱透镜（仅在~3sigma水平上）而不是在X射线中被检测到的事实的解释可能是这两个子结构刚刚开始沿着视线或多或少地合并。我们还表明，D3-6和D3-43-S3具有相似的全球星系光度函数，恒星质量函数和恒星形成率（SFR）分布。唯一的区别是D3-6缺乏暗淡的早期类型星系，与D3-43-S3相比，缺乏极高恒星质量的星系，以及过多的非常高的SFR星系。这项研究显示了基于光度红移的技术的力量，以检测低到中等质量的结构，即使在z~0.75。
