Abstract

One of the mainstreams in modern X-ray astronomy is research into extragalactic X-ray sources on the basis of the data acquired at the X-ray Multi-Mirror Newton (XMM-Newton) space observatory. According to observations, X-rays coming from galaxies are mainly radiated from their central regions, i.e., active galactic nuclei and groups of X-ray sources in the galactic disks. In this paper, we consider the cross-correlation between the 4XMM-DR9 catalog and the Hyper-Linked Extragalactic Databases and Archives (HyperLeda) of galaxies. The 4XMM-DR9 catalog is a large, up-to-date catalog of observations, which contains 550 124 unique sources and covers 2.85% of the sky, while the HyperLeda database comprises 1.5 million galaxies. Our analysis resulted in a sample of more than 5000 X-ray galaxies, most of which are active galactic nuclei of low luminosity. From this sample, we selected galaxies whose the X-ray flux exceeds F = 10^–20 J/cm²s. The sources of this kind are of particular interest since it is easier to construct an informative spectrum for them. The identified and classified catalog of 1172 manually verified galaxies—the X-ray galaxy catalog named Xgal—was created. In the Xgal catalog, most galaxies have an active X-ray nucleus; Seyfert galaxies predominate among them at short distances, while quasars are prevalent at large distances. We revealed 169 galaxies that exhibit extended nuclei with a visible surface brightness distribution and 173 galaxies with more than one X-ray source. Based on the Xgal catalog, we created a catalog of elongated X-ray galaxies (the optical angular sizes of which are a > 60″) that have X-ray sources outside the nucleus. Both catalogs are freely accessible. The Xgal catalog may serve to construct the spectra of objects of a certain class in different ranges, to develop or improve the theory of their emission, and to survey bright and extended quasars. Moreover, the entire cross-sample may be used to study active galactic nuclei with low luminosity and a large-scale structure of the universe in the X-ray range.

中文翻译：

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X 射线星系的 Xgal 目录

摘要

现代 X 射线天文学的主流之一是基于 X 射线多镜牛顿(XMM-牛顿) 太空天文台。根据观测，来自星系的X射线主要从其中心区域辐射，即活动星系核和星系盘中的X射线源群。在本文中，我们考虑了 4XMM-DR9 目录与星系超链接的河外数据库和档案 (HyperLeda) 之间的互相关。4XMM-DR9 目录是一个大型的最新观测目录，其中包含 550 124 个独特的来源，覆盖了 2.85% 的天空，而 HyperLeda 数据库包含 150 万个星系。我们的分析产生了超过 5000 个 X 射线星系的样本，其中大部分是低光度的活动星系核。从这个样本中，我们选择了 X 射线通量超过F = 10 ^–20 J/cm ^{2 的}星系s。这种来源特别令人感兴趣，因为为它们构建信息范围更容易。创建了 1172 个人工验证星系的识别和分类目录——名为 Xgal 的 X 射线星系目录。在 Xgal 目录中，大多数星系都有一个活跃的 X 射线核；赛弗特星系在它们中的短距离占主导地位，而类星体在远距离占主导地位。我们揭示了 169 个具有可见表面亮度分布的扩展核的星系和 173 个具有不止一个 X 射线源的星系。基于所述Xgal的目录，我们创建了一个目录细长透视星系（其中光角尺寸是一个> 60") 在核外有 X 射线源。这两个目录都可以免费访问。Xgal 目录可用于构建不同范围内某一类天体的光谱，发展或改进其发射理论，以及调查明亮和扩展的类星体。此外，整个交叉样本可用于研究X射线范围内具有低光度和大尺度宇宙结构的活动星系核。