A Catalog of Seyfert, Nuclei, N Systems and Active Galactic Nuclei

多年来，人们一直在收集有关类似类恒星物体(QSO)的信息，例如塞弗特核和N系统。在为最近出版的类星体星表对天体进行分类时，已经发现了许多最近发现的具有相对较小红移的天体，就其连续谱和线谱而言，它们显然与类星体相似。通过X射线技术发现的许多河外来源，通常被称为活动星系核(AGN)，都属于这一类。有时它们显然是正常星系的一部分，而在其他情况下，它们的环境就不那么清晰了。要了解这些现象的一般性质，需要一份这类物体的全面清单。将编制一个类似于以前的类星体星表。要列入星表的天体必须有一个最主要的核特征，并且光谱必须显示出剧烈活动的证据，明显不是由于正常的单星演化，即光谱必须显示出非热连续体的证据，有时是可变的，以及由宽线主导的发射线光谱。原子核通常可以是射电源或X射线源。与类星体的情况一样，已经通过各种技术发现了这些物体：颜色；形态；低色散光谱，包括棱镜物镜技术；以及通过无线电或X射线技术识别后的光学研究。首席调查员估计，该目录将包含500至1000件物品。他计划在1988年出版这本目录。

Information on objects that resemble quasi-stellar objects (QSOs) such as Seyfert nuclei and N systems has been collected for many years. In classifying objects for the recently published QSO catalog, many recently discovered objects with comparatively small redshifts, which clearly resemble QSOs in as far as their continuum and line spectra are concerned, have been found. Many of the extragalactic sources found by X-ray techniques, often called Active Galactic Nuclei (AGN), fall into this category. Sometimes they are clearly parts of normal galaxies, and in other cases their environment is less clear. To look at the general properties of these phenomena, a comprehensive list of such objects is required. A catalog similar to the previous QSO catalog will be prepared. Objects to be included in the catalog must have a nucleus that is the most dominant feature and a spectrum that shows evidence of violent activity clearly not due to the evolution of normal single stars, i.e. the spectrum must show evidence for a nonthermal continuum, sometimes variable, and an emission line spectrum dominated by broad lines. The nucleus may often be a radio source or an X-ray source. As in the case for QSOs, the objects have been found by a variety of techniques: colors; morphology; low dispersion spectroscopy, including the grism-objective prism techniques; and optical studies following identification by radio or X-ray techniques. The Principal Investigator estimates that this catalogue will contain between 500 and 1000 objects. He plans to publish the catalog in 1988.