Cheung identified a sample of 100 candidate X-shaped radio galaxies using the NRAO FIRST survey; these are small-axial-ratio extended radio sources with off-axis emission. Here we present radio images of 52 of these sources that have been made from archival Very Large Array data with resolution of about 1 arcsec. Fifty-one of the 52 were observed at 1.4 GHz, seven were observed at 1.4 GHz and 5 GHz, and one was observed only at 5 GHz. We also present overlays of the SDSS red images for 48 of the sources, and DSS II overlays for the remainder. Optical counterparts have been identified for most sources, but there remain a few empty fields. Our higher resolution VLA images along with FIRST survey images of the sources in the sample reveal that extended extragalactic radio sources with small axial ratios are largely (60%) cases of double radio sources with twin lobes that have off-axis extensions, usually with inversion-symmetric structure. The available radio images indicate that at most 20% sources might be genuine X-shaped radio sources that could have formed by a restarting of beams in a new direction following an interruption and axis flip. The remaining 20% are in neither of these categories. The implications of this result for the gravitational wave background are discussed in Roberts, Saripalli, and Subrahmanyan.
What Are "X-Shaped" Radio Sources Telling Us? I. Very Large Array Imaging of a Large Sample of Low Axial Ratio Radio Sources
我们提出了历史的VLA和Jansky甚大阵多频多阵无线电连续成像的一个独特的样本的100个无线电源，已选定的基础上，低轴比。这些观测使我们有机会研究与同步加速器等离子体，是显着偏离主无线电轴的射电源，因此打开了一个窗口，调查负责沉积等离子体在离轴区域的物理机制。这些图像将在本系列的后续论文中详细讨论（Saripalli & Roberts 2017; Roberts & Saripalli 2017）。
J023721.13$-$010528.5: A Giant $S$-shaped Radio Galaxy Showing Four Episodes of Jet Activity
Indian Institute of Science Education and Research（印度科学教育研究所）；National Centre for Radio Astrophysics - Tata Institute of Fundamental Research（塔塔基础研究院国家射电天文中心）
CHANG-ES. XXXVIII. A Thin Radio Halo Shaped by Slow Cosmic-Ray Transport in the Quiescent Galaxy NGC 4565
University of Science and Technology of China（中国科学技术大学）；Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）；Hamburger Sternwarte, Universität Hamburg（汉堡天文台，汉堡大学）；Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）；Queen’s University（女王大学）；Department of Astronomy, University of Massachusetts, Amherst（马萨诸塞大学阿默斯特分校天文学系）；Ruhr University Bochum（鲁尔大学波鸿分校）
Catalogue with visual morphological classification of 32,616 radio galaxies with optical hosts
我们提出了与光学Galerkin和具有未分辨或扩展形态I（ROGUE I）相关的射电源目录。它是由斯隆数字巡天数据发布7（SDSS DR 7）的交叉匹配星系以及来自20厘米射电天空第一图像（FIRST）和国家射电天文台VLA巡天（NVSS）目录的射电源产生的。我们创建了最大的手工目录的视觉分类的无线电对象和与他们相关联的光学宿主星系，包含32，616个星系的第一个核心内的光学位置3弧秒。所有列出的对象具有良好的质量SDSS DR 7光谱的信噪比$>$ 10和光谱红移高达$z=0.6$。通过目视检查覆盖在DSS图像上的FIRST和NVSS等高线图进行射电形态分类，而光学形态分类基于SDSS DR 7的120弧秒快照图像。ROGUE I中的大多数射电星系，即$\sim$ 93%，是无法分辨的（紧凑或细长），而其余的则表现出扩展的形态，如Fanaroff-Riley（FR）I型，II型，混合型，广角尾，窄角尾，头-尾源，以及具有间歇或重新定向喷流活动的源，即双-双，X形和Z形。大多数FR II的射电光度都很低，与FR I的光度相当。此外，由于对所有射电图和光学图像的目视检查，我们能够发现或重新分类一些射电天体，如巨型，双双，X形和Z形射电星系。所提出的样本可以作为一个数据库的培训自动识别和分类的光学和射电星系的方法。
A VLA search for compact radio sources in the explosive molecular outflows DR 21 and G5.89
Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México（墨西哥国立自治大学无线电天文学与天体物理研究所）；Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）
The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars I. Identifying and Characterizing the Protostellar Content of the OMC2-FIR4 and OMC2-FIR3 Regions
Radio sources associated with Optical Galaxies and having Unresolved or Extended morphologies (ROGUE). I. A catalog of SDSS galaxies with FIRST core identifications
我们提出了与光学星系团和具有未分辨或扩展形态I（ROGUE~I）的射电源目录，包括32，616个光谱选择的星系。这是此类最大的手工星表，通过交叉匹配斯隆数字巡天（SDSS）数据发布7的星系和来自20厘米射电天空第一图像（FIRST）巡天和NRAO VLA巡天\textit{without imposing a limit to the radio flux densities}的射电源获得。该星表提供了星系射电和光学形态的\textit{visual}分类，在光学位置的3 \arcsec \内呈现第一核心。通过检查在源距离处等于1 Mpc的线性尺寸的无线电-光学叠加来执行无线电形态分类，而来自SDSS数据库的120 \arcsec \图像快照用于光学分类。我们的搜索结果是：（i）单成分的未分辨和拉长的射电源构成ROGUE I星表中的主要类别（$\sim$ 90%）和$\sim$ 8%显示{ \it扩展}形态，（ii）269，730和115 Fanaroff-Riley（FR）I型，II型和混合星系的样本，分别，（iii）我们报告了55个新发现的巨/可能巨射电源，16个双双射电源，9个X形射电源，25个Z形射电源;（iv）在光学锋上，大多数星系都有椭圆形的形态（$\sim$ 62%），而螺旋形形成第二大类（$\sim$ 17%），其次是扭曲（$\sim$ 12%）和晶状体（$\sim…
