标题： 本宇宙中的射电星系：全天 catalog、光度函数和聚类 显示英文标题

标题： Radio galaxies of the local universe: all-sky catalog, luminosity functions, and clustering

摘要： 为了理解黑洞对其环境的反馈作用，或者在当前宇宙时期超高能宇宙射线的加速机制，需要对局部宇宙中的射电星系进行全面的全天普查。 本文介绍了首个满足这一需求的射电发射星系目录。 我们的目录允许选择包含所有低功率射电星系的体积受限子样本，类似于原型低功率射电星系Cen A或M87，这些星系位于数百兆秒差距范围内。 该目录通过匹配NVSS和SUMSS巡天中的射电辐射与2MASS红移巡天（2MRS）中的星系，使用一种在图像级别处理射电源扩展结构的算法构建而成。 样本包含575个在1.4 GHz频率下具有大于213 mJy通量的射电发射星系。 我们目录中超过30%的星系不在现有的大型星系际射电样本中。 我们计算了光学和射电亮度函数以及作为星系亮度函数的射电星系比例。 我们发现射电星系周围的星系密度显著高于相同亮度和形态的非射电星系。 这种增强的聚类表明外部星系属性（如环境或合并历史）与当前宇宙中强大喷流的形成之间存在因果关系。 由于这种增强是相对于相同亮度和哈勃类型的星系观察到的，因此它主要不是由黑洞质量驱动的。 我们的自动化匹配程序被发现以高效率（99%）和纯度（91%）选择射电发射星系，这对未来处理更深、更大的样本至关重要。 显示英文摘要

摘要： To understand the feedback of black holes on their environment or the acceleration of ultra-high energy cosmic rays in the present cosmic epoch, a systematic, all-sky inventory of radio galaxies in the local universe is needed. Here we present the first catalog of radio-emitting galaxies that meets this requirement. Our catalog allows the selection of volume-limited subsamples containing all low-power radio galaxies, similar to the prototypical low-power radio galaxies Cen A or M87, within some hundred Mpc. It is constructed by matching radio emission from the NVSS and SUMSS surveys to galaxies of the 2MASS Redshift Survey (2MRS) using an image-level algorithm that properly treats the extended structure of radio sources. The sample contains 575 radio-emitting galaxies with a flux greater than 213 mJy at 1.4 GHz. Over 30% of the galaxies in our catalog are not contained in existing large-area extra-galactic radio samples. We compute the optical and radio luminosity functions and the fraction of radio galaxies as a function of galaxy luminosity. We find that the galaxy density around radio galaxies is significantly higher than around non-radio galaxies of the same luminosity and morphology. This enhanced clustering suggests a causal relation between external galaxy properties, such as environment or merger history, and the formation of powerful jets in the present universe. Since the enhancement is observed with respect to galaxies of the same luminosity and Hubble type, it is not primarily driven by black hole mass. Our automated matching procedure is found to select radio-emitting galaxies with high efficiency (99%) and purity (91%), which is key for future processing of deeper, larger samples.