期刊
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
卷 149, 期 1, 页码 29-51出版社
IOP PUBLISHING LTD
DOI: 10.1086/378229
关键词
BL Lacertae objects : general; catalogs; galaxies : clusters : general; surveys; X-rays : general; X-rays : stars
The X-ray data around the North Ecliptic Pole (NEP) of the ROSAT All Sky Survey have been used to construct a contiguous area survey consisting of a sample of 445 individual X-ray sources above a flux of similar to2 x 10(-14) ergs cm(-2) s(-1) in the 0.5-2.0 keV energy band. The NEP survey is centered at alpha(2000) = 18(h)00(m), delta(2000) = +66degrees33' and covers a region of 80.7 deg(2) at a moderate Galactic latitude of b = 29.degrees8. Hence, the NEP survey is as deep and covers a comparable solid angle to the ROSAT serendipitous surveys but is also contiguous. We have identified 99.6% of the sources and determined redshifts for the extragalactic objects. In this paper we present the optical identifications of the NEP catalog of X-ray sources including basic X-ray data and properties of the sources. We also describe with some detail the optical identification procedure. The classification of the optical counterparts to the NEP sources is very similar to that of previous surveys, in particular the Einstein Extended Medium Sensitivity Survey (EMSS). The main constituents of the catalog are active galactic nuclei (AGNs) (similar to49%), either type 1 or type 2 according to the broadness of their permitted emission lines. Stellar counterparts are the second most common identification class (similar to34%). Clusters and groups of galaxies comprise 14%, and BL Lacertae objects 2%. One non-AGN galaxy and one planetary nebula have also been found. The NEP catalog of X-ray sources is a homogeneous sample of astronomical objects featuring complete optical identification.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据