首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Examination of the Association between Quasars and Abell Clusters on All Sky
Authors:Xingfen Zhu
Institution:(1) Center for Astrophysics, University of Science and Technology of China, Hefei, Anhui, 230026, China; E-mail address;(2) National Astronomical Observatories, Chinese Academy of Sciences, Beijingg, 100012, China
Abstract:Using the Hewitt-Burbidge QSO Catalogue (1993) and all-sky catalogue of Abell clusters (ACO, 1989) at the region |b| > 40° we analyze the cross correlation function and find anti-correlation between them at angular separations 3° < θ < 10° , which is mainly caused by optical-selected QSOs, rather than radio-selected QSOs. There is no such anti-correlation between QSOs and Abell clusters at smaller separations θ < 3°. Considering that this phenomenon may be caused by different characters of the objects, we further estimate the correlation function with various subsamples. We find that the correlation is independent of the redshift of QSOs, but depends upon the type of Abell clusters: for the D ≤ 4 clusters there is an obvious tendency of overdensity of quasars at 0° < θ < 5°; around the R ≥ 2 Abell clusters there is about an 18.7% deficit of quasars in the region 3° < θ < 7°. K-S Test shows the overdensity or deficit of quasars around different types of clusters cannot be explained by the projection effect of background quasars. We get the enhancement factor of quasar overdensity (for D ≤ 4 clusters) q =1.13, and the extinction magnitude factor of QSO deficiency (for R ≥ 2 clusters) Av= 0.14. This revised version was published online in July 2006 with corrections to the Cover Date.
Keywords:
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号