A&A 407, 899-904 (2003)
DOI: 10.1051/0004-6361:20030896

The core dominance parameter of extragalactic radio sources

J. H. Fan and J. S. Zhang

Center for Astrophysics, Guangzhou University, Guangzhou 510400, PR China
    e-mail: fjh@gzhu.edu.cn
(Received 20 January 2003 / Accepted 12 June 2003 )

Abstract
In this paper, based on a paper by Liu and Zhang (2002), we have chosen a sample of 542 extragalactic sources (27 BL Lac objects, 300 galaxies (radio galaxies and Seyfert galaxies), and 215 quasars), for which we have calculated the core-dominance parameters and investigated the relation between core-dominance parameter and the core and extended luminosities. The core-dominance parameter of galaxies is smaller than that in quasars, which is smaller than that in BL Lac objects. log for galaxies, log for quasars, and log for BL Lac objects on average respectively. For quasars, there is clear correlation between the core-luminosity and core-dominance parameter and an anti-correlation between the extended luminosity and the core-dominance parameter, which is explained by the beaming effect.

Key words: BL Lacertae objects: general -- quasars: general -- galaxies: Seyfert -- galaxies: jets

Offprint request: Dr. J. H. Fan, fjh@gzhu.edu.cn

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