The core dominance parameter of extragalactic radio sources*
Center for Astrophysics, Guangzhou University, Guangzhou 510400, PR China e-mail: fjh@gzhu.edu.cn
Corresponding author: Dr. J. H. Fan, fjh@gzhu.edu.cn
Received:
20
January
2003
Accepted:
12
June
2003
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
© ESO, 2003