Abstract

ONAH, C. I.; UBACHUKWU, A. A.; ODO, F. C.  and  ONUCHUKWU, C. C.. Evolution of extragalactic radio sources and quasar/Galaxy unification. Rev. mex. astron. astrofis [online]. 2018, vol.54, n.1. ISSN 0185-1101.

We use a large sample of radio sources to investigate the effects of evolution, luminosity selection and radio source orientation in explaining the apparent deviation of observed angular size redshift (θ−z) relation of extragalactic radio sources (EGRSs) from the standard model. We have fitted the observed θ − z data with standard cosmological models based on a flat universe (Ω0 = 1). The size evolution of EGRSs has been described as luminosity, temporal and orientation-dependent in the form DP,z,φ ≈ P±q(1 + z)−m sinφ, with q = 0.3, φ = 59◦, m = −0.26 for radio galaxies and q = −0.5, φ = 33◦, m = 3.1 for radio quasars respectively. Critical points of luminosity, log Pcrit = 26.33 WHz−1 and log Dc = 2.51 kpc (316.23 kpc) of the present sample of radio sources were also observed. All the results were found to be consistent with the popular quasar/galaxy unification scheme.

Keywords : galaxies: active; galaxies: evolution; galaxies: general.

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