1306.4177 (Ashok K. Singal et al.)

Incongruity of the unified scheme with a 3CRR-like equatorial strong-source sample    [PDF]

Ashok K. Singal, Raj Laxmi Singh

We examine the consistency of the unified scheme model of the powerful extragalactic radio sources with a 3CRR-like strong-source sample that was selected from the equatorial sky region. It comes out that, unlike in the 3CRR sample, a foreshortening in the observed sizes of quasars, expected from the orientation-based unified scheme model, is not seen in the equatorial sample, at least in different redshift bins up to z~1. Even the quasar fraction in individual redshift bins up to z~1 does not match with that expected from the unified scheme, where radio galaxies and quasars are supposed to belong to a common parent population at all redshifts. This not only casts strong doubts on the unified scheme, but also throws up an intriguing result that in a sample selected from the equatorial sky region, using almost the same criteria as in the 3CRR sample from the northern hemisphere, the relative distribution of radio galaxies and quasars differs qualitatively from the 3CRR sample.

View original: http://arxiv.org/abs/1306.4177