• On the unified scheme for high-excitation galaxies and quasars in 3CRR sample

• # Fulltext

https://www.ias.ac.in/article/fulltext/joaa/040/01/0006

• # Keywords

Galaxies: active; galaxies: quasars; general.

• # Abstract

In this paper, we use the distributions of luminosity ($P$) and radio size ($D$) to re-examine the consistency of the unified scheme of high-excitation radio galaxies and quasars in the recently updated 3CRR sample. Based on a standard cosmology, we derive theoretically and show from observed data, the luminosity limit above which the 3CRR objects are well-sampled. We find, on average, a quasar fraction $\sim$0.44 and galaxy-to-quasar size ratio $\approx$2. Assuming a relativistic outflow of jet materials, we find a mean angle to the line of sight in the range 35$^{\circ} \leq \phi \leq 44^{\circ}$ for the quasars. On supposition of luminosity and orientation-dependent linear size evolution, expressed in a general functional form $D_{\rm (P,z,\phi)} \approx P^{\pm q}(1+z)^{−w} \sin \phi$, we show that above the flux detection threshold of the 3CRR sample, high-excitation galaxies and quasars undergo similar evolutionwith $q = −0.5$; $w = −0.27$ and luminosity independent evolution parameter $x = 2.27$, when orientation effect is accounted for. The results are consistent with orientation-based unified scheme for radio galaxies and quasars.

• # Author Affiliations

1. Department of Physics and Astronomy, University of Nigeria, Nsukka, Nigeria.

• # Journal of Astrophysics and Astronomy

Current Issue
Volume 40 | Issue 5
October 2019

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