On the relativistic beaming and orientation effects in core-dominated quasars |
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Authors: | A A Ubachukwu A E Chukwude |
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Institution: | (1) Department of Physics and Astronomy, University of Nigeria Nsukka, Nigeria;(2) Regular Associate of the Abdus Salam ICTP, Trieste, Italy |
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Abstract: | In this paper, we investigate the relativistic beaming effects in a well-defined sample of core-dominated quasars using the
correlation between the relative prominence of the core with respect to the extended emission (defined as the ratio of core-to
lobe-flux density measured in the rest frame of the source) and the projected linear size as an indicator of relativistic
beaming and source orientation. Based on the orientation-dependent relativistic beaming and unification paradigm for high
luminosity sources in which the Fanaroff-Riley class-II radio galaxies form the unbeamed parent population of both the lobe-
and core-dominated quasars which are expected to lie at successively smaller angles to the line of sight, we find that the
flows in the cores of these core-dominated quasars are highly relativistic, with optimum bulk Lorentz factor,γ
opt∼ 6–16, and also highly anisotropic, with an average viewing angle, ∼ 9°–16°. Furthermore, the largest boosting occurs within
a critical cone angle of ≈ 4°–10°. |
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Keywords: | Galaxies active jets quasars general |
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