Environmental effects on structural asymmetry in extragalactic radio sources and quasar/galaxy unification
Department of Physics, Federal University of Technology, Owerri, Nigeria
2 Department of Physics and Astronomy, University of Nigeria, Nsukka, Nigeria
Accepted: 21 April 2021
Published online: 25 May 2021
We use the anti-correlation between arm-length ratio (Q) and flux density ratio (F) as asymmetry parameters to investigate the effects of environment on observed structural asymmetries in extragalactic radio sources. In a density variation model (DVM) the Q–F anti-correlation can be understood in the framework of varying beam power due to varying density profile of the environment through which the jets propagate. We find that the variations of Q and F are statistically different for radio galaxies and quasars, with radio galaxies being more consistent with DVM asymmetries than quasars. Linear regression analyses yield significant Q–F anti-correlation which dominates at an upper envelope data, with correlation coefficients r ~ − 0.9 and − 0.7, respectively, for radio galaxies and quasars. All these results are not only consistent with quasar/galaxy unification scheme but suggest that environmental effects contribute significantly to the observed structural asymmetries in extragalactic radio sources.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021