• C. I. Onah

      Articles written in Journal of Astrophysics and Astronomy

    • On Asymmetries in Powerful Radio Sources and the Quasar/Galaxy Unification

      C. I. Onah A. A. Ubachukwu F. C. Odo

      More Details Abstract Fulltext PDF

      We utilize the distributions of fractional separation difference (𝑥) as asymmetry parameter, linear size (𝐷) and core-to lobe luminosity ratio (𝑅) as orientation indicators, to investigate a consequence of radio source orientation and relativistic beaming effects in a sample of powerful non-symmetric extragalactic radio sources. In this scenario, radio sources viewed at small orientation angles to the line-of-sight are expected to show a high degree of asymmetry in observed radio structures due to relativistic beaming, with foreshortened projected linear sizes. A simple consequence of this is the 𝑥 - 𝐷 anti-correlation. Results show a tight correlation (𝑟 > 0.8) between the total and core radio luminosities and a clear 𝑥 - 𝐷 anti-correlation (𝑟 ∼ -0.5). The observed 𝑥 - 𝐷 anti-correlation is consistent with average orientation angle 𝜙 ≈ 48° and a maximum Lorentz factor 𝛾 ∼ 2 for the sample, with minimum angular separation of 26° between radio galaxies and quasars. However, there is no clear 𝑥 - 𝑅 correlation. While the results are consistent with quasar/galaxy unification via orientation, intrinsic asymmetry also seems to play a major role.

  • Journal of Astrophysics and Astronomy | News

    • Continuous Article Publication

      Posted on January 27, 2016

      Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately. All these have helped shorten the publication time and have improved the visibility of the articles.

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2017-2019 Indian Academy of Sciences, Bengaluru.