• Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/joaa/033/03/0279-0290

    • Keywords

       

      Galaxies: BL Lacertae objects: general.

    • Abstract

       

      We use the correlation between the core-to-lobe radio luminosity ratio (𝑅) and the linear size (𝐷) of a sample of BL Lacertae objects to investigate the relativistic beaming and radio source orientation paradigm for high peaked and low-peaked BL Lacs (X-ray and radio selected BL Lacs respectively) and to constrain relativistic beaming model for this extreme class of active galactic nuclei. We show that the 𝑅 - 𝐷 distributions of the BL Lac populations contradict blazar orientation sequence, with the X-ray selected BL Lacs (XBLs) being more consistent with the beaming and orientation model. On the premise that Fanaroff-Riley Type I radio galaxies are the unbeamed parent population of these objects, we derive the bulk Lorentz factor of the jets, 𝛾 ∼ 7-20 corresponding to a critical cone angle for optimum boosting, 𝜙c of ∼ 1° - 4°, while on average, these objects are inclined at 5° - 12° to the line-of-sight. The implications of these results for the blazar unification sequence are discussed.

    • Author Affiliations

       

      F. C. Odo1 A. A. Ubachukwu2 A. E. Chukwude2

      1. National Centre for Energy Research and Development, University of Nigeria, Nsukka, Nigeria
      2. Department of Physics & Astronomy, University of Nigeria, Nsukka, Nigeria
    • Dates

       
  • 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.

© 2017-2019 Indian Academy of Sciences, Bengaluru.