• Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/joaa/032/01-02/0117-0120

    • Keywords

       

      Galaxies: active; galaxies: quasars: individual: 3C 273; X-rays: galaxies.

    • Abstract

       

      We have developed analysis tools to search for quasi periodic oscillations in light curves from active galactic nuclei, using the following time series techniques: Wavelets, periodogram, Lomb–Scargle periodogram, structure function and multi-harmonic analysis of variance.

      The analysis tools incorporate different noise models with significant levels for all the techniques that is an improvement over the previous work. By looking for consistently high significance, we make the detection of periodicities more robust. We apply this tool to a previously reported QPO (Espaillat et al. 2008) in the X-ray light curve of 3C 273 with a periodicity of ∼ 3300 s and find that the significance is only 74% in the wavelet and fails to show up above 95% significance in the periodogram and multi-harmonic analysis of variance.

    • Author Affiliations

       

      P. Mohan1 A. Mangalam1 Hum Chand2 Alok C. Gupta2

      1. Indian Institute of Astrophysics, Sarjapur Road, Koramangala, Bangalore 560 034, India.
      2. Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital 263 129, India.
    • 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.

    • 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.