• Analysis of enhanced velocity signals observed during solar flares

    • Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/joaa/027/04/0425-0438

    • Keywords

       

      Sun: oscillations; Sun: sunspots; Sun: flares

    • Abstract

       

      Solar flares are known to release a large amount of energy. It is believed that the flares can excite velocity oscillations in active regions. We report here the changes in velocity signals in three active regions which have produced large X-class flares. The enhanced velocity signals appeared during the rise time of the GOES soft X-ray flux. These signals are located close to the vicinity of the hard X-ray source regions as observed with RHESSI. The power maps of the active region show enhancement in the frequency regime 5–6.5 mHz, while there is feeble or no enhancement of these signals in 2–4 mHz frequency band. High energy particles with sufficient momentum seem to be the cause for these observed enhanced velocity signals.

    • Author Affiliations

       

      Brajesh Kumar1 B. Ravindra2

      1. Physical Research Laboratory, Udaipur Solar Observatory, Dewali, Badi Road, P.O. Box 198, Udaipur - 313 001, India
      2. Department of Physics, Montana State University, Bozeman, MT - 59717, USA
    • 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.