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      https://www.ias.ac.in/article/fulltext/joaa/038/02/0024

    • Keywords

       

      Sun; corona; magnetic field; flares; radio bursts; polarization

    • Abstract

       

      We recently investigated some of the hitherto unreported observational characteristics of the low frequency (85–35 MHz) type III–V bursts from the Sun using radio spectropolarimeter observations. The quantitative estimates of the velocities of the electron streams associated with the above two types of bursts indicate that they are in the range ${\gtrsim }0.13c–0.02c$ for the type V bursts, and nearly constant (${\approx }0.4c$) for the type III bursts. We also find that the degree of circular polarization of the type V bursts vary gradually with frequency/heliocentric distance as compared to the relatively steeper variation exhibited by the preceding type III bursts. These imply that the longer duration of the type V bursts at any given frequency (as compared to the preceding type III bursts) which is its defining feature, is due to the combined effect of the lower velocities of the electron streams that generate type V bursts, spread in the velocity spectrum, and the curvature of the magnetic field lines along which they travel.

    • Author Affiliations

       

      P. Kishore1 C. Kathiravan2 R. Ramesh2 E. Ebenezer3

      1. National Institute of Technology, Surathkal 575 025, India.
      2. Indian Institute of Astrophysics, Bangalore 560 034, India.
      3. Indian Institute of Astrophysics, Kodaikanal 624 103, India.
    • Dates

       
  • Journal of Astrophysics and Astronomy | News

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