Coronal Magnetic Field Lines and Electrons Associated with Type III–V Radio Bursts in a Solar Flare

Article

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.

Keywords

Sun corona magnetic field flares radio bursts polarization 

Notes

Acknowledgements

The authors would like to thank the Gauribidanur Observatory staff for their help in observations, and maintenance of the antenna and receiver systems. They also thank H. A. Srimathi and Anitha Ravishankar (formerly with Christ University, Bangalore) for their contributions to the present work during their student internship in the Gauribidanur Observatory.

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Copyright information

© Indian Academy of Sciences 2017

Authors and Affiliations

  • P. Kishore
    • 1
  • C. Kathiravan
    • 2
  • R. Ramesh
    • 2
  • E. Ebenezer
    • 3
  1. 1.National Institute of TechnologySurathkalIndia
  2. 2.Indian Institute of AstrophysicsBangaloreIndia
  3. 3.Indian Institute of AstrophysicsKodaikanalIndia

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