Radio wave propagation in the solar corona: high-time-resolution with LOFAR.
Abstract
Using the Low Frequency Array (LOFAR), we analyse the source sizes and locations of the fine frequency structuresin a solar radio burst. The high time resolution allows us to determine the location and the size of the radioemission source, and its evolution with time, following the radio emission propagation through the solar corona.It is found that intrinsically very small radio sources have an apparent size that is a thousand times larger thanthe actual region where the radio waves originate [1]. The observations suggest that it is radio wave propagationeffects, rather than the intrinsic properties of the emission source, that determine the observed spatial characteristicsof the plasma emission radio bursts. In addition, the observations provide a new opportunity for diagnostics ofsmall-scale plasma fluctuations by imaging the radio source halos as the radio waves move in the solar corona.[1] Kontar et al.: Imaging Spectroscopy of Solar Radio Burst Fine Structures, Nature Communications 8, Articlenumber: 1515 (2017) DOI: 10.1038/s41467-017-01307-8
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E.341B