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Today's colloquium: Tuning in to the Radio Sun

Submitter: Peter Gallagher (Trinity College Dublin)
Description: Cosmic rays and solar energetic particles may be accelerated to relativistic energies by shock waves in astrophysical plasmas. On the Sun, shocks and particle acceleration are often associated with the eruption of magnetized plasmoids, called coronal mass ejections (CMEs). However, the physical relationship between CMEs and shock particle acceleration is not well understood. In this talk, I will show how extreme ultraviolet, radio and white-light images can be used to study CME-induced shocks and associated phenomena such as large-scale coronal waves. I will also show how LOFAR is giving a new insight into our understanding of electron acceleration in the solar corona.

The figure shows a solar radio burst driven by a coronal mass ejection from the Sun. The rapidly varying "herringbones" are thought to result from electrons accelerated by a super-Alfven shock that is driven by a rapidly expanding coronal mass ejection. The dynamic spectra were observed by STEREO/WAVES, the Nancay Decametric Array and TCD's Rosse Observatory at Birr Castle. See Carley et al., Nature Physics, 2013 for further details.
Copyright: Carley et al. / Nature Publishing Group
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