First Observation of a Type II Solar Radio Burst Transitioning Between a Stationary and Drifting State. (arXiv:2003.11101v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Chrysaphi_N/0/1/0/all/0/1">Nicolina Chrysaphi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Reid_H/0/1/0/all/0/1">Hamish A. S. Reid</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kontar_E/0/1/0/all/0/1">Eduard P. Kontar</a>
Standing shocks are believed to be responsible for stationary Type II solar
radio bursts, whereas drifting Type II bursts are excited by moving shocks
often related to coronal mass ejections (CMEs). Observations of either
stationary or drifting Type II bursts are common, but a transition between the
two states has not yet been reported. Here, we present a Type II burst which
shows a clear, continuous transition from a stationary to a drifting state, the
first observation of its kind. Moreover, band splitting is observed in the
stationary parts of the burst, as well as intriguing negative and positive
frequency-drift fine structures within the stationary emissions. The relation
of the radio emissions to an observed jet and a narrow CME were investigated
across multiple wavelengths, and the mechanisms leading to the transitioning
Type II burst were determined. We find that a jet eruption generates a
streamer-puff CME and that the interplay between the CME-driven shock and the
streamer is likely to be responsible for the observed radio emissions.
Standing shocks are believed to be responsible for stationary Type II solar
radio bursts, whereas drifting Type II bursts are excited by moving shocks
often related to coronal mass ejections (CMEs). Observations of either
stationary or drifting Type II bursts are common, but a transition between the
two states has not yet been reported. Here, we present a Type II burst which
shows a clear, continuous transition from a stationary to a drifting state, the
first observation of its kind. Moreover, band splitting is observed in the
stationary parts of the burst, as well as intriguing negative and positive
frequency-drift fine structures within the stationary emissions. The relation
of the radio emissions to an observed jet and a narrow CME were investigated
across multiple wavelengths, and the mechanisms leading to the transitioning
Type II burst were determined. We find that a jet eruption generates a
streamer-puff CME and that the interplay between the CME-driven shock and the
streamer is likely to be responsible for the observed radio emissions.
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