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Location of Decimetric Pulsations in Solar Flares
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Arnold Benz Submitted: 2011-03-28 08:01
This work investigates the spatial relation between coronal X-ray
sources and coherent radio emissions, both generally thought to be
signatures of particle acceleration. Two limb events were selected
during which the radio emission was well correlated in time with hard
X-rays. The radio emissions were of the type of decimetric pulsations
as determined from the spectrogram observed by Phoenix-2 of ETH
Zurich. The radio positions were measured from observations with the
Nançay Radioheliograph between 236 and 432 MHz and compared to the
position of the coronal X-ray source imaged with RHESSI. The radio
pulsations originated at least 30 - 240 Mm above the coronal hard
X-ray source. The altitude of the radio emission increases generally
with lower frequency. The average positions at different frequencies
are on a line pointing approximately to the coronal hard X-ray source.
Thus, the pulsations cannot be caused by electrons trapped in the
flare loops, but are consistent with emission from a current sheet
above the coronal source.
Authors: Arnold O. Benz, Marina Battaglia and Nicole Vilmer
Projects: RHESSI
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Publication Status: Solar Physics (in press)
Last Modified: 2011-03-28 08:23
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