Title: Time delays in quasi-periodic pulsations observed during the x2.2 solar flare on 2011 february 15
Authors: Dolla, L ×
Marque, C
Seaton, D. B
Van Doorsselaere, Tom
Dominique, M
Berghmans, David
Cabanas, C
De Groof, A
Schmutz, W
Verdini, A
West, M. J
Zender, J
Zhukov, A. N #
Issue Date: 27-Mar-2012
Publisher: I O P Publishing Ltd.
Series Title: The Astrophysical Journal. Letters vol:749 issue:1 pages:-
Article number: L16
Abstract: We report observations of quasi-periodic pulsations (QPPs) during the X2.2 flare of 2011 February 15, observed simultaneously in several wavebands. We focus on fluctuations on timescale 1-30 s and find different time lags between different wavebands. During the impulsive phase, the Reuven Ramaty High Energy Solar Spectroscopic Imager channels in the range 25-100 keV lead all the other channels. They are followed by the Nobeyama RadioPolarimeters at 9 and 17 GHz and the extreme-ultraviolet (EUV) channels of the Euv SpectroPhotometer (ESP) on board the Solar Dynamic Observatory. The zirconium and aluminum filter channels of the Large Yield Radiometer on board the Project for On-Board Autonomy satellite and the soft X-ray (SXR) channel of ESP follow. The largest lags occur in observations from the Geostationary Operational Environmental Satellite, where the channel at 1-8 angstrom leads the 0.5-4 angstrom channel by several seconds. The time lags between the first and last channels is up to approximate to 9 s. We identified at least two distinct time intervals during the flare impulsive phase, during which the QPPs were associated with two different sources in the Nobeyama RadioHeliograph at 17 GHz. The radio as well as the hard X-ray channels showed different lags during these two intervals. To our knowledge, this is the first time that time lags are reported between EUV and SXR fluctuations on these timescales. We discuss possible emission mechanisms and interpretations, including flare electron trapping.
ISSN: 2041-8205
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Plasma-astrophysics Section
× corresponding author
# (joint) last author

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