TY - JOUR
TI - Detection of spike-like structures near the front of type-II bursts
AU - Armatas, S.
AU - Bouratzis, C.
AU - Hillaris, A.
AU - Alissandrakis, C.E.
AU - Preka-Papadema, P.
AU - Moussas, X.
AU - Mitsakou, E.
AU - Tsitsipis, P.
AU - Kontogeorgos, A.
JO - Chinese Astronomy and Astrophysics
PY - 2019
VL - 624
TODO - null
SP - null
PB - EDP Sciences
SN - 0275-1062
TODO - 10.1051/0004-6361/201834982
TODO - Bandwidth;  Radio astronomy, Dynamic spectrum;  High-time resolution;  Pulsating structure;  Relative bandwidth;  Solar radio bursts;  Sun : corona;  Sun: activity;  Sun: radio radiation, Spectrographs
TODO - Aims. We examine high time resolution dynamic spectra for fine structures in type II solar radio bursts Methods. We used data obtained with the acousto-optic spectrograph receiver of the Artemis-JLS (ARTEMIS-IV) solar radio spectrograph in the 450-270 MHz range at 10 ms cadence and identified more than 600 short, narrowband features. Their characteristics, such as instantaneous relative bandwidth and total duration were measured and compared with those of spikes embedded in type IV emissions. Results. Type II associated spikes occur mostly in chains inside or close to the slowly drifting type II emission. These spikes coexist with herringbone and pulsating structures. Their average duration is 96 ms and their average relative bandwidth 1.7%. These properties are not different from those of type IV embedded spikes. It is therefore possible that they are signatures of small-scale reconnection along the type II shock front. © ESO 2019.
ER -