The 17 January 2005 Complex Solar Radio Event Associated with Interacting Fast Coronal Mass Ejections

• Published in: Solar physics Vol. 273; no. 2; pp. 493 - 509
• Main Authors: Hillaris, A., Malandraki, O., Klein, K.-L., Preka-Papadema, P., Moussas, X., Bouratzis, C., Mitsakou, E., Tsitsipis, P., Kontogeorgos, A.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-11-2011; Springer Nature B.V; Springer Verlag
• Subjects: Astrophysics; Astrophysics and Astroparticles; Atmospheric Sciences; Corona; Energy storage; Energy Storage and Release - Models Meet Radio Observations; Physics; Physics and Astronomy; Propagation; Radio astronomy; Shock waves; Solar activity; Solar physics; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Radio bursts, meter-wavelengths and longer (m, dkm, hm, km); Coronal mass ejections; Energetic particles, electrons; Energetic particles, acceleration; Energetic particles, propagation
• ISSN: 0038-0938; 1573-093X
• DOI: 10.1007/s11207-011-9872-9

On 17 January 2005 two fast coronal mass ejections were recorded in close succession during two distinct episodes of a 3B/X3.8 flare. Both were accompanied by metre-to-kilometre type-III groups tracing energetic electrons that escape into the interplanetary space and by decametre-to-hectometre type-II bursts attributed to CME-driven shock waves. A peculiar type-III burst group was observed below 600 kHz 1.5 hours after the second type-III group. It occurred without any simultaneous activity at higher frequencies, around the time when the two CMEs were expected to interact. We associate this emission with the interaction of the CMEs at heliocentric distances of about 25 
R
⊙
. Near-relativistic electrons observed by the EPAM experiment onboard ACE near 1 AU revealed successive particle releases that can be associated with the two flare/CME events and the low-frequency type-III burst at the time of CME interaction. We compare the pros and cons of shock acceleration and acceleration in the course of magnetic reconnection for the escaping electron beams revealed by the type-III bursts and for the electrons measured
in situ
.