Radio Observations of the 20 January 2005 X-class Flare

Abstract

We present a multi-frequency and multi-instrument study of the 20 January 2005 event. We focus mainly on the complex radio signatures and their association with the active phenomena taking place: flares, CMEs, particle acceleration, and magnetic restructuring. As a variety of energetic-particle accelerators and sources of radio bursts are present, in the flare -ejecta combination, we investigate their relative importance in the progress of this event. The dynamic spectra of ARTEMIS-IV -Wind/Waves -HiRAS, with 2000 MHz -20 kHz frequency coverage, were used to track the evolution of the event from the low corona to the interplanetary space; these were supplemented with SXR, HXR, and γ -ray recordings. The observations were compared with the expected radio signatures and energetic-particle populations envisaged by the Standard Flare -CME model and the recon-C. Bouratzis · P. Preka-Papadema · A. Hillaris ( ) · X. Moussas 344 C. Bouratzis et al. nection outflow termination shock model. A proper combination of these mechanisms seems to provide an adequate model for the interpretation of the observational data.

The relativistic solar particle event of 2005 January 20: origin of delayed particle acceleration

“…This emission had no counterpart at metric and longer waves (for details see Figs. 1−3 of Bouratzis et al 2010). The low-frequency limit of the radio bursts drifted gradually towards lower frequencies.…”

“…2.3, and the relation with relativistic protons before and during the first release is briefly discussed in Sect. 2.4 with reference to Paper I and to the evolution of the dm-m-wave dynamic spectrum studied by Bouratzis et al (2010). A more detailed analysis of the radio and UV emission accompanying the second relativistic proton release (Sect.…”

High resolution observations with Artemis-IV and the NRH

“…Narrow-band bursts are a general class of fine structures including, but not restricted to, the narrow-band members of the type-III family, spikes, dots and sub-second patches, depending on their shape on the dynamic spectra; part of the same family are the III(U) and III(J) narrow-band bursts reported by Fu et al (2004) and Bouratzis et al (2010). They have been interpreted as signatures of small scale acceleration episodes (e.g., Nindos & Aurass 2007).…”

Μελέτη Λεπτής Υφής Σε Ηλιακές Ραδιοεξάρσεις Τύπου ΙΙ Με Χρήση Ραδιοφασματικών Παρατηρήσεων

“…Στην εικόνα 1.17 βλέπουμε μια σχεδιαστική αναπαράσταση του συνδυαστικού μοντέλου έκλαμψης -στεμματικής εκτόξευσης μάζας, το οποίο περιλαμβάνει την εξέλιξη και αναδιάταξη των μαγνητικών γραμμών (Bouratzis et al, 2010). Στο δεξιό τμήμα της εικόνας φαίνεται η συχνοτική και χρονική αντιστοίχηση της εικόνας με διάφορους τύπους ραδιοεξάρσεων για ένα έντονο φαινόμενο στις 20/1/2005.…”

“…Σε σπάνιες περιπτώσεις φτάνουν μέχρι τη φωτόσφαιρα οπότε έχουμε εκλάμψεις στο λευκό φως. Από την άλλη τα ενεργά ηλεκτρόνια που παγιδεύονται στο βρόχο της έκλαμψης εκπέμπουν Ο ΄Ηλιος Εικόνα 1.17: Σχηματικό διάγραμμα συνδυαστικού μοντέλου έκλαμψης -CME (Bouratzis et al, 2010).…”