Spatial analysis of solar type III events associated with narrow band spikes at metric wavelengths

• Main Authors: Paesold, G, Benz, A. O, Klein, K. -L, Vilmer, N
• Format: Journal Article
• Language: English
• Published: 29-03-2001
• Subjects: Physics - Astrophysics of Galaxies; Physics - Cosmology and Nongalactic Astrophysics; Physics - Earth and Planetary Astrophysics; Physics - High Energy Astrophysical Phenomena; Physics - Instrumentation and Methods for Astrophysics; Physics - Solar and Stellar Astrophysics
• DOI: 10.48550/arxiv.astro-ph/0103491

The spatial association of narrow band metric radio spikes with type III
bursts is analyzed. The analysis addresses the question of a possible causal
relation between the spike emission and the acceleration of the energetic
electrons causing the type III burst. The spikes are identified by the
Phoenix-2 spectrometer (ETH Zurich) from survey solar observations in the
frequency range from 220 MHz to 530 MHz. Simultaneous spatial information was
provided by the Nancay Radioheliograph (NRH) at several frequencies. Five
events were selected showing spikes at one or two and type III bursts at two or
more Nancay frequencies. The 3-dimensional geometry of the single events has
been reconstructed by applying different coronal density models. As a working
hypothesis it is assumed that emission at the plasma frequency or its harmonic
is the responsible radiation process for the spikes as well as for the type III
bursts. It has been found that the spike source location is consistent with the
backward extrapolation of the trajectory of the type III bursts, tracing a
magnetic field line. In one of the analyzed events, type III bursts with two
different trajectories originating from the same spike source could be
identified. These findings support the hypothesis that narrow band metric
spikes are closely related to the acceleration region.