Structure and Movement of Solar Noise Storms

Abstract

RELATIVE positions of type I sources and the associated continuum have been measured from observations of several noise storms at 169 MHz. During a given storm the positions of the type I events in the corona are all very nearly the same, and therefore the source of excitation of these events is very localized. For a given storm, more than one source of excitation may exist. The measurements also suggest certain systematic motions of the source of excitation. This letter is based on a study of ten noise storms. The observing period for each storm varied between 20 min and 1 h 30 min, and the continuum flux of the noise storms was between 1 and 5 × 10⁻²² W m⁻² Hz⁻¹. The examples considered correspond in general to only one centre of continuum emission visible on the interferometer during the entire observation.