Showing papers by "Säm Krucker published in 1994"
Journal Article•
TL;DR: In this paper, the frequency ratio of narrowband millisecond spikes during 17 solar flares has been measured and analyzed, and the cross-correlation of the time profile of harmonic groups peaks at zero lag, demonstrating a tight relation between individual spikes in associated groups.
Abstract: The frequency ratio of narrowband millisecond spikes during 17 solar flares has been measured and analyzed. The observations have been made in the frequency range 0.3-3 GHz with the ETH Zurich spectrometers. The events have been selected from spectrograms for their harmonic structure. Autocorrelation in frequency yields the following major results: (i) The ratio of the harmonic spike groups is not integer, and therefore the term'harmonic'is strictly speaking inappropriate. (ii) The ratios are independent of frequency. (iii) The ratios range from 1.06 to 1.54 with a prominent peak at 1.39±0.01. The cross-correlation of the time profile of harmonic groups peaks at zero lag, demonstrating a tight relation between individual spikes in associated groups
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TL;DR: In this article, events of narrowband spikes have been selected from broadband (survey-type) spectral observations at ETH Zurich covering the past 15 years, where events with at least two bands of spikes well resolved in frequency were taken into consideration.
Abstract: Events of narrowband spikes have been selected from broadband (survey-type) spectral observations at ETH Zurich covering the past 15 years. Only events with at least two bands of spikes well resolved in frequency have been taken into consideration. The total number of selected spike events amounts to 17, whereof three events have three and one has four bands.