Title: Energy-dependent modulation in auroral X-ray pulsations
Abstract: In a recent study of auroral electron precipitation, spectral and temporal features of a unique pulsating X-ray event were reported [Brown and Weir, 1967] . The event in question occurred in the magnetic activity after the September 2, 1966, solar cosmic-ray event and was outstanding for its duration and intensity, as shown in Figure 1; in addition, a power spectrum analysis of the intensity variations revealed a 35% decrease in the dominant frequency midway in the event. Analysis of energy spectra of the pulsation excess and enhanced X-ray background showed that both were characterized by photon spectra with average e-folding energies ∼3 kev; this last result is consistent with modulation processes acting on the electron influx rather than spectrally distinct pulsating precipitation embedded within a large-scale background of a different orgin. [Barcus et al. 1966] The present note concerns an analysis of relative changes in the X-ray spectra of these pulsations that reveals regular changes, hardening and softening, as the pulsation peaks develop and decay. Considering optical observations, this gives further evidence for a close association between pulsations of energetic electron precipitation and visual aurora.
Publication Year: 1967
Publication Date: 1967-11-01
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 8
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