Abstract
Simultaneous observations of λ5577 O I and X-ray bremsstrahlung reveal that postbreakup quasiperiodic 5- to 15-sec pulsations in these two phenomena are positively correlated. Cross-correlation analysis of the fluctuations shows that λ5577 O I pulses lag corresponding X-ray pulses by ∼0.5–1 sec, a value consistent (within experimental uncertainties) with the effective lifetime of oxygen atoms in the 21S state. The percentage modulation of X rays >25 kev was usually 2–5 times larger than the percentage modulation of auroral light. Estimates of the energy distribution in the primary electron precipitation pulsations indicate that at times as much as 50% of the energy needed to account for the luminosity variations may be carried by electrons with energies greater than 25 kev. It is concluded that pulsating auroras and X rays result from a single process modulating both the low-energy ( 25 kev) primary electron flux. From these observations, gross intensity changes of a slowly varying nature appear to be largely unrelated, in agreement with the majority of previous findings.
Published Version
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