On the Origin of the Hard X-Ray Pulsations during Solar Flares

Zaitsev, V. V. and A. V. Stepanov, On the Origin of the Hard X-Ray Pulsations during Solar Flares, Soviet Astronomy Letters, 8, 132-134 (1982) (ADS)

The cartoon

(click on the image for a larger version)

An early description of the origin of hard X-ray pulsations, discovered by Parks & Winckler (1971) and now known to be commonplace in the form of QPP at 10-30 s periods. Note the behavior of the looptop and its schematic reflection of overpressure; this was long before Yohkoh/SXT and the celebrated Masuda flare drew our attention to this region.

Date: 2019 November 05