Homology of X-ray bursts

Abstract

The present paper demonstrates on the basis of 2 series of events that one can extend the homology so far known for optical and radio flares also to the hard and soft X-ray bursts. The studied homologous X-ray flares occurred in the same active region and their time-intensity profiles were very similar. It has been found that the detected homologous X-ray bursts are associated with radio bursts that also are homologous. The time profile of centimeter radio bursts frequently is repeated in detail when compared with the time profile of X-ray bursts as one can see in Figure 1. This very close correspondence suggests that the centimeter radio bursts and X-ray bursts are generated simultaneously during flares, probably in the same region (Sengupta, 1968). Arnoldy et al. (1968) have found a detailed correlation between the time-intensity profiles of hard X-ray bursts and 3 or 10 cm radio bursts. This close correlation between the hard X-ray bursts and centimeter radio bursts leads to a suggestion that the hard X-ray and centimeter radio bursts are generated by the same electrons. On the basis of these considerations one can more easily understand the homology of both the X-ray bursts and the radio bursts. The occurrence of homologous bursts then can be explained by an existence of regions on the sun in which for a certain time (48 h after Fokker) the same conditions are maintained in the acceleration of the electrons generating the X-ray and radio bursts.