Masanori Nishio et al. 1997 ApJ 489 976 doi:10.1086/304793
Masanori Nishio1, Kentaro Yaji2,3, Takeo Kosugi1, Hiroshi Nakajima1 and Takashi Sakurai2
Show affiliationsThe results of an analysis of 14 impulsive solar flares, observed simultaneously with microwave and X-ray imaging instruments, are presented. From the relative locations of microwave, hard X-ray, and soft X-ray sources, we have found that in 10 of the 14, at least two loops are involved. Typical sizes of the two loops differ; one is typically ≤20'' and the other 30''-80''. Microwave emission is detected from both loops, while hard X-ray emission is preferentially radiated from the shorter of the two loops. The shorter loop is brighter than the longer loop in soft X-rays. However, intensity variations of microwaves from the two loops are similar. These observations, together with comparisons of the microwave/X-ray images with photospheric magnetograms, suggest that in the majority of impulsive flare events two loops interact with each other, releasing magnetic energy and producing energetic electrons. The observations are therefore consistent with the emerging flux model of flares.
acceleration of particles; Sun: flares; Sun: radio radiation; Sun: X-rays, gamma rays
Issue 2 (1997 November 10)
Received 1996 October 18, accepted for publication 1997 June 2
Masanori Nishio et al. 1997 ApJ 489 976