Late phase gradual enhancements in microwaves and hard X-rays of the 6 November 1980 flare

✍ Scribed by K. Kai; H. Nakajima; T. Kosugi; S. R. Kane

• Publisher: Springer
• Year: 1983
• Tongue: English
• Weight: 306 KB
• Volume: 86
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00157193

✦ Synopsis

Gradual enhancements which repeatedly appeared 20-50 min after the onset of an impulsive burst were observed in microwaves and hard X-rays.

The observed characteristics of the gradual enhancements are (i) the similarity of time profiles in both the frequency range of 17 GHz to 160 MHz and the energy range of 40 to ~400 keV, (ii) the low peak frequency of the microwave spectrum ( ~4 GHz ), and (iii) the flat X-ray spectrum with the power-law exponent of ~1.7.

It is suggested that the radio and X-ray gradual enhancements are due to a single population of energetic electrons which extend high in the corona ( at least 1.4x10 s km ). Nevertheless the 17 GHz source is likely to be at a low altitude, not much higher than the preceding impulsive burst source.