Short duration solar microwave bursts and associated soft X-ray emission

✍ Scribed by Steven R. Spangler; Stanley D. Shawhan

• Publisher: Springer
• Year: 1974
• Tongue: English
• Weight: 765 KB
• Volume: 37
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00157856

✦ Synopsis

During the time period of November 1968 to March 1970, 259 15.4 GHz impulsive microwave bursts have been identified of which 147 had associated 2-12 A, soft X-ray bursts. Average durations, rise times, and decay times for the microwave bursts are 2.9 • 2.4 min, 0.9 :t: 0.8 min, and 2.2 i 2.1 rain, respectively.

Total durations and decay times for the X-ray events display a wide range of values from a few minutes to several hours. Rise times for 50 % of the events fell in the range of 2 to 7 min. A significant fraction (32 %) of the X-ray events may exhibit a flux enhancement prior to the main outburst.

For 85 % of the flare cases, the X-ray event begins simultaneously with or before the microwave event. In 91% of the cases the X-ray event peaks later than the microwave event. The average delay is 3.0 :t: 1.9 rain with 50 % of cases in the range of 0 to 4 rain.

The X-ray flux increases are significantly correlated with the microwave flux increases, having a correlation coefficient of 0.43 (> 99.9 % confident).