Variations of the energy spectra of solar X-ray flares: interconnection with the photospheric, chromospheric, and magnetic activity of the Sun (1972−2001)

• Опубліковано в: : Кинематика и физика небесных тел
• Дата: 2005
• Автор: Kasinskii, V.
• Формат: Стаття
• Мова: English
• Опубліковано: Головна астрономічна обсерваторія НАН України 2005
• Теми: MS2: Physics of Solar Atmosphere
• Онлайн доступ: https://nasplib.isofts.kiev.ua/handle/123456789/79614
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Variations of the energy spectra of solar X-ray flares: interconnection with the photospheric, chromospheric, and magnetic activity of the Sun (1972−2001) / V. Kasinskii // Кинематика и физика небесных тел. — 2005. — Т. 21, № 5-додаток. — С. 105-109. — Бібліогр.: 5 назв. — англ.

The problem of flare energy distribution of the Sun is strongly related to the power-law energy spectra of flares on the UV Ceti-type stars. In a preliminary study (1972–1993), the X-ray flare integral energy spectrum (IES) was represented by a unique power law of N ~ E−b with index b = 0.76. Later it was shown that the exponent index b varies with the cycle phase, that is with the Wolf number. The purpose of this paper is to investigate the temporal variations in the power-law spectrum of soft X-ray flares over the three solar cycles (1972–2001). A more extensive statistic (56 000 flares) allows us to revise earlier results and to derive new ones. Not only b-index undergoes variations associated with a 11-year cycle but the limiting energy of flares (log Em) as well. The three-cycle-averaged b is 0.666, with variations in the range 0.50 < b < 0.80. The results may be useful for study of flare activity on red dwarf stars.