AVS-F observations of γ-ray emission during January 20, 2005 solar flare up to 140 MeV

• Published in: Advances in space research Vol. 43; no. 4; pp. 589 - 593
• Main Authors: Arkhangelskaja, I.V., Arkhangelsky, A.I., Kotov, Yu.D., Kalmykov, P.A., Glyanenko, A.S.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 16-02-2009
• Subjects: 20 January 2005 proton event; CORONAS-F; Solar activity; γ-Ray emission; Solar activity; 20 January 2005 proton event; CORONAS-F; γ-Ray emission
• ISSN: 0273-1177; 1879-1948
• DOI: 10.1016/j.asr.2008.11.016

The solar flare of January 20, 2005 (X7.1, 06:36–07:26 UT, maximum at 07:01 UT by the GOES soft X-ray data) was the most powerful one in January 2005 series. The AVS-F apparatus onboard CORONAS-F registered γ-emission during soft X-ray rising phase of this flare in two energy ranges of 0.1–20
MeV and 2–140
MeV. The highest γ-ray energy registered during this flare was ∼140
MeV. Six spectral features were registered in energy spectrum of this solar flare: annihilation
+
αα (0.4–0.6 MeV),
24Mg
+
20Ne
+
28Si
+
neutron capture (1.7–2.3
MeV),
21Ne
+
22Ne
+
16O
+
12С (3.2–5.0
MeV),
16O (5.3–6.9
MeV), one from neutral pions decay (25–110
MeV) and one in energy band 15–21
MeV. Four of them contain typical for solar flares lines – annihilation, nuclear de-excitation and neutron capture at
1H. Spectral feature caused by neutral pions decay was registered during several flares too. Some spectral peculiarities in the region of 15–21
MeV were first observed in solar flare energy spectrum.