The 20 January 2005 big proton event and relations between microwave bursts and proton fluxes

V.V. Grechnev$^1$, V.G. Kurt$^2$, I.M. Chertok$^3$, A.M. Uralov$^1$, H. Nakajima$^4$, A.T. Altyntsev$^1$, A.V. Belov$^3$, B.Y. Yushkov$^2$, S.N. Kuznetsov$^2$, L.K. Kashapova$^1$, N.S. Meshalkina$^1$, N.P. Prestage$^5$

$^1$Institute of Solar-Terrestrial Physics SB RAS, Lermontov St. 126, Irkutsk 664033, Russia
$^2$Skobeltsyn Institute of Nuclear Physics Moscow State University, Moscow, 119992 Russia
$^3$ Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation (IZMIRAN), Troitsk, Moscow Region, 142190 Russia
$^4$Nobeyama Radio Observatory, National Astronomical Observatory of Japan, Minamimaki, Minamisaku, Nagano 384-1305, Japan
$^5$IPS Radio and Space Services Culgoora Solar Observatory, Australia

We address the major flare/CME/GLE event of January 20, 2005 on the basis of multi-spectral data, first, to understand this remarkable flare and physical conditions in the flare region. Second, we endeavor to find an answer for a long-standing contest about origination of solar energetic particles, which appear near Earth; acceleration in the flare or by a CME-driven shock. The results constitute a self-consistent picture of the flare, which occurred within a closed configuration just above sunspots, where accelerated particles have no access from outside. Careful investigation of the CME shows that it had no pronounced differences with its predecessors from the same active region, and its speed ranged between 2000 and 2600 km/s. At the same time, a huge burst was observed in microwaves and millimeters. Thus, just the flare rather than CME determined extremeness of this event. Moreover, the impulsive leading parts of the GLE and high-energy gamma-rays were strikingly similar and well corresponded to each other in time. Our conclusion is that acceleration of particles responsible for both the flare emissions and SEP/GLE occurred simultaneously within the flare region, rather than in the CME-driven shock. We then verify our conclusion by overview of major microwave and proton events and find this correlation to be well-pronounced for their majority. A distinctive feature of these events is flare occurrence just above or close to sunspots' umbrae.