SUB-THz AND H-ALPHA ACTIVITY DURING THE PREFLARE AND MAIN PHASES OF A GOES CLASS M2 EVENT

PIERRE KAUFMANN; ROGÉRIO MARCON; C. GUILLERMO GIMÉNEZ DE CASTRO; STEPHEN M. WHITE; JEAN-PIERRE RAULIN; EMILIA CORREIA; LUIS OLAVO FERNANDES; RODNEY V. DE SOUZA; RODOLFO GODOY; ADOLFO MARUN; PABLO PEREYRA

ASTROPHYSICAL JOURNAL

IOP PUBLISHING LTD

Lugar: Londres; Año: 2011 vol. 742 p. 106 - 110

0004-637X

Radio and optical observations of the evolution of flare-associated Phenomena have shown an initial and rapid burst at 0.4 THz only followed subsequently by a localized chromospheric heating producing an Hα Brightening with later heating of the whole active region. A major instability occurred several minutes later producing one impulsive burst at microwaves only, associated with an M2.0 GOES X-ray flare that exhibited the main Hα brightening at the same site as the first flash.The possible association between long-enduring time profiles at soft X-rays, microwaves, Hα, and sub-THz wavelengths is discussed. In the decay phase, the Hα movie shows a disrupting magnetic arch structure ejecting dark, presumably chromospheric, material upward. The time sequence of events suggests genuine interdependent and possibly non-thermal instabilities triggering phenomena, with concurrent active region plasma heating and material ejection.