FERMI DETECTION OF gamma-RAY EMISSION FROM THE M2 SOFT X-RAY FLARE ON 2010 JUNE 12

Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W. B.; Baldini, L.; Barbiellini, G.; Bastieri, Denis; Bechtol, K.; Bellazzini, R.; Bhat, P. N.; Blandford, R. D.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Briggs, M. S.; Brigida, M.; Bruel, P.; Buehler, R.; Burgess, J. M.; Buson, Sara; Caliandro, G. A.; Cameron, R. A.; Casandjian, J. M.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen Tanugi, J.; Connaughton, V.; Conrad, J.; Cutini, S.; Dennis, B. R.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Silva, E. do Couto e.; Drell, P. S.; Drlica Wagner, A.; Dubois, R.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Fortin, P.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grillo, L.; Grove, J. E.; Gruber, D.; Guiriec, S.; Hadasch, D.; Hayashida, M.; Hays, E.; Horan, D.; Iafrate, G.; Johannesson, G.; Johnson, A. S.; Johnson, W. N.; Kamae, T.; Kippen, R. M.; Knoedlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Mazziotta, M. N.; Mcenery, J. E.; Meegan, C.; Mehault, J.; Michelson, P. F.; Mitthumsiri, W.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Murphy, R.; Naumann Godo, M.; Nuss, E.; Nymark, T.; Ohno, M.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Paciesas, W. S.; Panetta, J. H.; Parent, D.; Pesce Rollins, M.; Petrosian, V.; Pierbattista, M.; Piron, F.; Pivato, G.; Poon, H.; Porter, T. A.; Preece, R.; Raino, S.; Rando, Riccardo; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Ritz, S.; Sbarra, C.; Schwartz, R. A.; Sgro, C.; Share, G. H.; Siskind, E. J.; Spinelli, P.; Takahashi, H.; Tanaka, T.; Tanaka, Y.; Thayer, J. B.; Tibaldo, Luigi; Tinivella, M.; Tolbert, A. K.; Tosti, G.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; von Kienlin, A.; Waite, A. P.; Wilson Hodge, C.; Wood, D. L.; Wood, K. S.; Yang, Z.

doi:10.1088/0004-637X/745/2/144

The Geostationary Operational Environmental Satellite (GOES) M2-class solar flare, SOL2010-06-12T00: 57, was modest in many respects yet exhibited remarkable acceleration of energetic particles. The flare produced an similar to 50 s impulsive burst of hard X-and gamma-ray emission up to at least 400 MeV observed by the Fermi Gamma-ray Burst Monitor and Large Area Telescope experiments. The remarkably similar hard X-ray and high-energy gamma-ray time profiles suggest that most of the particles were accelerated to energies greater than or similar to 300 MeV with a delay of similar to 10 s from mildly relativistic electrons, but some reached these energies in as little as similar to 3 s. The gamma-ray line fluence from this flare was about 10 times higher than that typically observed from this modest GOES class of X-ray flare. There is no evidence for time-extended >100 MeV emission as has been found for other flares with high-energy gamma-rays.