Fermi Detection of γ-Ray Emission from the M2 Soft X-Ray Flare on 2010 June 12

Markus Ackermann , Marco Ajello , A. Allafort , W. B. Atwood , Luca Baldini , Guido Barbiellini , D. Bastieri , K. Bechtol , R. Bellazzini , P. N. Bhat , R. D. Blandford , E. Bonamente , A. W. Borgland , J. Bregeon , M. S. Briggs , M. Brigida , Pascal Bruel (1) , R. Buehler , J. M. Burgess , S. Buson , G. A. Caliandro , R. A. Cameron , J. M. Casandjian (2) , C. Cecchi , E. Charles , A. Chekhtman , J. Chiang , S. Ciprini , R. Claus , J. Cohen-Tanugi (3) , V. Connaughton , J. Conrad , S. Cutini , B. R. Dennis , F. de Palma , C. D. Dermer , S. W. Digel , E. Silva , P. S. Drell , A. Drlica-Wagner , R. Dubois , C. Favuzzi , S. J. Fegan (1) , E. C. Ferrara , P. Fortin (1) , Y. Fukazawa , P. Fusco , F. Gargano , S. Germani , N. Giglietto , F. Giordano , M. Giroletti , T. Glanzman , G. Godfrey , L. Grillo , J. E. Grove , D. Gruber , S. Guiriec , D. Hadasch , M. Hayashida , E. Hays , D. Horan (1) , G. Iafrate , G. Jóhannesson , A. S. Johnson , W. N. Johnson , T. Kamae , R. M. Kippen , Jürgen Knödlseder (4) , M. Kuss , J. Lande , L. Latronico , F. Longo , F. Loparco , B. Lott (5) , M. N. Lovellette , P. Lubrano , M. N. Mazziotta , J. E. Mcenery , C. Meegan , J. Mehault (3) , P. F. Michelson , W. Mitthumsiri , C. Monte , M. E. Monzani , A. Morselli , I. V. Moskalenko , S. Murgia , R. Murphy , M. Naumann-Godo (2) , E. Nuss (3) , T. Nymark , M. Ohno , T. Ohsugi , A. Okumura , N. Omodei , E. Orlando , W. S. Paciesas , J. H. Panetta , D. Parent , M. Pesce-Rollins , V. Petrosian , M. Pierbattista (2) , F. Piron (3) , G. Pivato , H. Poon , T.A. Porter , R. Preece , S. Rainò , R. Rando , M. Razzano , S. Razzaque , A. Reimer , O. Reimer , S. Ritz , C. Sbarra , R.A. Schwartz , C. Sgrò , G. H. Share , E. J. Siskind , P. Spinelli , H. Takahashi , T. Tanaka , Y. Tanaka , J. B. Thayer , L. Tibaldo , M. Tinivella , A. K. Tolbert , G. Tosti , E. Troja , Y. Uchiyama , T. L. Usher , J. Vandenbroucke , V. Vasileiou (3) , G. Vianello , V. Vitale , A. von Kienlin , A. P. Waite , C. Wilson-Hodge , D. L. Wood , K. S. Wood , Z. Yang

1 LLR - Laboratoire Leprince-Ringuet
2 AIM (UMR7158 / UMR_E_9005 / UM_112) - Astrophysique Interprétation Modélisation
3 LUPM - Laboratoire Univers et Particules de Montpellier
4 IRAP - Institut de recherche en astrophysique et planétologie
5 GLAST

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 ~50 s impulsive burst of hard X- and γ-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 γ-ray time profiles suggest that most of the particles were accelerated to energies gsim300 MeV with a delay of ~10 s from mildly relativistic electrons, but some reached these energies in as little as ~3 s. The γ-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 γ-rays.

Mots clés: acceleration of particles; Sun: flares; Sun: particle emission; Sun: X-rays; gamma rays

Domaines: Phénomènes cosmiques de haute energie [astro-ph.HE]; Phénomènes cosmiques de haute energie [astro-ph.HE]

Markus Ackermann, Marco Ajello, A. Allafort, W. B. Atwood, Luca Baldini, et al.. Fermi Detection of γ-Ray Emission from the M2 Soft X-Ray Flare on 2010 June 12. The Astrophysical Journal, 2012, 745, pp.144. ⟨10.1088/0004-637X/745/2/144⟩. ⟨in2p3-00684631⟩