HIGH-ENERGY GAMMA-RAY EMISSION FROM SOLAR FLARES: SUMMARY OF FERMI LARGE AREA TELESCOPE DETECTIONS AND ANALYSIS OF TWO M-CLASS FLARES

被引：77

作者：

Ackermann, M. ^{[1
]}

Ajello, M. ^{[2
]}

Albert, A. ^{[3
]}

Allafort, A. ^{[4
,5
]}

Baldini, L. ^{[6
,7
]}

Barbiellini, G. ^{[8
,9
]}

Bastieri, D. ^{[10
,11
]}

Bechtol, K. ^{[4
,5
]}

Bellazzini, R. ^{[12
]}

Bissaldi, E. ^{[13
,14
]}

Bonamente, E. ^{[15
,16
]}

Bottacini, E. ^{[4
,5
]}

Bouvier, A. ^{[17
,18
]}

Brandt, T. J. ^{[19
]}

Bregeon, J. ^{[12
]}

Brigida, M. ^{[20
,21
]}

Bruel, P. ^{[22
]}

Buehler, R. ^{[4
,5
]}

Buson, S. ^{[10
,11
]}

Caliandro, G. A. ^{[23
]}

Cameron, R. A. ^{[4
,5
]}

Caraveo, P. A. ^{[24
]}

Cecchi, C. ^{[15
,16
]}

Charles, E. ^{[4
,5
]}

Chekhtman, A. ^{[25
]}

Chen, Q. ^{[4
,5
]}

Chiang, J. ^{[4
,5
]}

Chiaro, G. ^{[11
]}

Ciprini, S. ^{[26
,27
]}

Claus, R. ^{[4
,5
]}

Cohen-Tanugi, J. ^{[28
]}

Conrad, J. ^{[29
,30
,31
]}

Cutini, S. ^{[26
,27
]}

D'Ammando, F. ^{[32
]}

de Angelis, A. ^{[33
,34
]}

de Palma, F. ^{[20
,21
]}

Dermer, C. D. ^{[35
]}

Desiante, R. ^{[5
,8
]}

Digel, S. W. ^{[4
,5
]}

Di Venere, L. ^{[4
,5
]}

do Couto e Silva, E. ^{[4
,5
]}

Drell, P. S. ^{[4
,5
]}

Drlica-Wagner, A. ^{[4
,5
]}

Favuzzi, C. ^{[20
,21
]}

Fegan, S. J. ^{[22
]}

Focke, W. B. ^{[4
,5
]}

Franckowiak, A. ^{[4
,5
]}

Fukazawa, Y. ^{[36
]}

Funk, S. ^{[4
,5
]}

Fusco, P. ^{[20
,21
]}

机构：

[1] DESY, D-15738 Zeuthen, Germany

[2] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA

[3] Ohio State Univ, Ctr Cosmol & Astroparticle Phys, Dept Phys, Columbus, OH 43210 USA

[4] Stanford Univ, Dept Phys, Kavli Inst Particle Astrophys & Cosmol, WW Hansen Expt Phys Lab, Stanford, CA 94305 USA

[5] Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA

[6] Univ Pisa, I-56127 Pisa, Italy

[7] Ist Nazl Fis Nucl, I-56127 Pisa, Italy

[8] Ist Nazl Fis Nucl, I-34127 Trieste, Italy

[9] Univ Trieste, Dipartmento Fis, I-34127 Trieste, Italy

[10] Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy

[11] Univ Padua, Dipartimento Fis Astron G Galilei, I-35131 Padua, Italy

[12] Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy

[13] Leopold Franzens Univ Innsbruck, Inst Astro & Teilchenphys, A-6020 Innsbruck, Austria

[14] Leopold Franzens Univ Innsbruck, Inst Theoret Phys, A-6020 Innsbruck, Austria

[15] Ist Nazl Fis Nucl, Sez Perugia, I-06123 Perugia, Italy

[16] Univ Perugia, Dipartimento Fis, I-06123 Perugia, Italy

[17] Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Dept Phys, Santa Cruz, CA 95064 USA

[18] Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA

[19] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA

[20] Univ Bari, Dipartimento Fis M Merlin, I-70126 Bari, Italy

[21] Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy

[22] Ecole Polytech, Lab Leprince Ringuet, CNRS, IN2P3, F-91128 Palaiseau, France

[23] CSIC, Inst Ciencies Espai, IEEE, E-08193 Barcelona, Spain

[24] INAF Ist Astrofis Spaziale & Fis Cosm, I-20133 Milan, Italy

[25] George Mason Univ, Coll Sci, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA

[26] Agenzia Spaziale Italiana ASI Sci Data Ctr, I-00044 Rome, Italy

[27] Ist Nazl Astrofis, Osservatorio Astron Roma, I-00040 Rome, Italy

[28] Univ Montpellier 2, Lab Univ & Particules Montpellier, CNRS, IN2P3, F-34095 Montpellier, France

[29] Univ Stockholm, Dept Phys, SE-10691 Stockholm, Sweden

[30] Oskar Klein Ctr Cosmoparticle Phys, SE-10691 Stockholm, Sweden

[31] Royal Swedish Acad Sci, SE-10405 Stockholm, Sweden

[32] INAF Ist Radioastron, I-40129 Bologna, Italy

[33] Univ Udine, Dipartimento Fis, I-33100 Udine, Italy

[34] Ist Nazl Fis Nucl, Sez Trieste, Grp Collegato Udine, I-33100 Udine, Italy

[35] Naval Res Lab, Div Space Sci, Washington, DC 20375 USA

[36] Hiroshima Univ, Dept Phys Sci, Higashihiroshima, Hiroshima 7398526, Japan

[37] Univ Paris Diderot, CEA Saclay, Lab AIM, Serv Astrophys,CEA IRFU CNRS, F-91191 Gif Sur Yvette, France

[38] Kyoto Univ, Grad Sch Sci, Dept Astron, Sakyo Ku, Kyoto 6068502, Japan

[39] Royal Inst Technol KTH, Dept Phys, SE-10691 Stockholm, Sweden

[40] Univ Iceland, Inst Sci, IS-107 Reykjavik, Iceland

[41] CNRS, IRAP, F-31028 Toulouse 4, France

[42] Univ Toulouse, GAHEC, F-31100 Toulouse, France

[43] Univ Stockholm, Dept Astron, SE-10691 Stockholm, Sweden

[44] Ist Nazl Fis Nucl, Sez Torino, I-10125 Turin, Italy

[45] Univ Bordeaux 1, Ctr Etud Nucl Bordeaux Gradignan, CNRS, IN2P3, F-33175 Gradignan, France

[46] Univ Maryland, Dept Phys, College Pk, MD 20742 USA

[47] Univ Maryland, Dept Astron, College Pk, MD 20742 USA

[48] Hiroshima Univ, Hiroshima Astrophys Sci Ctr, Higashihiroshima, Hiroshima 7398526, Japan

[49] Ctr Res & Explorat Space Sci & Technol, Greenbelt, MD 20771 USA

[50] Ist Nazl Fis Nucl, Sez Roma Tor Vergata, I-00133 Rome, Italy

来源：

ASTROPHYSICAL JOURNAL | 2014年 / 787卷 / 01期

基金：

美国国家航空航天局; 瑞典研究理事会;

关键词：

Sun: flares; Sun:; X-rays; gamma rays; STOCHASTIC ACCELERATION; PARTICLE-ACCELERATION; EGRET; CALIBRATION; ELECTRONS; COMPTON; SHOCKS; WAVES; GRO;

D O I：

10.1088/0004-637X/787/1/15

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present the detections of 18 solar flares detected in high-energy gamma-rays (above 100 MeV) with the Fermi Large Area Telescope (LAT) during its first 4 yr of operation. This work suggests that particle acceleration up to very high energies in solar flares is more common than previously thought, occurring even in modest flares, and for longer durations. Interestingly, all these flares are associated with fairly fast coronal mass ejections (CMEs). We then describe the detailed temporal, spatial, and spectral characteristics of the first two long-lasting events: the 2011 March 7 flare, a moderate (M3.7) impulsive flare followed by slowly varying gamma-ray emission over 13 hr, and the 2011 June 7 M2.5 flare, which was followed by gamma-ray emission lasting for 2 hr. We compare the Fermi LAT data with X-ray and proton data measurements from GOES and RHESSI. We argue that the gamma-rays are more likely produced through pion decay than electron bremsstrahlung, and we find that the energy spectrum of the proton distribution softens during the extended emission of the 2011 March 7 flare. This would disfavor a trapping scenario for particles accelerated during the impulsive phase of the flare and point to a continuous acceleration process at play for the duration of the flares. CME shocks are known for accelerating the solar energetic particles (SEPs) observed in situ on similar timescales, but it might be challenging to explain the production of gamma-rays at the surface of the Sun while the CME is halfway to the Earth. A stochastic turbulence acceleration process occurring in the solar corona is another likely scenario. Detailed comparison of characteristics of SEPs and gamma-ray-emitting particles for several flares will be helpful to distinguish between these two possibilities.

引用

页数：13

共 31 条

[21] Stochastic acceleration of electrons and protons. I. Acceleration by parallel-propagating waves [J].