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Fermi Large Area Telescope observation of high-energy solar flares: constraining emission scenarios

Published online by Cambridge University Press:  09 September 2016

Nicola Omodei
Affiliation:
Stanford University and KIPAC email: [email protected]
Melissa Pesce-Rollins
Affiliation:
Stanford University and KIPAC email: [email protected] INFN Pisa, Italy
Vahè Petrosian
Affiliation:
Stanford University and KIPAC email: [email protected]
Wei Liu
Affiliation:
Stanford University and KIPAC email: [email protected]
Fatima Rubio da Costa
Affiliation:
Stanford University and KIPAC email: [email protected]
Alice Allafort
Affiliation:
Stanford University and KIPAC email: [email protected]
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Abstract

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The Fermi Large Area Telescope (LAT) is the most sensitive instrument ever deployed in space for observing gamma-ray emission >100 MeV. This has also been demonstrated by its detection of quiescent gamma-ray emission from pions produced by cosmic-ray protons interacting in the solar atmosphere, and from cosmic-ray electron interactions with solar optical photons. The Fermi-LAT has also detected high-energy gamma-ray emission associated with GOES M-class and X-class solar flares, each accompanied by a coronal mass ejection and a solar energetic particle event, increasing the number of detected solar flares by almost a factor of 10 with respect to previous space observations. During the impulsive phase, gamma rays with energies up to several hundreds of MeV have been recorded by the LAT. Emission up to GeV energies lasting several hours after the flare has also been detected by the LAT. Of particular interest are the recent detections of three solar flares whose position behind the limb was confirmed by the STEREO satellites. While gamma-ray emission up to tens of MeV resulting from proton interactions has been detected before from occulted solar flares, the significance of these particular events lies in the fact that these are the first detections of >100 MeV gamma-ray emission from footpoint-occulted flares. We will present the Fermi-LAT, RHESSI and STEREO observations of these flares and discuss the various emission scenarios for these sources.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2016 

References

Abdo, A. A., Ackermann, M., Ajello, M., et al. 2011a, ApJ, 734, 116 CrossRefGoogle Scholar
Abdo, A. A., Ackermann, M., Ajello, M., et al. 2011b, ApJ, 734, 116 CrossRefGoogle Scholar
Ackermann, M., Ajello, M., Allafort, A., et al. 2012, ApJ, 745, 144 CrossRefGoogle Scholar
Ackermann, M., Ajello, M., Albert, A., et al. 2014, The Astrophysical Journal, 787, 15 CrossRefGoogle Scholar
Ajello, M. A. A., Allafort, A., Baldini, L., et al. 2014, The Astrophysical Journal, 789, 20 CrossRefGoogle Scholar
Atwood, W. B., Abdo, A. A., Ackermann, M., Ajello, M., et al. 2009, ApJ, 697, 1071 CrossRefGoogle Scholar
Barat, C., Trottet, G., Vilmer, N., et al. 1994, ApJ, 425, L109 CrossRefGoogle Scholar
Cliver, E. W., Kahler, S. W., & et al. 1993, in International Cosmic Ray Conference, Vol. 3, International Cosmic Ray Conference, 91–+Google Scholar
Kelly, J., Dalla, S., & Laitinen, T. 2012, ApJ, 750, 47 CrossRefGoogle Scholar
Meegan, C., Lichti, G., Bhat, P. N., et al. 2009, ApJ, 702, 791 CrossRefGoogle Scholar
Nitta, N. V., Aschwanden, M. J., Boerner, P. F., et al. 2013, Sol. Phys., 288, 241 CrossRefGoogle Scholar
Pesce-Rollins, M., Omodei, N., Petrosian, V., et al. 2015, ApJ, 805, L15 CrossRefGoogle Scholar
Petrosian, V., & Liu, S. 2004, ApJ, 610, 550 CrossRefGoogle Scholar
Ramaty, R., Murphy, R. J., & Dermer, C. D. 1987, ApJ, 316, L41 CrossRefGoogle Scholar
Ryan, J. M. 2000, Space Sci. Rev., 93, 581 CrossRefGoogle Scholar
Vestrand, W. T., & Forrest, D. J. 1993, ApJ, 409, L69 CrossRefGoogle Scholar
Vilmer, N., Trottet, G., Barat, C., et al. 1999, A&A, 342, 575 Google Scholar