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Title: FERMI-LARGE AREA TELESCOPE OBSERVATIONS OF THE EXCEPTIONAL GAMMA-RAY OUTBURSTS OF 3C 273 IN 2009 SEPTEMBER

Abstract

We present the light curves and spectral data of two exceptionally luminous gamma-ray outbursts observed by the Large Area Telescope experiment on board the Fermi Gamma-ray Space Telescope from 3C 273 in 2009 September. During these flares, having a duration of a few days, the source reached its highest {gamma}-ray flux ever measured. This allowed us to study, in some details, their spectral and temporal structures. The rise and the decay are asymmetric on timescales of 6 hr, and the spectral index was significantly harder during the flares than during the preceding 11 months. We also found that short, very intense flares put out the same time-integrated energy as long, less intense flares like that observed in 2009 August.

Authors:
 [1]; ; ; ; ; ; ; ;  [2]; ; ; ;  [3];  [4];  [5];  [6];  [7];  [8];  [9];  [10]
  1. Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)
  2. W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)
  3. Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy)
  4. Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d'Astrophysique, CEA Saclay, 91191 Gif sur Yvette (France)
  5. Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy)
  6. Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy)
  7. Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy)
  8. Dipartimento di Fisica 'M. Merlin' dell'Universita e del Politecnico di Bari, I-70126 Bari (Italy)
  9. Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, Palaiseau (France)
  10. Department of Physics, University of Washington, Seattle, WA 98195-1560 (United States), E-mail: gino.tosti@pg.infn.it, E-mail: enrico.massaro@uniroma1.it (and others)
Publication Date:
OSTI Identifier:
21305002
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 714; Journal Issue: 1; Other Information: DOI: 10.1088/2041-8205/714/1/L73; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; 99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; ASYMMETRY; GALAXIES; GAMMA RADIATION; QUASARS; TELESCOPES

Citation Formats

Abdo, A. A., Ackermann, M., Ajello, M., Bechtol, K., Berenji, B., Blandford, R. D., Bloom, E. D., Borgland, A. W., Bouvier, A., Baldini, L., Bellazzini, R., Bregeon, J., Brez, A., Ballet, J., Barbiellini, G., Bastieri, D., Bonamente, E., Brigida, M., Bruel, P., and Burnett, T. H. FERMI-LARGE AREA TELESCOPE OBSERVATIONS OF THE EXCEPTIONAL GAMMA-RAY OUTBURSTS OF 3C 273 IN 2009 SEPTEMBER. United States: N. p., 2010. Web. doi:10.1088/2041-8205/714/1/L73; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
Abdo, A. A., Ackermann, M., Ajello, M., Bechtol, K., Berenji, B., Blandford, R. D., Bloom, E. D., Borgland, A. W., Bouvier, A., Baldini, L., Bellazzini, R., Bregeon, J., Brez, A., Ballet, J., Barbiellini, G., Bastieri, D., Bonamente, E., Brigida, M., Bruel, P., & Burnett, T. H. FERMI-LARGE AREA TELESCOPE OBSERVATIONS OF THE EXCEPTIONAL GAMMA-RAY OUTBURSTS OF 3C 273 IN 2009 SEPTEMBER. United States. doi:10.1088/2041-8205/714/1/L73; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
Abdo, A. A., Ackermann, M., Ajello, M., Bechtol, K., Berenji, B., Blandford, R. D., Bloom, E. D., Borgland, A. W., Bouvier, A., Baldini, L., Bellazzini, R., Bregeon, J., Brez, A., Ballet, J., Barbiellini, G., Bastieri, D., Bonamente, E., Brigida, M., Bruel, P., and Burnett, T. H. Sat . "FERMI-LARGE AREA TELESCOPE OBSERVATIONS OF THE EXCEPTIONAL GAMMA-RAY OUTBURSTS OF 3C 273 IN 2009 SEPTEMBER". United States. doi:10.1088/2041-8205/714/1/L73; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
@article{osti_21305002,
title = {FERMI-LARGE AREA TELESCOPE OBSERVATIONS OF THE EXCEPTIONAL GAMMA-RAY OUTBURSTS OF 3C 273 IN 2009 SEPTEMBER},
author = {Abdo, A. A. and Ackermann, M. and Ajello, M. and Bechtol, K. and Berenji, B. and Blandford, R. D. and Bloom, E. D. and Borgland, A. W. and Bouvier, A. and Baldini, L. and Bellazzini, R. and Bregeon, J. and Brez, A. and Ballet, J. and Barbiellini, G. and Bastieri, D. and Bonamente, E. and Brigida, M. and Bruel, P. and Burnett, T. H.},
abstractNote = {We present the light curves and spectral data of two exceptionally luminous gamma-ray outbursts observed by the Large Area Telescope experiment on board the Fermi Gamma-ray Space Telescope from 3C 273 in 2009 September. During these flares, having a duration of a few days, the source reached its highest {gamma}-ray flux ever measured. This allowed us to study, in some details, their spectral and temporal structures. The rise and the decay are asymmetric on timescales of 6 hr, and the spectral index was significantly harder during the flares than during the preceding 11 months. We also found that short, very intense flares put out the same time-integrated energy as long, less intense flares like that observed in 2009 August.},
doi = {10.1088/2041-8205/714/1/L73; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 714,
place = {United States},
year = {2010},
month = {5}
}