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.

Fermi-large area telescope observations of the exceptional gamma-ray outbursts of 3C 273 in 2009 September / Abdo, A.a., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R.d., Bloom, E.d., Bonamente, E., Borgland, A.w., Bouvier, A., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Burnett, T.h., et al.. - In: THE ASTROPHYSICAL JOURNAL LETTERS. - ISSN 2041-8205. - 714:1(2010), pp. L73-L78. [10.1088/2041-8205/714/1/L73]

Fermi-large area telescope observations of the exceptional gamma-ray outbursts of 3C 273 in 2009 September

FAVUZZI, Cecilia;GIGLIETTO, Nicola;
2010

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.
2010
Fermi-large area telescope observations of the exceptional gamma-ray outbursts of 3C 273 in 2009 September / Abdo, A.a., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R.d., Bloom, E.d., Bonamente, E., Borgland, A.w., Bouvier, A., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Burnett, T.h., et al.. - In: THE ASTROPHYSICAL JOURNAL LETTERS. - ISSN 2041-8205. - 714:1(2010), pp. L73-L78. [10.1088/2041-8205/714/1/L73]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11589/71
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