The flat-spectrum radio quasar 3C454.3 underwent an extraordinary 5 day γ-ray outburst in 2010 November when the daily flux measured with the Fermi Large Area Telescope (LAT) at photon energies E > 100MeV reached (66 2) × 10-6 photons cm-2 s-1. This is a factor of three higher than its previous maximum flux recorded in 2009 December and ≳ 5 times brighter than the Vela pulsar, which is normally the brightest source in the γ-ray sky. The 3hr peak flux was (85 5)×10-6 photons cm-2 s-1, corresponding to an apparent isotropic luminosity of (2.1 0.2)×1050 erg s-1, the highest ever recorded for a blazar. In this Letter, we investigate the features of this exceptional event in the γ-ray band of the Fermi-LAT. In contrast to previous flares of the same source observed with the Fermi-LAT, clear spectral changes are observed during the flare.
Fermi gamma-ray space telescope observations of the gamma-ray outburst from 3C454.3 in November 2010
FAVUZZI, Cecilia;GIGLIETTO, Nicola;
2011-01-01
Abstract
The flat-spectrum radio quasar 3C454.3 underwent an extraordinary 5 day γ-ray outburst in 2010 November when the daily flux measured with the Fermi Large Area Telescope (LAT) at photon energies E > 100MeV reached (66 2) × 10-6 photons cm-2 s-1. This is a factor of three higher than its previous maximum flux recorded in 2009 December and ≳ 5 times brighter than the Vela pulsar, which is normally the brightest source in the γ-ray sky. The 3hr peak flux was (85 5)×10-6 photons cm-2 s-1, corresponding to an apparent isotropic luminosity of (2.1 0.2)×1050 erg s-1, the highest ever recorded for a blazar. In this Letter, we investigate the features of this exceptional event in the γ-ray band of the Fermi-LAT. In contrast to previous flares of the same source observed with the Fermi-LAT, clear spectral changes are observed during the flare.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
