Fermi-LAT Observations of the 2014 May-July outburst from 3C 454.3

Richard J. G. Britto; Eugenio Bottacini; Benoît Lott; Soebur Razzaque; Sara Buson

doi:10.3847/0004-637X/830/2/162

paper

Fermi-LAT Observations of the 2014 May-July outburst from 3C 454.3

arXiv:1511.02280 · doi:10.3847/0004-637X/830/2/162

Abstract

A prominent outburst of the flat spectrum radio quasar 3C~454.3 was observed in 2014 June with the \emph{Fermi} Large Area Telescope. This outburst was characterized by a three-stage light-curve pattern---plateau, flare and post-flare---that occurred from 2014 May to July, in a similar pattern as observed during the exceptional outburst in 2010 November. The highest flux of the outburst reported in this paper occurred during 2014 June 7--29, showing a multiple-peak structure in the light-curves. The average flux in these 22 days was found to be $F [E > 100 MeV] = (7.2 \pm 0.2) \times 1 0^{- 6}$ ~ph~cm $^{- 2}$ ~s $^{- 1}$ , with a spectral index, for a simple power law, of $Γ = 2.04 \pm 0.01$ . That made this outburst the first $γ$ -ray high state of 3C~454.3 ever to be detected by \emph{Fermi} with such a hard spectrum over several days. The highest flux was recorded on 2014 June 15, in a 3 hr bin, at MJD 56823.5625, at a level of $F [E > 100 MeV] = (17.6 \pm 1.9) \times 1 0^{- 6}$ ~ph~cm $^{- 2}$ ~s $^{- 1}$ . The rise time of one of the short subflares was found to be $T_{r} = 1200 \pm 700$ ~s at MJD = 56827, when the flux increased from 4 to 12 $\times 1 0^{- 6}$ ~ph~cm $^{- 2}$ ~s $^{- 1}$ . Several photons above 20 GeV were collected during this outburst, including one at 45 GeV on MJD 56827, constraining the $γ$ -ray emission region to be located close to the outer boundary of the broad-line region, leading to fast flux variability.

Accepted for publication in {\sc the astrophysical journal}: 2016 July 12}; 15 pages, 7 figures, 6 tables

Fermi-LAT Observations of the 2014 May-July outburst from 3C 454.3

Abstract

References in corpus (11)

Cited by in corpus (33)