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		| Paper: | 
		Variability in the Blazar 3C 454.3 | 
	 
	
		| Volume: | 
		427, Accretion and Ejection in AGN: a Global View | 
	 
	
		| Page: | 
		265 | 
	 
	
		| Authors: | 
		Bonning, E. W.; Bailyn, C.; Urry, C. M.; Buxton, M.; Fossati, G.; Maraschi, L.; Coppi, P.; Isler, J. | 
	 
	
	
		| Abstract: | 
		The blazar 3C 454.3 was revealed by Fermi Space Telescope to be in an
 exceptionally high flux state in July 2008. We performed a
 multi-wavelength monitoring campaign from August to December 2008 and 2009
 on this blazar using IR and optical observations from the SMARTS
 telescopes together with publicly available data from Swift and daily
 gamma-ray fluxes from Fermi. We find an excellent correlation between
 the infrared (IR), optical, ultraviolet (UV) and gamma-ray light curves,  
 with a time lag of less than one day. The amplitude of the infrared
 variability is larger than at optical or UV wavelengths, and the
 optical and IR emission shows redder colors at higher flux levels,
 consistent with an underlying thermal accretion disk. The variability
 characteristics of 3C 454.3 suggest an external Compton model in which
 electrons with Lorentz factor γ ∼103–4 produce
 synchrotron emission peaking in the IR while inverse Compton
 scattering disk or line photons to GeV energies. | 
	 
	
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