Correlated variability in the blazar 3C 454.3

Autor: Bonning, E. W., Bailyn, C., Urry, C. M., Buxton, M., Fossati, G., Maraschi, L., Coppi, P., Scalzo, R., Isler, J., Kaptur, A.
Rok vydání: 2008
Předmět:
Zdroj: Astrophys.J.697:L81-L85,2009
Druh dokumentu: Working Paper
DOI: 10.1088/0004-637X/697/2/L81
Popis: The blazar 3C 454.3 was revealed by the Fermi Gamma-ray Space Telescope to be in an exceptionally high flux state in July 2008. Accordingly, we performed a multi-wavelength monitoring campaign on this blazar using IR and optical observations from the SMARTS telescopes, optical, UV and X-ray data from the Swift satellite, and public-release gamma-ray data from Fermi. We find an excellent correlation between the IR, optical, UV and gamma-ray light curves, with a time lag of less than one day. The amplitude of the infrared variability is comparable to that in gamma-rays, and larger than at optical or UV wavelengths. The X-ray flux is not strongly correlated with either the gamma-rays or longer wavelength data. These variability characteristics find a natural explanation in the external Compton model, in which electrons with Lorentz factor gamma~10^(3-4) radiate synchrotron emission in the infrared-optical and also scatter accretion disk or emission line photons to gamma-ray energies, while much cooler electrons (gamma~10^(1-2)) produce X-rays by scattering synchrotron or other ambient photons.
Comment: 7 pages, 3 figures, submitted to ApJ Letters
Databáze: arXiv