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Projeto Observacional para 2008B - OP2008B-006

Autor: Zulema Abraham
Instituição: IAG
e-mail: zulema@astro.iag.usp.br

Ulisses Barres de ALMEIDA
Tania Pereira Dominici
Catherine BOISSON
Alberto Rodriguez-Ardila
Martin Ward
Paula Chadwick
Jean-Phillippe Lenain

Título: Multiband Optical Polarimetric Observations of the TeV Blazar PKS 2155-304 simultaneous with a HESS/GLAST/RXTE High-Energy (HE) Multiwavelength Campaign.

Resumo: PKS 2155-304 is one of the best studied high-energy blazars. Its brightness and extreme variability over the whole SED make it an ideal source for probing the processes responsible for variable emission in AGN. Rapidly changing fluxes make simultaneous observations necessary to model the SED of this kind of source. This is the first time that a multiwavelength campaign will simultaneously cover the whole of the HE portion of an AGN’s SED, from X-rays to TeVs. In order to properly constrain the emission models, however, it is necessary to link the properties of the HE emission to the behavior of the lower energy radiation. Below the UV range, ordinary absolute flux data fail to provide a clear picture of the expected correlated variability. Past sparse optical observations of HBLs and recent data collected on PKS 2155-304 at this observatory, contemporaneous to X-ray data, hint however at a possible correlation between changes on the polarized optical flux and angle, and the HE flux variability. We propose to conduct observations, simultaneously with this already-scheduled HE campaign, in order to confirm the observational signatures that would link, for the first time, the low and high-energy emissions from this blazar.