Multi-Wavelength Photometric and Polarimetric Observations of the Outburst of 3C 454.3 in 2009 December

In 2009 December, the bright blazar 3C 454.3 exhibited a strong outburst in the optical, X-ray, and gamma-ray regions. We performed photometric and polarimetric monitoring of this outburst in the optical and near-infrared bands with TRISPEC and HOWPol attached to the Kanata telescope. We also observed this outburst in the infrared band with AKARI, and the radio band with the 32-m radio telescope of Yamaguchi University. The object was in an active state from JD 2455055 to 2455159. It was 1.3 mag brighter than its quiescent state before JD 2455055 in the optical band. After the end of the active state in JD 2455159, a prominent outburst was observed in all wavelengths. The outburst continued for two months. Our optical and near-infrared polarimetric observations revealed that the position angle of the polarization (PA) apparently rotated clockwise by 240° within 11 d in the active state (JD 2455063-2455074); after this rotation, PA remained almost constant during our monitoring. In the outburst state, PA smoothly rotated counterclockwise by 350° within 35 d (JD 2455157-2455192). Thus, we detected two distinct rotation events of polarization vectors in opposite directions. We discuss these two events compared with the past rotation events observed in 2005, 2007, and 2008.