Optical Polarization Variability in Blazars
Presented by Vasiliki Pavlidou
University of Crete
Wednesday, September 2, 2015
2:00 P.M. in 169-336
RoboPol is the first monitoring program of an unbiased sample of gamma-ray bright braziers, specifically designed for the effective detection and robust statistics of polarization swings in blazar synchrotron emission at optical wavelengths. Since the launch of the Fermi satellite, it has been suggested that such events may be physically connected with periods of high gamma-ray activity in blazars. Alternatively, the polarization variability in blazars may be erratic, and polarization swings may be produced by chance in an underlying random walk of the polarization vector. We discuss results of the first season of RoboPol monitoring, and how they weigh in on these questions. Some highlights from our findings are: 1 )It is highly unlikely (at the >4sigma level) that none of the rotations observed by RoboPol is physically connected with gamma ray flares. 2) We find indications that more than one mechanisms may be responsible for polarization swings. 3) Blazars with detected rotations have significantly different polarization variability properties than blazars that have never exhibited a rotation.
JPL Contact: Harold Yorke (4-5515)