Download or read book Correlated Multiwavelength Polarization in Blazars written by Francesca D. D'arcangelo and published by . This book was released on 2010 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The class of active galactic nuclei termed 'blazars' displays dynamic plasma jets aligned close to the line of sight of the observer. The launching, collimation, acceleration to relativistic flow speeds, and sustainment of these powerful jets is a primary current question in astrophysics. Multiwavelength observations, which probe within a few parsecs of the supermassive black hole, can reveal the mechanisms behind this emission. Blazar jets are well-observed at radio wavelengths; the angular resolution at 43 GHz with the Very Long Baseline Array corresponds to less than a parsec for many objects. We can examine flux density and polarization data to gain insight into the magnetic field alignment, jet shape, knot speeds, and other physical properties. However, at optical wavelengths, blazars are only resolved on a length scale of kiloparsecs. Thus, the location of higher-frequency emission on parsec scales needs to be inferred rather than directly observed. A new technique allows a connection to be made between high-frequency emission and the parsec-scale jet by comparison of polarization characteristics. If the optical electric vector position angle (EVPA) value is close to that of a feature in the radio jet, we can conclude that the emission at both wavelengths is produced by the same mechanism in the same general location. Our work expands this technique by using measurements of time variability during two intensive 10-day multiwavelength campaigns. The study of this data set determines the correlation in variability between the optical EVPA and that at 43 GHz in the parsec-scale jet. This dissertation establishes cospatiality of optical emission with the stationary core seen in 43 GHz images for the majority of our sample of 20 blazars by finding that the EVPAs of the two wavebands agree in value as well as in the timing and manner of their variation. The work then focuses on the magnetic field structure in and around the blazar core. A model is constructed for the production of polarization in each object, and these models are compared to determine the physical nature and structure of the core for blazars as a whole.