Submilliarcsecond polarimetric imaging of blazar jets at 43 GHz

We present 43 GHz polarization images obtained with the Very Long Baseline Array of four blazars (0829 + 046, 1055 + 018, 1334-127, and AP Librae), as well as four active galactic nuclei, which served as polarization calibrat ors (DA 193, OJ 287, 3C 279, and 1611 + 343). Six of these objects are memb ers of the Nartallo et al. millimeter-wave polarization blazar monitoring s ample. We find no differences in the overall millimeter-wave polarization p roperties of the BL Lacertae objects and quasars in our sample. This is in contrast to previous findings at centimeter wavelengths, in which the infer red magnetic fields of quasars are found to be predominantly aligned with t he jet, while perpendicular configurations are found in BL Lac objects. Wit h the exception of 1611 + 343, a low optical polarization quasar, all of th e unresolved blazar cores in our sample have inferred magnetic held orienta tions perpendicular to the inner jet direction. Past nonimaging millimeter- wave polarization monitoring data have shown that these core orientations a re stable in three of our sample objects; this may be due to strong, unreso lved standing shocks located very close to the base of the jet. We also det ect in the jets of blazars a moderate-sized population of polarized compone nts having electric vectors that lie at an oblique angle to the local jet d irection. We find that the observed distribution of electric vector misalig nment angles cannot be fitted by a single population of oblique shocks havi ng arbitrary inclinations with respect to the jet axis. Such a population p redicts an overabundance of shocks with electric polarization vectors align ed with the jet axis, produced by relativistic effects associated with the jet how. We find the data to be more consistent with a scenario in which th e polarized jet components are merely enhanced regions whose magnetic held orientations are controlled by some mechanism other than shocks.