Long Baseline Polarimetry of 3 C 273 and 3 C 279 with the Coordinated Millimeter VLBI Array

86 GHz Very Long Baseline Polarimetry probes magnetic field structures within the cores of Active Galactic Nuclei at higher angular resolutions and a spectral octave higher than previously achievable. Observations of 3C 273 and 3C 279 taken in April 2000 with the Coordinated Millimeter VLBI Array have resulted in the first total intensity (Stokes I) and linear polarization VLBI images reported of any source at 86 GHz. These results reveal the 86 GHz electric vector position angles within the jets of 3C 273 and 3C 279 to be orthogonal to each other, and the core of 3C 273 to be unpolarized. If this lack of polarization is due to Faraday depolarization alone, the dispersion in rotation measure is &90000 rad m−2 for the core of 3C 273. Subject headings: galaxies: active—galaxies: jets—galaxies: magnetic fields—polarization— quasars: individual (3C 273, 3C 279)