FIRST DETECTION OF 350 MICRON POLARIZATION FROM A RADIO-LOUD AGN

We report the first detection of linearly polarized emission at an observing wavelength of 350 mu m from the radioloud active galactic nucleus 3C 279. We conducted polarization observations for 3C 279 using the SHARP polarimeter in the Caltech Submillimeter Observatory on 2014 March 13 and 14. For the first time, we detected the linear polarization with the degree of polarization of 13.3% +/- 3.4% (3.9s) and the electric vector position angle (EVPA) of 34. 7 +/- 5. 6. We also observed 3C 279 simultaneously at 13, 7, and 3.5 mm in dual polarization with the Korean very long baseline interferometry (VLBI) Network on 2014 March 6 (single dish) and imaged in milliarcsecond (mas) scales at 13, 7, 3.5, and 2.3 mm on March 22 (VLBI). We found that the degree of linear polarization increases from 10% to 13% at 13 mm to 350 mu m and the EVPAs at all observing frequencies are parallel within <10 degrees to the direction of the jet at mas scale, implying that the integrated magnetic fields are perpendicular to the jet in the innermost regions. We also found that the Faraday rotation measures RM are in a range of -6.5 x 10(2) similar to -2.7 x 10(3) rad m(-2) between 13 and 3.5 mm, and are scaled as a function of wavelength: |RM| alpha lambda(-2.2). These results indicate that the millimeter and sub-millimeter polarization emission are generated in the compact jet within 1 mas scale and affected by a Faraday screen in or in the close proximity of the jet.