Probing the Parsec-scale Accretion Flow of 3C 84 with Millimeter Wavelength Polarimetry

Citation:

R. L. Plambeck, G. C. Bower, Ramprasad Rao, D. P. Marrone, S. G. Jorstad, A. P. Marscher, S. S. Doeleman, V. L. Fish, and M. D. Johnson. 2014. “Probing the Parsec-scale Accretion Flow of 3C 84 with Millimeter Wavelength Polarimetry.” The Astrophysical Journal, 797.

Abstract:

We report the discovery of Faraday rotation toward radio source 3C 84,the active galactic nucleus in NGC 1275 at the core of the PerseusCluster. The rotation measure (RM), determined from polarizationobservations at wavelengths of 1.3 and 0.9 mm, is (8.7 ±2.3)× 105 rad m-2, among the largest evermeasured. The RM remained relatively constant over a 2 yr period even asthe intrinsic polarization position angle wrapped through a span of300°. The Faraday rotation is likely to originate either in theboundary layer of the radio jet from the nucleus or in the accretionflow onto the central black hole. The accretion flow probably isdisk-like rather than spherical on scales of less than a parsec,otherwise the RM would be even larger.