The galactic magnetic field in the quasar 3C216
Abstract
Multifrequency polarimetric observations made with the Very Long Baseline Array of the quasar 3C216 reveal the presence of Faraday rotation measures (RMs) in excess of 2000 rad/m**2 in the source rest frame, in the arc of emission located at ~ 140 mas from the core. Rotation measures in the range -300 - +300 rad/m**2 are detected in the inner 5 mas (~30 parsecs). while the rotation measures near the core can be explained as due to a magnetic field in the narrow line region, we favor the interpretation for the high RM in the arc as due to a ``local'' Faraday screen, produced in a shock where the jet is deflected by the interstellar medium of the host galaxy. Our results indicate that a galacit magnetic field of the order of 50 microGauss on a scale greater than 100 pc must be present in the galactic medium.
Keywords
Cite
@article{arxiv.astro-ph/9907321,
title = {The galactic magnetic field in the quasar 3C216},
author = {T. Venturi and G. B. Taylor},
journal= {arXiv preprint arXiv:astro-ph/9907321},
year = {2009}
}
Comments
23 pages, 3 tables, 11 figures. To appear on The Astronomical Journal, November 1999 Issue