Open AccessParsec‐scale polarization of the jet in quasar 4C 71.07
Author(s) -
Hutchison J. M.,
Cawthorne T. V.,
Gabuzda D. C.
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.04097.x
Subject(s) - physics , faraday effect , astrophysics , quasar , position angle , polarization (electrochemistry) , very long baseline interferometry , very long baseline array , brightness , magnetic field , rotation (mathematics) , jet (fluid) , astronomy , galaxy , geometry , chemistry , quantum mechanics , mathematics , thermodynamics
Very long‐baseline interferometry (VLBI) observations of the quasar 4C 71.07 (0836+710) at frequencies of 5 and 8.4 GHz at two epochs are used to investigate apparent misalignments between the magnetic field and jet direction found in this source. The observed polarization angles are not consistent with Faraday rotation of synchrotron radiation from an aligned magnetic field. Internal Faraday rotation in a uniform spherical source is also ruled out by the observations, and while the misalignments could result from internal Faraday rotation in a non‐uniform source, no strong signatures of this effect were found. The jet shows two distinct kinks at which the ridge‐line changes direction and then reverts to its original direction. The magnetic field in these regions is parallel to the jet, and remains so as the jet bends. It seems likely that the largest remaining misalignment is associated with another such kink that is unresolved by these observations. The percentage polarization decreases near the bright knots, consistent with enhancement in brightness by compressions in the plane normal to the jet axis. The inferred rotation measure is low (100 rad m −2 ) throughout the jet, as for other quasars. However near the core, the polarization position angles suggest a rotation measure that appears to be uncharacteristically low by comparison with other quasars.