A Survey of the Polarized Emission from the Galactic Plane at 1420 MHz
  with Arcminute Angular Resolution
  Context: Observations of polarized emission are a significant source of
information on the magnetic field that pervades the Interstellar Medium of the
Galaxy. Despite the acknowledged importance of the magnetic field in
interstellar processes, our knowledge of field configurations on all scales is
seriously limited. Aims: This paper describes an extensive survey of polarized
Galactic emission at 1.4 GHz that provides data with arcminute resolution and
complete coverage of all structures from the broadest angular scales to the
resolution limit, giving information on the magneto-ionic medium over a wide
range of interstellar environments. Methods: Data from the DRAO Synthesis
Telescope, the Effelsberg 100-m Telescope, and the DRAO 26-m Telescope have
been combined. Angular resolution is ~1' and the survey extends from l = 66 deg
to l = 175 deg over a range -3 deg < b < 5 deg along the northern Galactic
plane, with a high-latitude extension from l = 101 deg to l = 116 deg up to b =
17.5 deg. This is the first extensive polarization survey to present
aperture-synthesis data combined with data from single antennas, and the
techniques developed to achieve this combination are described. Results: The
appearance of the extended polarized emission at 1.4 GHz is dominated by
Faraday rotation along the propagation path, and the diffuse polarized sky
bears little resemblance to the total-intensity sky. There is extensive
depolarization, arising from vector averaging on long lines of sight, from HII
regions, and from diffuse ionized gas seen in H-alpha images. Preliminary
interpretation is presented of selected polarization features on scales from
parsecs (the planetary nebula Sh 2-216) to hundreds of parsecs (a supperbubble
GSH 166-01-17) to kiloparsecs (polarized emission in the direction of Cygnus
X).
