A Sino-German λ6 cm polarization survey of the Galactic plane. II. The region from 129° to 230° longitude

Context. Linearly polarized Galactic synchrotron emission provides valuable information about the properties of the Galactic magnetic field and the interstellar magneto-ionic medium, when Faraday rotation along the line of sight is properly taken into account.
Aims: We aim to survey the Galactic plane at λ6 cm including linear polarization. At such a short wavelength Faraday rotation effects are in general small and the Galactic magnetic field properties can be probed to larger distances than at long wavelengths.
Methods: The Urumqi 25-m telescope is used for a sensitive λ6 cm survey in total and polarized intensities. WMAP K-band (22.8 GHz) polarization data are used to restore the absolute zero-level of the Urumqi U and Q maps by extrapolation.
Results: Total intensity and polarization maps are presented for a Galactic plane region of 129° ≤ ℓ ≤ 230° and |b| ≤ 5° in the anti-centre with an angular resolution of 9.5 arcmin and an average sensitivity of 0.6 mK and 0.4 mK T_B in total and polarized intensity, respectively. We briefly discuss the properties of some extended Faraday Screens detected in the λ6 cm polarization maps.
Conclusions: The Sino-German λ6 cm polarization survey provides new information about the properties of the magnetic ISM. The survey also adds valuable information for discrete Galactic objects and is in particular suited to detect extended Faraday Screens with large rotation measures hosting strong regular magnetic fields.