A Sino-German 6 cm polarization survey of the Galactic plane II. The region from 129 degree to 230 degree longitude

TL;DR

This paper presents a detailed 6 cm polarization survey of the Galactic plane, revealing insights into the Galactic magnetic field and interstellar medium by combining sensitive radio observations with WMAP data.

Contribution

It introduces a new high-resolution polarization survey at 6 cm of the Galactic plane from 129° to 230° longitude, enhancing understanding of magnetic structures and Faraday screens.

Findings

Detection of extended Faraday Screens with large rotation measures

Provision of new magnetic field information in the Galactic plane

Complementary data for discrete Galactic objects

Abstract

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. We aim to survey the Galactic plane at 6 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. The Urumqi 25-m telescope is used for a sensitive 6 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. Total intensity and polarization maps are presented for a Galactic plane region of 129 degree < l < 230 degree and |b| < 5 degree in the anti-centre with an angular resolution of 9'5 and an average sensitivity of 0.6 mK and 0.4 mK Tb in total and polarized intensity, respectively. We briefly discuss the properties of some extended Faraday Screens detected in the 6 cm polarization maps. The Sino-German 6 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.