Properties of the warm magnetized ISM, as inferred from WSRT polarimetric imaging

Abstract

We describe a first attempt to derive properties of the regular and turbulent Galactic magnetic field from multi-frequency polarimetric observations of the diffuse Galactic synchrotron background. A single-cell-size model of the thin Galactic disk is constructed which includes random and regular magnetic fields and thermal and relativistic electrons. The disk is irradiated from behind with a uniform partially polarized background. Radiation from the background and from the thin disk is Faraday rotated and depolarized while propagating through the medium. The model parameters are estimated from a comparison with 350 MHz observations in two regions at intermediate latitudes done with the Westerbork Synthesis Radio Telescope. We obtain good consistency between the estimates for the random and regular magnetic field strengths and typical scales of structure in the two regions. The regular magnetic field strength found is a few microGauss, and the ratio of random to regular magnetic field strength is 0.7 +/- 0.5, for a typical scale of the random component of 15 +/- 10 pc. Furthermore, the regular magnetic field is directed almost perpendicular to the line of sight. This modeling is a potentially powerful method to estimate the structure of the Galactic magnetic field, especially when more polarimetric observations of the diffuse synchrotron background at intermediate latitudes become available.

arXiv comment12 pages, 6 figures, accepted by A&A

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Cited by in corpus (17)

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• Low-frequency Faraday rotation measures towards pulsars using LOFAR: probing the 3-D Galactic halo magnetic field
• A 189 MHz, 2400 square degree polarization survey with the Murchison Widefield Array 32-element prototype
• Magnetic Fields in the Milky Way
• WSRT Faraday tomography of the Galactic ISM at λ~ 0.86 m
• Structure in the polarized Galactic synchrotron emission, in particular `depolarization canals'
• Galactic interstellar turbulence in the southern sky seen through spatial gradients of the polarization vector
• Turbulent axion-photon conversions in the Milky-Way
• Cosmic Magnetism in Centimeter and Meter Wavelength Radio Astronomy
• Properties of the warm magnetized ISM, as inferred from WSRT polarimetric imaging
• Properties of Turbulence in the Very Local Interstellar Clouds
• The WENSS and Dwingeloo surveys and the Galactic magnetic field
• Probing the Magnetized Interstellar Medium Surrounding the Planetary Nebula Sh 2-216
• Magnetic Field and Faraday Rotation Measure in the Turbulent Warm Ionized Medium
• A Comparison of Multi-Phase Magnetic Field Tracers in a High-Galactic Latitude Region of the Filamentary Interstellar Medium
• Magnetic fields in the Southern Galactic Plane Survey
• High Sensitivity Methodologies to Detect Radio Band Gravitational Waves