Confirmation of a Faraday Rotation Measure Anomaly in Cygnus

Abstract

We confirm the reality of a reversal of the sign of the Faraday Rotation Measure in the Galactic plane in Cygnus (Lazio et al, 1990), possibly associated with the Cygnus OB1 association. The rotation measure changes by several hundred rad/m${}^2$ over an angular scale of $2-5^{\circ }$. We show that a simple model of an expanding plasma shell with an enhanced density and magnetic field, consistent with observations of H$\alpha$ emission in this part of sky, and physically associated with a superbubble of the Cygnus OB1 association, can account for the magnitude and angular scale of this feature.

arXiv commentSubmitted to the Astrophysical Journal

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Cited by in corpus (9)

• Magnetic Fields in Large Diameter HII Regions Revealed by the Faraday Rotation of Compact Extragalactic Radio Sources
• Structure in the Rotation Measure Sky
• A radio-polarisation and rotation measure study of the Gum Nebula and its environment
• Plasma Diagnostics of the Interstellar Medium with Radio Astronomy
• Planck intermediate results. XXXIV. The magnetic field structure in the Rosette Nebula
• A Faraday Rotation Study of the Stellar Bubble and HII Region Associated with the W4 Complex
• Denser Sampling of the Rosette Nebula with Faraday Rotation Measurements: Improved Estimates of Magnetic Fields in HII Regions
• Probing the Rosette Nebula Stellar Bubble with Faraday Rotation
• Turbulent magnetic field in the HII region Sh 2-27