1. Determining the Magnetic Field in the Galactic Plane from New Arecibo Pulsar Faraday Rotation Measurements
- Author
-
Curtin, Alice P., Weisberg, Joel M., and Rankin, Joanna M.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We develop a new method for studying the Galactic magnetic field along the spiral arms using pulsar Faraday rotation measures (RMs). Our new technique accounts for the dot-product nature of Faraday rotation and also splits the associated path integral into segments corresponding to particular zones along the LOS. We apply this geometrically-corrected, arm-by-arm technique to the low-latitude portion of a recently published set of Arecibo Faraday RMs for 313 pulsars along with previously obtained RMs in the same regions. We find disparities $>1\sigma$ between the magnitude of the field above and below the plane in the Local Arm, Sagittarius Arm, Sagittarius-to-Scutum Interarm, the Scutum Arm, and Perseus Arm. We find evidence for a single field reversal near the Local/Sagittarius arm boundary. Interestingly, our results suggest that this field reversal is dependent on latitude, occurring inside the Sagittarius arm at negative Galactic latitudes and at the Local-to-Sagittarius Arm boundary at positive Galactic latitudes. We discuss all of our results in the context of different models and other observational Galactic magnetic field analyses., Comment: Accepted in ApJ
- Published
- 2024