A quantum mechanical approach to establishing the magnetic field orientation from a maser Zeeman profile
arXiv:1404.5816 · doi:10.1093/mnras/stu429
Abstract
Recent comparisons of magnetic field directions derived from maser Zeeman splitting with those derived from continuum source rotation measures have prompted new analysis of the propagation of the Zeeman split components, and the inferred field orientation. In order to do this, we first review differing electric field polarization conventions used in past studies. With these clearly and consistently defined, we then show that for a given Zeeman splitting spectrum, the magnetic field direction is fully determined and predictable on theoretical grounds: when a magnetic field is oriented away from the observer, the left-hand circular polarization is observed at higher frequency and the right-hand polarization at lower frequency. This is consistent with classical Lorentzian derivations. The consequent interpretation of recent measurements then raises the possibility of a reversal between the large-scale field (traced by rotation measures) and the small-scale field (traced by maser Zeeman splitting).
arXiv comment10 pages, 5 Figures, accepted for publication in MNRAS
References in corpus (8)
- Rotation Measures of Extragalactic Sources Behind the Southern Galactic Plane: New Insights into the Large-Scale Magnetic Field of the Inner Milky Way
- Modeling the Magnetic Field in the Galactic Disk using New Rotation Measure Observations from the Very Large Array
- Full-Polarization Observations of OH Masers in Massive Star-Forming Regions: I. Data
- Interstellar Hydroxyl Masers in the Galaxy. II. Zeeman Pairs and the Galactic Magnetic Field
- The structure of the magnetic field in the massive star-forming region W75N
- The Galactic distribution of magnetic fields in molecular clouds and HII regions
- MAGMO: Coherent magnetic fields in the star forming regions of the Carina-Sagittarius spiral arm tangent
- On the theory of astronomical maser. II. Polarization of maser radiation