The generation and transformation of polarization signals in molecular lines through collective anisotropic resonant scattering
Journal article, 2022

We discuss the existence of elliptical polarization in rotational spectral lines of CO and other molecules within the context of the Anisotropic Resonant Scattering (ARS) model. We show that the effect of ARS on the radiation field can lead to not only the previously predicted transformation of background linear polarization into circular polarization (i.e. Faraday conversion) but also the occurrence of Faraday rotation and the generation of elliptically polarized signals in an otherwise initially unpolarized radiation field. This is due to a collective behaviour between the large number of molecules acting as a diffraction ensemble that strongly favours forward scattering over any other mode. Our application to astronomical data demonstrates the dependency of the Stokes parameters on the strength and orientation of the ambient magnetic field, and suggests that ARS will manifest itself for a wide range of molecular species and transitions.

ISM: molecules

ISM: clouds

ISM: magnetic fields

Author

M. Houde

Western University

Boy Lankhaar

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

F. Rajabi

Western University

Perimeter Institute for Theoretical Physics

M. A. Chamma

Western University

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 511 1 295-315

Subject Categories

Atom and Molecular Physics and Optics

Other Physics Topics

Condensed Matter Physics

DOI

10.1093/mnras/stab3806

More information

Latest update

4/20/2022