Magnetic Field Structure in Spheroidal Star-forming Clouds

Authors

Philip C. Myers, Harvard-Smithsonian Center for Astrophysics
Shantanu Basu, The University of Western OntarioFollow
Sayantan Auddy, Harvard-Smithsonian Center for Astrophysics

Document Type

Article

Publication Date

11-20-2018

Journal

Astrophysical Journal

Volume

868

Issue

1

URL with Digital Object Identifier

10.3847/1538-4357/aae695

Abstract

A model of magnetic field structure is presented to help test the prevalence of flux freezing in star-forming clouds of various shapes, orientations, and degrees of central concentration, and to estimate their magnetic field strength. The model is based on weak-field flux freezing in centrally condensed Plummer spheres and spheroids of oblate and prolate shape. For a spheroid of given density contrast, aspect ratio, and inclination, the model estimates the local field strength and direction, and the global field pattern of hourglass shape. Comparisons with a polarization simulation indicate typical angle agreement within 1°-10°. Scalable analytic expressions are given to match observed polarization patterns and to provide inputs to radiative transfer codes for more accurate predictions. The model may apply to polarization observations of dense cores, elongated filamentary clouds, and magnetized circumstellar disks.