eCite Digital Repository

A radio and optical polarization study of the magnetic field in the Small Magellanic Cloud


Mao, SA and Gaensler, BM and Stanimirovic, S and Haverkorn, M and McClure-Griffiths, NM and Staveley-Smith, L and Dickey, JM, A radio and optical polarization study of the magnetic field in the Small Magellanic Cloud, The Astrophysical Journal, 688, (2) pp. 1029-1049. ISSN 0004-637X (2008) [Refereed Article]


PDF (Erratum)

Copyright Statement

Copyright 2008 American Astronomical Society

DOI: doi:10.1086/590546


We present a study of the magnetic field of the Small Magellanic Cloud (SMC), carried out using radio Faraday rotation and optical starlight polarization data. Consistent negative rotation measures (RMs) across the SMC indicate that the line-of-sight magnetic field is directed uniformly away from us with a strength 0.19 0.06 G. Applying the Chandrasekhar-Fermi method to starlight polarization data yields an ordered magnetic field in the plane of the sky of strength 1.6 0.4 G oriented at a position angle 4 12, measured counterclockwise from the great circle on the sky joining the SMC to the Large Magellanic Cloud (LMC). We construct a three-dimensional magnetic field model of the SMC, under the assumption that the RMs and starlight polarization probe the same underlying large-scale field. The vector defining the overall orientation of the SMC magnetic field shows a potential alignment with the vector joining the center of the SMC to the center of the LMC, suggesting the possibility of a "pan-Magellanic" magnetic field. A cosmic-ray-driven dynamo is the most viable explanation of the observed field geometry, but has difficulties accounting for the observed unidirectional field lines. A study of Faraday rotation through the Magellanic Bridge is needed to further test the pan-Magellanic field hypothesis.

Item Details

Item Type:Refereed Article
Keywords:magnetic fields; polarization; Magellanic Clouds
Research Division:Physical Sciences
Research Group:Astronomical sciences
Research Field:Solar physics
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the physical sciences
UTAS Author:Dickey, JM (Professor John Dickey)
ID Code:53935
Year Published:2008
Web of Science® Times Cited:68
Deposited By:Physics
Deposited On:2009-01-28
Last Modified:2017-08-22
Downloads:176 View Download Statistics

Repository Staff Only: item control page