Polarisation of Class II Methanol Masers

P. D. Stack, S. P. Ellingsen
2011 Publications Astronomical Society of Australia  
AbstractWe have used the University of Tasmania Mt Pleasant 26-m radio telescope to investigate the polarisation characteristics of a sample of strong 6.7 GHz methanol masers, the first spectral line polarisation observations to be undertaken with this instrument. As part of this process we have developed a new technique for calibrating linear polarisation spectral line observations. This calibration method gives results consistent with more traditional techniques, but requires much less
more » ... ng time on the telescope. We have made the first polarisation measurements of a number of 6.7 GHz methanol masers and find linear polarisation at levels from a few to 10% in most of the sources we observed, consistent with previous results. We also investigated the circular polarisation produced by Zeeman splitting in the 6.7 GHz methanol maser G9.62+0.20 to get an estimate of the line of sight magnetic field strength of 35±7 mG.
doi:10.1071/as11029 fatcat:57du3pa225hwpov6vilrrp4yhu