EDP Sciences
Free access
Volume 480, Number 3, March IV 2008
Page(s) 767 - 773
Section Interstellar and circumstellar matter
DOI http://dx.doi.org/10.1051/0004-6361:20078670
Published online 17 January 2008

A&A 480, 767-773 (2008)
DOI: 10.1051/0004-6361:20078670

First VLBI observations of methanol maser polarisation, in G339.88-1.26

R. Dodson

Observatorio Astronómico Nacional, Apartado 112, Alcala de Henares 28803, Spain
    e-mail: r.dodson@oan.es

(Received 14 September 2007 / Accepted 21 December 2007)

Aims.We investigate class II methanol masers and the environment in which they form with the Long Baseline Array (LBA).
Methods.Using full polarisation VLBI, we were able to measure the magnetic field directions so as to distinguish between the two main models of the environment in which methanol masers form: disks or shocks.
Results.We present polarised images of the methanol maser source G339.88-1.26, made with the LBA at 6.7-GHz. With these first polarisation maps made with the LBA, which successfully reproduce observations with the ATCA confirming the new AIPS code, a new technique for Southern VLBI is opened. The magnetic field directions found are inconstant with methanol masers arising in disks for the majority of the emission.

Key words: techniques: polarimetric -- masers -- radio lines: stars -- stars: formation -- stars: individual: G339.88-1.26

© ESO 2008