VLBA SiO maser observations of the OH/IR star OH 44.8-2.3: magnetic field and morphology
Paper i proceeding, 2012

We report on Very Long Baseline Array SiO maser observations of the OH/IR star OH 44.8 - 2.3. The observations show that the maser features form a ring located at a distance of 5.4 AU around the central star. The masers show high fractional linear polarization up to 100%. The polarization vectors are consistent with a dipole field morphology. Additionally, we report a tentative detection of circular polarization of 7% for the brightest maser feature. This indicates a magnetic field of 1.5 ± 0.3 G. The SiO masers and the 1612 MHz OH masers suggest a mildly preferred outflow direction in the circumstellar environment of this star. The observed polarization is consistent with magnetic field structures along the preferred outflow direction. This could indicate the possible role of the magnetic fields in shaping the circumstellar environment of this object.

Polarization

Magnetic Fields

Stars

Maser

Författare

N. Amiri

Universiteit Leiden

Wouter Vlemmings

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

A. Kemball

Joint Institute for VLBI in Europe (JIVE)

H. J. van Langevelde

University of Illinois

Proceedings of the International Astronomical Union

1743-9213 (ISSN) 1743-9221 (eISSN)

Vol. 8 5287 54-58

The XXVIIIth General Assembly of the International Astronomical Union (IAU
Beijing, China,

Ämneskategorier

Astronomi, astrofysik och kosmologi

Fundament

Grundläggande vetenskaper

DOI

10.1017/S1743921312006631

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Senast uppdaterat

2021-02-18