Linear Polarization of Class I Methanol Masers in Massive Star-forming Regions
Journal article, 2016

Class I methanol masers are found to be good tracers of the interaction between outflows from massive young stellar objects with their surrounding media. Although polarization observations of Class II methanol masers have been able to provide information about magnetic fields close to the central (proto)stars, polarization observations of Class I methanol masers are rare, especially at 44 and 95 GHz. We present the results of linear polarization observations of 39 Class I methanol maser sources at 44 and 95 GHz. These two lines are observed simultaneously with one of the 21 m Korean VLBI Network telescopes in single-dish mode. Approximately 60% of the observed sources have fractional polarizations of a few percent in at least one transition. This is the first reported detection of linear polarization of the 44 GHz methanol maser. The two maser transitions show similar polarization properties, indicating that they trace similar magnetic environments, although the fraction of the linear polarization is slightly higher at 95 GHz. We discuss the association between the directions of polarization angles and outflows. We also discuss some targets having different polarization properties at both lines, including DR21(OH) and G82.58+0.20, which show the 90° polarization angle flip at 44 GHz.

polarization

stars: massive

ISM: magnetic fields

stars: protostars

surveys

masers

Author

Ji-hyun Kang

Korea Astronomy and Space Science Institute

Do-Young Byun

Korea Astronomy and Space Science Institute

Kee-Tae Kim

Korea Astronomy and Space Science Institute

Jongsoo Kim

Korea Astronomy and Space Science Institute

A. Lyo

Korea Astronomy and Space Science Institute

Wouter Vlemmings

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

Astrophysical Journal, Supplement Series

0067-0049 (ISSN) 1538-4365 (eISSN)

Vol. 227 2 17

Magnetic fields and the outflows during the formation and evolution of stars (OUTFLOWMAGN)

European Commission (EC) (EC/FP7/614264), 2014-05-01 -- 2019-04-30.

Subject Categories

Astronomy, Astrophysics and Cosmology

Roots

Basic sciences

Infrastructure

Onsala Space Observatory

DOI

10.3847/0067-0049/227/2/17

More information

Latest update

6/14/2018