OH maser toward IRAS 06056+2131: polarization parameters and evolution status

TL;DR

This study uses high-resolution radio interferometry to analyze OH maser emission in a star-forming region, revealing magnetic field properties and polarization characteristics that inform the evolutionary status of the embedded protostar.

Contribution

First high-resolution polarization observations of OH masers in IRAS 06056+2131, revealing magnetic field strength and orientation related to star formation processes.

Findings

Detected 1665 MHz OH maser emission with ~4 Jy intensity.

Identified a Zeeman pair indicating a magnetic field of ~-1.5 mG.

Found polarization vectors aligned with the outflow orientation.

Abstract

We present high angular resolution observations of OH maser emission towards the high-mass star forming region IRAS 06056+2131. The observations were carried out using the UK radio interferometer array, Multi-Element Radio Linked Interferometer Network (MERLIN) in the OH main lines at 1665- and 1667-MHz, in addition to the OH satellite line at 1720-MHz. The results of this study revealed emission in the 1665 MHz line with an estimated total intensity of $\sim 4$ Jy. We did not detect any emission from the 1667-MHz and 1720-MHz lines. The full polarization mode of MERLIN enables us to investigate the magnetic field in the OH maser region. Our results show that IRAS 06056+2131 is a highly circularly polarized source. In this transition, a Zeeman pair is identified from which a magnetic strength of $\sim -1.5$ mG is inferred. The orientation of the linear polarization vectors suggests that the magnetic field lines at the location of the OH maser emission \textbf{might be} in agreement with the orientation of the outflow thought to be associated with this source. The star forming evolutionary status of the embedded proto-stellar object is discussed.