Magnetic field measurements at milliarcsecond resolution around massive young stellar objects

TL;DR

This study uses milliarcsecond resolution measurements of polarized CH3OH maser emission to investigate magnetic fields near massive young stellar objects, revealing their alignment with molecular outflows and aiding star formation models.

Contribution

It provides new high-resolution magnetic field measurements around massive YSOs and explores the estimation of magnetic field strength via Zeeman-splitting of methanol masers.

Findings

Magnetic fields are primarily aligned with molecular outflows.

Detection of polarized maser emission towards 10 massive YSOs.

Ongoing campaign to increase the statistical sample.

Abstract

Magnetic fields have only recently been included in theoretical simulations of high-mass star formation. The simulations show that magnetic fields can play a crucial role not only in the formation and dynamics of molecular outflows, but also in the evolution of circumstellar disks. Therefore, new measurements of magnetic fields at milliarcsecond resolution close to massive young stellar objects (YSOs) are fundamental for providing new input for numerical simulations and for understanding the formation process of massive stars. The polarized emission of 6.7 GHz CH3OH masers allows us to investigate the magnetic field close to the massive YSO where the outflows and disks are formed. Recently, we have detected with the EVN CH3OH maser polarized emission towards 10 massive YSOs. From a first statistical analysis we have found evidence that magnetic fields are primarily oriented along the molecular outflows. To improve our statistics we are carrying on a large observational EVN campaign for a total of 19 sources, the preliminary results of the first seven sources are presented in this contribution. Furthermore, we also describe our efforts to estimate the Lande' g-factors of the CH3OH maser transition to determine the magnetic field strength from our Zeeman-splitting measurements.