Methanol Masers as tools for investigating the magnetic field inmassive star-forming regions.
The term maser is the acronym of microwave amplification by stimulated emission of radiation. An astronomical maser is a naturally occuring source of stimulated emission. These astronomical sources have an important role in the modern astrophysics. In fact they are useful tools in several scenarios both in the Galaxy and in other galaxies (e.g. early stages of star formation, motion of the Local Group). During my talk I will show how one of the maser species (methanol) is becoming an important tool for investigating the magnetic field in massive star-forming regions. In fact, the role of magnetic fields during the protostellar phase of high-mass star-formation is a debated topic. In particular, it is still unclear how magnetic fields influence the formation and the dynamics of disks and outflows. I will present our recent results where we were able to investigate the magnetic field at mas resolution in the massive star-forming region W75N (Surcis et al. 2009) and to observe the 3-dimensional magnetic field structure around the disk of the massive star Cepheus A (Vlemmings et al., in press), in both cases by studying the polarization emissions of the 6.7 GHz methanol masers arising in those regions.