Coffee talks
Friday 21/01/2022 @ 11:30, On-line - meet.google.com/sue-bwvk-axf
Daria Dall'Olio (Onsala observatory), "Magnetic fields inside out: deciphering the magnetic field role in the formation of young stars"
Magnetic fields are believed to play a crucial role during the formation and early evolution of stars, hindering the fragmentation and the collapse of the parental cloud, and affecting the accretion mechanisms and feedback phenomena. However, several questions still need to be addressed to clarify the importance of magnetic fields, such as how strong they are, at what evolutionary stage and spatial scales their action becomes relevant. Furthermore, the magnetic field parameters are still poorly constrained especially at small scales, i.e. few astronomical units from the central object, where the accretion disc and the base of the outflow are located. Thus we need to probe magnetic fields at different scales, at different evolutionary steps and possibly with different tracers. In this talk, I will present our recent results I will show and that the magnetic field morphology around high-mass protostars can be successfully traced at different scales by using a multi-wavelength and multi-scale approach observing masers, dust and thermal lines. Astronomical masers have been effective tools to study magnetic fields for many years. By measuring linear polarization angles and Zeeman splitting of different maser species it is possible to obtain magnetic field morphology and strength with au-scale detail. Polarized emission of dust has been also extensively used to probe the magnetic field properties at mpc or larger scale, applying the Davis-Chandrasekhar-Fermi method or the Structure Function. In addition to maser and dust observations, thanks to the current capabilities of ALMA, magnetic field properties can be inferred also by detecting thermal line polarization, known as Goldreich-Kylafis effect.