A quantum-chemical study to the magnetic characteristics of methanol and its applications in astronomy

Licentiatavhandling, 2018

Magnetic fields play an important role during star formation. Direct magnetic field strength observations have proven specifically challenging in the dynamic protostellar phase. Because of their occurrence in the densest parts of star forming regions, masers, through polarization observations, are the main source of magnetic field strength and morphology measurements around protostars. Of all maser species, methanol is one of the strongest and most abundant tracers of gas around high-mass protostellar disks and in outflows. However, because experimental determination of the magnetic character- istics of methanol has remained unsuccessful, a magnetic field strength analysis of these regions could hitherto not be performed. In this thesis, we present quantum-chemical calculations of the magnetic characteristics of methanol. We present the parameters characterizing the internal magnetic interactions: the hyperfine structure, as well as the parameters characterizing the interaction of methanol with an external magnetic field. We use these parameters in re-analyzing methanol maser polarization observa- tions. With these calculations, we can confirm the presence of dynamically important magnetic fields around protostars.