Quantum-Chemical calculations revealing the effects of magnetic fields on methanol masers
Date Issued
2018
Author(s)
Lankhaar, Boy
•
Vlemmings, Wouter
•
•
van Langevelde, Huib Jan
•
Groenenboom, Gerrit C.
•
van der Avoird, Ad
Abstract
Maser observations of both linearly and circularly polarized emission have provided unique information on the magnetic field in the densest parts of star forming regions, where non-maser magnetic field tracers are scarce. While linear polarization observations provide morphological constraints, magnetic field strengths are determined by measuring the Zeeman splitting in circularly polarized emission. Methanol is of special interest as it is one of the most abundant maser species and its different transitions probe unique areas around the protostar. However, its precise Zeeman-parameters are unknown. Experimental efforts to determine these Zeeman-parameters have failed. Here we present quantum-chemical calculations of the Zeeman-parameters of methanol, along with calculations of the hyperfine structure that are necessary to interpret the Zeeman effect in methanol. We use this model in re-analyzing methanol maser polarization observations. We discuss different mechanisms for hyperfine-state preference in the pumping of torsion-rotation transitions involved in the maser-action.
Coverage
Astrophysical Masers: Unlocking the Mysteries of the Universe
All editors
Tarchi, Andrea; Reid, Mark J.; Castangia, Paola
Volume
vol. 13, S336
Start page
23
Conferenece
IAUS 336: Astrophysical Masers: Unlocking the Mysteries of the Universe
Conferenece place
Cagliari, Italia
Conferenece date
4-8 Settembre, 2017
Issn Identifier
1743-9213
Ads BibCode
2018IAUS..336...23L
Rights
open.access
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