Characterization of methanol as a magnetic field tracer in star-forming regions
Artikel i vetenskaplig tidskrift, 2018

Magnetic fields play an important role during star formation1. Direct magnetic field strength observations have proven particularly challenging in the extremely dynamic protostellar phase2,3,4. 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 protostars2. 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, as experimental determination of the magnetic characteristics of methanol has remained largely unsuccessful5, a robust magnetic field strength analysis of these regions could hitherto not be performed. Here, we report a quantitative theoretical model of the magnetic properties of methanol, including the complicated hyperfine structure that results from its internal rotation6. We show that the large range in values of the Landé g factors of the hyperfine components of each maser line lead to conclusions that differ substantially from the current interpretation based on a single effective g factor. These conclusions are more consistent with other observations7,8 and confirm the presence of dynamically important magnetic fields around protostars. Additionally, our calculations show that (nonlinear) Zeeman effects must be taken into account to further enhance the accuracy of cosmological electron-to-proton mass ratio determinations using methanol9,10,11,12.

star-formation

Zeeman effect

masers

methanol

maser polarization

Författare

Boy Lankhaar

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik, Galaktisk astrofysik

Wouter Vlemmings

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik, Galaktisk astrofysik

G. Surcis

Organisation okänd

H.J. van Langevelde

Organisation okänd

Gerrit C. Groenenboom

Organisation okänd

Ad van der Avoird

Organisation okänd

Nature Astronomy

2397-3366 (ISSN) 2397-3366 (eISSN)

Vol. 2 145-150

Fundamental fysik, magnetfält och gravitation, med nya och framtida radio interferometrar

Vetenskapsrådet (VR), 2014-01-01 -- 2019-12-31.

Magnetic fields and the outflows during the formation and evolution of stars (OUTFLOWMAGN)

Europeiska kommissionen (FP7), 2014-05-01 -- 2019-04-30.

Ämneskategorier

Astronomi, astrofysik och kosmologi

Fundament

Grundläggande vetenskaper

Infrastruktur

Onsala rymdobservatorium

DOI

10.1038/s41550-017-0341-8

Mer information

Senast uppdaterat

2018-10-05