- evn2024@mpifr.de
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Contribution
Preliminary results of identifying the g-factor of 6.7 GHz methanol maser via polarization observations
Speakers
- Ms. Agnieszka KOBAK
Primary authors
- Ms. Agnieszka KOBAK (Nicolaus Copernicus Univeristy)
Co-authors
- Dr. Gabriele SURCIS (INAF - Osservatorio Astronomico di Cagliari)
- Prof. Anna BARTKIEWICZ (Torun Institute of Astronomy, NCU)
- Prof. Marian SZYMCZAK (Torun Institute of Astronomy, NCU)
- Prof. Wouter VLEMMINGS (Chalmers University of Technology)
Content
Cosmic masers enable us to estimate the magnetic field via the Zeeman effect, especially in high-mass star-forming regions where OH and methanol masers occur. We can measure the Zeeman-splitting of the maser lines and, knowing the Landé g-factor, determine the strength of the magnetic field. The g-factor is undoubtedly known for the excited OH maser, but for methanol masers, it is still under investigation because it is still unclear which of the eight hyperfine transitions (each with its own g-factor) dominates the 6.7 GHz maser emission. To resolve this issue, we conducted simultaneous observations of the 6.035 GHz exited OH and of the 6.7 GHz methanol maser emissions for two bright sources, for which maser emissions arise in the same spatio-kinematical regions and have clear Zeeman-splittings. Simultaneous observations of both maser lines allow us to compare the magnetic field estimated with the ex-OH masers with the Zeeman-splitting measured in the methanol maser line and to figure out the dominant hyperfine transition of the 6.7 GHz methanol maser. We will present preliminary results from the project EK052 (E22C002), which was observed in May 2023.