Large Magnetic Fields and Motions of OH Masers in W75 N
arXiv:astro-ph/0611097 · doi:10.1086/510578
Abstract
We report on a second epoch of VLBA observations of the 1665 and 1667 MHz OH masers in the massive star-forming region W75 N. We find evidence to confirm the existence of very strong (~40 mG) magnetic fields near source VLA 2. The masers near VLA 2 are dynamically distinct and include a very bright spot apparently moving at 50 km/s relative to those around VLA 1. This fast-moving spot may be an example of a rare class of OH masers seen in outflows in star-forming regions. Due to the variability of these masers and the rapidity of their motions, tracking these motions will require multiple observations over a significantly shorter time baseline than obtained here. Proper motions of the masers near VLA 1 are more suggestive of streaming along magnetized shocks rather than Keplerian rotation in a disk. The motions of the easternmost cluster of masers in W75 N (B) may be tracing slow expansion around an unseen exciting source.
arXiv comment7 pages including 4 figures (2 color) & 3 tables, to appear in ApJ
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- Proper Motions of OH Masers and Magnetic Fields in Massive Star-Forming Regions
- Linear polarization of submillimetre masers. Tracing magnetic fields with ALMA
- An Arecibo Survey for Zeeman Splitting in OH Megamaser Galaxies
- A Review of Maser Polarization and Magnetic Fields
- Flares and Proper Motions of Ground-State OH Masers in W75N
- Masers and star formation