3D motions of 6.7 GHz methanol masers and effects of the Galactic bar
Abstract
To search for kinematic evidence of the existence of the Galactic bar, we observed 10 methanol maser sources at the near end of the bar with VERA (VLBI Exploration of Radio Astrometry). From these observations, we obtained absolute proper motions of eight sources based on the phase-referencing technique. We compared the motions with the predictions of three simple models in a 3D plane. This comparison showed that a non-flat circular rotation model and a dynamical model including a bar potential reproduce the observed data better than a flat rotation model. In addition, the bar model suggests that the inclination angle of the Galactic bar is around 35°, which is consistent with previous studies.
- Publication:
-
Advancing the Physics of Cosmic Distances
- Pub Date:
- February 2013
- DOI:
- 10.1017/S1743921312021837
- Bibcode:
- 2013IAUS..289..410M
- Keywords:
-
- masers;
- astrometry;
- Galaxy: kinematics and dynamics;
- radio lines: ISM