2019/01/27 by Y. W. Wu, Y. W. 元伟 Wu 吴, M. J. Reid +16
Physics and Astronomy · #Astrometry #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Logarithmic spiral #Maser #Milky Way #Parallax #Sagittarius #Spiral (railway) #Spiral galaxy #Stellar, planetary, and galactic studies #Tangent #Tangent bundle #astro-ph.GA
paper · pdf · doi:10.3847/1538-4357/ab001a
ApJ accepted. 36 pages, 8 figures and 2 tables
arxiv created 2019/01/27 · openalex created_date 2019/02/21 · openalex publication_date 2019/03/20 · arxiv updated 2019/04/03 · openalex updated_date 2026/08/05
Abstract As part of the BeSSeL Survey, we report trigonometric parallaxes and proper motions of molecular maser sources associated with 13 distant high-mass star-forming regions in the Sagittarius spiral arm of the Milky Way. In particular, we obtain improved parallax distance estimates for three well-studied regions: for M17, for W51, and for GAL 045.5+00.0. Peculiar motions for all but one source are less than 20 km s −1 . We fit a log-periodic spiral to the locations and estimate an average pitch angle of 7.°2 ± 1.°9. We find that the section of the arm beyond the tangent point in the first quadrant of the Milky Way appears 15 pc below the IAU-defined Galactic plane.