2009/09/21 by A. Sanna, M. J. Reid, L. Moscadelli +5 · 68 citations
Physics and Astronomy · #Astrometry #Astrophysical Phenomena and Observations #Astrophysics and Star Formation Studies #Galactic Center #Galaxy #Kinematics #Maser #Mass distribution #Parallax #Peculiar velocity #Proper motion #Radial velocity #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.1088/0004-637x/706/1/464
published in The Astrophysical Journal 706(1), 464-470 (IOP Publishing) · 16 pages, 4 figures, 2 tables, accepted by The Astrophysical Journal
arxiv created 2009/09/21 · openalex publication_date 2009/11/02 · arxiv updated 2014/11/20 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report a trigonometric parallax of 12 GHz methanol masers associated with the massive star-forming region G9.62+0.20, corresponding to a distance of 5.2 +0.6 −0.6 kpc. With an LSR velocity of about 2 km s −1 , the region's kinematic distances of 0.5 and 16 kpc differ greatly from the distance derived here. Our measurement of the peculiar motion of the star-forming region shows a very large deviation from a circular Galactic orbit: 41 km s −1 radially outward from the Galactic center and 60 km s −1 counter to Galactic rotation. The combination of its radial velocity and distance places G9.62+0.20 in the inner region of the Galaxy close to the expanding near 3 kpc arm, where the bulge/bar potential has strong gravitational influence. We also map the distribution of 12 GHz methanol masers, locate them with respect to a hypercompact H ii region, and compare our data with the periodic flare phenomenon reported previously for this source.