Mapping Spiral Structure on the far side of the Milky Way

Abstract

Little is known about the portion of the Milky Way lying beyond the Galactic center at distances of more than 9 kilo-parsec from the Sun. These regions are opaque at optical wavelengths due to absorption by interstellar dust, and distances are very large and hard to measure. We report a direct trigonometric parallax distance of 20.4_{-2.2}^{+2.8} kilo-parsec obtained with the Very Long Baseline Array to a water maser source in a region of active star formation. These measurements allow us to shed light on Galactic spiral structure by locating the Scutum-Centaurus spiral arm as it passes through the far side of the Milky Way, and to validate a kinematic method for determining distances in this region based on transverse motions.

21 pages, 5 figures, 4 tables, published in Science, October 13 issue

References in corpus (6)

• DiFX: A software correlator for very long baseline interferometry using multi-processor computing environments
• Trigonometric parallaxes of star forming regions in the Sagittarius spiral arm
• Trigonometric Parallaxes of Star Forming Regions in the Perseus Spiral Arm
• Trigonometric Parallaxes of Star Forming Regions in the Scutum Spiral Arm
• Characteristics of Spiral Arms in Late-type Galaxies
• First Parallax Measurements Towards a 6.7 GHz Methanol Maser with the Australian Long Baseline Array - Distance to G339.884-1.259

Cited by in corpus (23)

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• Local spiral structure based on the Gaia EDR3 parallaxes
• The Bar and Spiral Arms in the Milky Way: Structure and Kinematics
• Comparison of Gaia DR2 Parallaxes of Stars with VLBI Astrometry
• What Does the Milky Way Look Like?
• Anomalous peculiar motions of high-mass young stars in the Scutum spiral arm
• Parallaxes for star forming regions in the inner Perseus spiral arm
• Using classical Cepheids to study the far side of the Milky Way disk. II. The spiral structure in the first and fourth Galactic quadrants
• On the Accuracy of Three-dimensional Kinematic Distances
• Modeling of Spiral Structure in a Multi-Component Milky~Way-Like Galaxy
• Geometric optics in relativistic cosmology: new formulation and a new observable
• Resolving the distance controversy for Sharpless 269: A possible kink in the outer arm
• The distance to the Serpens South Cluster from H2O masers
• A New Multi-Tracer Approach to Defining the Spiral arm width in the Milky Way
• Parameters of the Galactic Spiral Density Wave from Masers with Parallax Errors Less Than 10%
• The Science of Fundamental Catalogs
• EAVN Astrometry toward the Extreme Outer Galaxy: Kinematic distance with the proper motion of G034.84-00.95
• Discovery of 22 GHz Water Masers in the Serpens South Region
• Testing the null energy condition with precise distance measurements
• Assessing the stellar population and the environment of an HII region on the far side of the Galaxy