Water maser motions in W3(OH) and a determination of its distance

Abstract

We report phase-referencing VLBA observations of H2O masers near the star-forming region W3(OH) to measure their parallax and absolute proper motions. The measured annual parallax is 0.489 +/- 0.017 milli-arcseconds (2.04 +/- 0.07 kpc), where the error is dominated by a systematic atmospheric contribution. This distance is consistent with photometric distances from previous observations and with the distance determined from CH3OH maser astrometry presented in a related paper. We also find that the source driving the H2O outflow, the ``TW-object'', moves with a 3-dimensional velocity of > 7 km/s relative to the ultracompact HII region W3(OH).

14 pages, 6 figures, accepted to ApJ

References in corpus (1)

• Pulsar Parallaxes at 5 GHz with the Very Long Baseline Array

Cited by in corpus (21)

• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
• The distance to the Orion Nebula
• The Electron Temperature Gradient in the Galactic Disk
• A Parallactic Distance of 389 +24/-21 parsecs to the Orion Nebula Cluster from Very Long Baseline Array Observations
• The Evolution of the Multiplicity of Embedded Protostars I: Sample Properties and Binary Detections
• Galactic interstellar 18O/17O ratios - a radial gradient?
• Water maser variability over 20 years in a large sample of star-forming regions: the complete database
• The Diverse Stellar Populations of the W3 Star Forming Complex
• The Proper Motion of the Local Group Galaxy IC 10
• Compatibility of DAMA/LIBRA dark matter detection with other searches in light of new Galactic rotation velocity measurements
• Improved VLBI astrometry of OH maser stars
• The star-forming content of the W3 giant molecular cloud
• [Ne II] Observations of Gas Motions in Compact and Ultracompact H II Regions
• Structure of W3(OH) from Very High Spectral Resolution Observations of 5 Centimeter OH Masers
• Disk galaxy rotation curves and dark matter distribution
• Water masers in the Local Group of galaxies
• Interferometric Parallax: A Method for Measurement of Astronomical Distances
• Observations of the Goldreich-Kylafis effect in star-forming regions with XPOL at the IRAM 30m telescope
• Masers and star formation
• VLBA determinations of the distances to nearby star-forming regions
• Problems of Star Formation Theory and Prospects of Submillimeter Observations