Errors in kinematic distances and our image of the Milky Way Galaxy

Abstract

Errors in the kinematic distances, under the assumption of circular gas orbits, were estimated by performing synthetic observations of a model disk galaxy. It was found that the error is < 0.5 kpc for most of the disk when the measured rotation curve was used, but larger if the real rotation curve is applied. In both cases, the error is significantly larger at the positions of the spiral arms. The error structure is such that, when kinematic distances are used to develope a picture of the large scale density distribution, the most significant features of the numerical model are significantly distorted or absent, while spurious structure appears. By considering the full velocity field in the calculation of the kinematic distances, most of the original density structures can be recovered.

Accepted for publication in AJ

Cited by in corpus (13)

• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
• The origin of large peculiar motions of star-forming regions and spiral structures of our Galaxy
• The Hi-GAL catalogue of dusty filamentary structures in the Galactic Plane
• From diffuse gas to dense molecular cloud cores
• The incorrect rotation curve of the Milky Way
• The Galactic distribution of magnetic fields in molecular clouds and HII regions
• Testing kinematic distances under a realistic Galactic potential
• Interstellar Extinction
• Streaming Motions and Kinematic Distances to Molecular Clouds
• Three-Dimensional Reddening Map for Stars from 2MASS Photometry: The Method and the First Results
• Kinetic tomography of the Galactic plane within 1.25 kiloparsecs from the Sun. The interstellar flows revealed by HI and CO line emission and 3D dust
• Autonomous Gaussian decomposition of the Galactic Ring Survey. II. The Galactic distribution of 13CO
• The distances of 61 PGCCs in the Second Galactic Quadrant