Analysis of Galactic Rotation from Masers based on a Nonlinear Oort Model

Abstract

Based on data on Galactic masers with measured trigonometric parallaxes, we have tested a nonlinear model of Galactic rotation using generalized Oort formulas. This model is shown to yield pretty good results up to heliocentric distances of 3--4 kpc. The main feature of the method is the possibility of estimating the solar Galactocentric distance Ro. This distance has been found by analyzing approximately 60 masers to be Ro=8.3+/-0.4 kpc. Our study of the three-dimensional kinematics of more than 100 masers based on the Ogorodnikov--Milne model has shown that significant nonlinearities are present only in the xy plane (rotation around the Galactic z axis) due to the peculiarities of the Galactic rotation curve. No significant linear dependences have been found in the xz and yz planes. We show the presence of a wave in the velocities w as a function of coordinate x or distance R with a wavelength of 3 kpc and an amplitude of 10 km/s. The wave is particularly prominent in the Local and Perseus arms.

14 pages, 6 figures. arXiv admin note: text overlap with arXiv:1406.0699

References in corpus (12)

• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
• VLBA determination of the distance to nearby star-forming regions I. The distance to T Tauri with 0.4% accuracy
• Radial and vertical flows induced by galactic spiral arms: likely contributors to our "wobbly Galaxy''
• Milky Way Kinematics: Measurements at the Subcentral Point of the Fourth Quadrant
• The Milky Way Rotation Curve and its Vertical Derivatives Inside the Solar Circle
• The Vertical Structure and Kinematics of Grand Design Spirals
• Galactic Rotation Parameters from Data on Open Star Clusters
• Kinematics of the Gould Belt Based on Open Clusters
• Determination of Galactic Rotation Parameters and the Solar Galactocentric Distance Ro from 73 Masers
• Distance and proper motion measurement of water masers in Shapless 269 IRS 2w
• VLBI Observations of H2O Maser Annual Parallax and Proper Motion in IRAS 20143+3634: Reflection on the Galactic Constants
• Structure and Dynamics of the Milky Way: The Evolving Picture

Cited by in corpus (3)

• Galactic Kinematics from Data on Open Star Clusters from the MWSC Catalogue
• Calibrating the BHB Star Distance Scale and the Halo Kinematic Distance to the Galactic Centre
• Place of the Radcliffe Wave in the Local System