On the Possibility of Determining the Distance to the Galactic Center from the Geometry of Spiral Arm Segments

Abstract

A new approach to determining the solar galactocentric distance, R0, from the geometry of spiral-arm segments is proposed. Geometric aspects of the problem are analyzed and a simplified three-point method for estimating R0 from objects in a spiral segment is developed in order to test the proposed approach. An estimate of R0 = 8.44 ± 0.45 kpc is obtained by applying the method to masers with measured trigonometric parallaxes, and statistical properties of the R0 estimation from spiral segments are analyzed.

Keywords

• galaxy: structure
• galaxy: fundamental parameters
• masers