Determination of the Solar Galactocentric distance from masers kinemics

TL;DR

This study accurately determines the solar Galactocentric distance and Galactic rotation parameters using VLBI maser data, providing refined values for key Galactic constants and rotation velocities.

Contribution

It presents a new, precise measurement of the solar Galactocentric distance and Galactic rotation parameters based on a large sample of masers with VLBI data.

Findings

Galactic rotation parameters are precisely estimated.

Solar Galactocentric distance R_0 = 8.03 +/- 0.12 kpc.

Rotation velocity at R_0 is 238 +/- 6 km/s.

Abstract

We have determined the Galactic rotation parameters and the solar Galactocentric distance $R_0$ by simultaneously solving Bottlinger's kinematic equations using data on masers with known line-of-sight velocities and highly accurate trigonometric parallaxes and proper motions measured by VLBI. Our sample includes 93 masers spanning the range of Galactocentric distances R from 3 to 15 kpc. The solutions found are \Omega_0 = 29.7+/-0.5 km s^{-1} kpc^{-1}, \Omega'_0 = -4.20+/-0.11 km s^{-1} kpc^{-2}, \Omega"_0 =0.730+/-0.029 km s^{-1} kpc^{-3}, and R_0=8.03+/-0.12 kpc. In this case, the linear rotation velocity at the solar distance R_0 is V_0=238+/-6 km s^{-1}.