ИСТИНА

We analyze the structure and kinematics of the currently most extensive sample of 123 Galactic maser sources associated with young stars and with published trigonometric parallaxes, radial velocities, and proper motions measured using VLBI technique (BESSEL and VERA surveys). We use a modification of the statistical-parallax technique based on the maximum-likelihood method to validate the trigonometricparallax based distance scale (which we find to be correct within the errors) and determine (1) the solar Galactocentric distance Ro ~ 8.3 ± 0.3 kpc, (2) the parameters of the Galactic rotation curve in the Galactocentric distance range spanning from 1 kpc to the outskirts of the Galactic thin disk (about 15 kpc), (3) velocity of the residual solar motion, (4) Galactocentric distance dependent components of the velocity dispersion tensor, (5) the radial disk scale length, and (6) the parameters of the perturbations induced by the spiral density wave (the pitch angle, the amplitudes of the radial and tangential perturbations, and the phase of the Sun).