Re-determining the Galactic spiral density wave parameters from data on masers with trigonometric parallaxes

Abstract

The parameters of the Galactic spiral wave are re-determined using a modified periodogram (spectral) analysis of the galactocentric radial velocities of 58 masers with known trigonometric parallaxes, proper motions, and line-of-site velocities. The masers span a wide range of galactocentric distances, $3<$R$<14$ kpc, which, combined with a large scatter of position angles $\theta$ of these objects in the Galactic plane XY, required an accurate account of logarithmic dependence of spiral-wave perturbations on both galactocentric distance and position angle. A periodic signal was detected corresponding to the spiral density wave with the wavelength $\lambda =2.4\pm 0.4$ kpc, peak velocity of wave perturbations $f_R=7.5\pm 1.5$ km s${}^{-1}$, the phase of the Sun in the density wave ${\chi }_{\odot }=-160\pm 15^{\circ }$, and the pitch angle of $-5.5\pm 1^{\circ }$.

6 pages, 5 figures, 1 table. Astron. Nachrichten (submitted). arXiv admin note: text overlap with arXiv:1208.4565

References in corpus (5)

• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
• Galactic masers and the Milky Way circular velocity
• Galactic Parameters from Masers with Trigonometric Parallaxes
• Redetermination of Galactic Spiral Density Wave Parameters Based on Spectral Analysis of Maser Radial Velocities
• Periodic Pattern in the Residual-Velocity Field of OB Associations

Cited by in corpus (2)

• Galactic masers: kinematics, spiral structure and the disk dynamic state
• Recent advances in the determination of some Galactic constants in the Milky Way