The spiral density-wave structure of the Milky Way in the 3-kpc-scale solar neighbourhood: line-of-sight velocities of 252 young open clusters

Abstract

ABSTRACT Following Lin and Shu, the spiral structure in the Milky Way disc is considered as an oscillating density-wave pattern. As such, regular enhancements in density are relatedly linked to systematic variations in velocity of young stars and stellar clusters, and interstellar gas. We explain measured line-of-sight velocities of 252 open clusters with ages <100 Myr of Tarricq et al. in the 3-kpc-scale solar neighbourhood in terms of a density wave. New estimates of the parameters of solar peculiar motion and Galactic differential rotation corrected for the effects of small-amplitude density waves, the radial and tangential components of systematic motion of clusters due to the spiral arms as well as the geometrical and dynamical parameters of the waves are suggested.