Galactic kinematics of various stellar types

TL;DR

This paper analyzes the kinematic differences among various stellar types, revealing how age, population, and peculiarities influence their spatial and velocity distributions in the galaxy.

Contribution

It provides a comparative analysis of stellar kinematics across multiple star classes, highlighting the significance of velocity ellipsoid deviations and phase space distributions.

Findings

Young stars cluster near the solar parabola in KE vs. LZ space.

Older stars occupy the central parabolic region, indicating elliptical orbits.

Certain peculiar stars deviate from typical kinematic trends.

Abstract

We compare and contrast the kinematics of various classes of stars, both normal (with M-K spectral types) and peculiar. Numerous plots show the differences in spatial and velocity distributions as well as distributions in kinetic energy vs. angular momentum (KE vs. LZ) space. In the latter plots, young, thin disk stars on nearly circular orbits cling to the left edge of a so-called solar parabola, while older objects on elliptical orbits fill the central parabolic region. Some of the young Wolf-Rayet stars violate this trend due to smaller semi-major axes than the Sun or orbital eccentricities. Deviation of the vertex of the velocity ellipsoid is discussed as an indication of population and youth, with an emphasis on Ap, Bp, Am, Fm, Herbig AeBe, and lambda Boo stars. Both the vertex deviation and phase space distribution provide useful insights.