Kinematics of Solar neighborhood stars and its dependency on age and metallicity

TL;DR

This study analyzes how stellar kinematics in the Solar neighborhood vary with age and metallicity using a new star catalog, revealing linear relationships and insights into Galactic dynamics.

Contribution

It introduces the ACAD catalog and applies the Lindblad-Oort Model to explore kinematic evolution with stellar age and metallicity.

Findings

Solar motion component S2 increases linearly with age

S2 also increases linearly with metallicity

No clear correlation between Sun's rotational velocity and stellar age/metallicity

Abstract

We have constructed a catalog containing best available astrometric, photometric, radial velocity and astrophysical data for mainly F-type and G-type stars (called the Astrometric catalog associated with Astrophysical Data, ACAD), which contains 27,553 records, and is used for the purpose of analyzing the stellar kinematics in the Solar neighborhood. Using the Lindblad-Oort Model and compiled ACAD, we calculated the Solar motion and Oort constants in different age/metallicity bins. The evolution of kinematical parameters with stellar age and metallicity were investigated directly. The results show that the component of the Solar motion in the direction of Galactic rotation (denoted $S_2$) has a linear increase with respect to age, which may be a consequence of the scattering processes, and its value for a dynamical cold disk was found to be $8.0\pm1.2~\mathrm{km~s^{-1}}$. $S_2$ also increases linearly with respect to metallicity, which indicates that radial migration is correlated to the metallicity gradient. On the other hand, the rotational velocity of the Sun around the Galactic center has no clear correlation with ages or metallicities of stars used in the estimation.