A Statistical Relation between Mass, Age and Velocity Dispersion in the Solar Neighborhood

TL;DR

This study reveals a significant correlation between stellar mass, age, and velocity dispersion in the Solar neighborhood, using Gaia data and machine learning to improve understanding of Galactic disk dynamics.

Contribution

It introduces a novel analysis of the combined effects of stellar mass and age on velocity dispersion using Random Forest regression on Gaia data.

Findings

Velocity dispersion can be predicted with about 9% error considering mass and age.

Stellar age correlates 3 to 8 times more strongly with velocity dispersion than mass.

The method improves understanding of stellar kinematics in the Galactic disk.

Abstract

The stellar kinematics of the Galactic disk are main factors for constraining disk formation and evolution processes in the Milky Way (MW) Galaxy. In this paper we investigate a statistical relation between stellar Mass, Age and Velocity Dispersion for stars in the Solar neighborhood. Age-Velocity dispersion relations (AVR), with their applications, have been studied in details before. But their correlation with mass was mostly neglected. To investigate this relation, we use the proper motion data of more than 113035 stars in the Galactic disk (with Solar distances less than 150 parsecs) provided by the third data release of the \textit{Gaia} mission and for stellar Mass and Age, \textit{Gaia}'s Final Luminosity Age Mass Estimator (\textit{FLAME}) is implemented. We analyze this data and the correlations between the parameters with Random Forrest (RF) Regression, which is an Ensemble statistical learning technique. Finally, we show that by considering the stellar mass alongside age, we can determine Velocity Dispersions with the average relative error, and mean absolute error of about $9\%$, and $2.68~\rm{km/s}$, respectively. We also find that the correlation of stellar age with Velocity Dispersion is $3$ to $8$ times more than mass, which varies due to the different stellar types and masses.