Fundamental Properties of Co-Moving Stars observed by $Gaia$

TL;DR

This study derives fundamental parameters for co-moving stars observed by Gaia, providing insights into their masses, metallicities, ages, and binary properties, with implications for stellar evolution and galactic structure.

Contribution

The paper presents a comprehensive analysis of Gaia co-moving stars, estimating key stellar parameters and examining binary properties, which improves understanding of stellar populations.

Findings

Mass estimates are robust compared to previous studies.

Metallicity and age estimates have higher uncertainties.

Binary separation influences binding energies and lifetimes.

Abstract

We have estimated fundamental parameters for a sample of co-moving stars observed by $Gaia$ and identified by Oh et al. (2017). We matched the $Gaia$ observations to the 2MASS and WISE catalogs and fit MIST isochrones to the data, deriving estimates of the mass, radius, [Fe/H], age, distance and extinction to 9,754 stars in the original sample of 10,606 stars. We verify these estimates by comparing our new results to previous analyses of nearby stars, examining fiducial cluster properties, and estimating the power-law slope of the local present-day mass function. A comparison to previous studies suggests that our mass estimates are robust, while metallicity and age estimates are increasingly uncertain. We use our calculated masses to examine the properties of binaries in the sample, and show that separation of the pairs dominates the observed binding energies and expected lifetimes.