The galactic disc age-metallicity relation

TL;DR

This paper revises stellar ages in the Solar Neighbourhood using Hipparcos data, finding no clear age-metallicity relation for stars younger than 10 Gyr, but a possible relation for older stars, and compares it with other methods.

Contribution

It provides new age estimates for nearby stars with improved accuracy and analyzes the age-metallicity relation across different stellar populations and models.

Findings

No clear age-metallicity relation for stars younger than 10 Gyr.

A potential slope of ~0.07 dex/Gyr for older stars.

Comparison with other methods shows varying relations.

Abstract

New ages are computed for stars in the Solar Neighbourhood from the Edvardsson et al. (1993) data set. Distances derived from the Hipparcos parallaxes were adopted to obtain reliable ages (uncertainty less than 12%) for a subset of stars. There is no apparent age-metallicity relation for stars with an age less than 10 Gyr. Only if we consider older stars a slope of ~0.07 dex/Gyr appears. This relation is compared with those obtained from other methods, i.e. galactic open clusters, stellar population synthesis (star counts), and chemical evolution models.