The Victoria‐Regina Stellar Models: Evolutionary Tracks and Isochrones for a Wide Range in Mass and Metallicity that Allow for Empirically Constrained Amounts of Convective Core Overshooting

TLDR

The study presents 72 grids of stellar evolutionary tracks and tools for generating isochrones and luminosity/color functions. These grids span masses 0.4–4.0 M⊙ and metallicities from [Fe/H] = –2.31 to +0.49, extend previous VandenBerg models, and incorporate convective core overshooting via a parameterized Roxburgh criterion calibrated on binary data and open‑cluster CMDs. The resulting models satisfy numerous empirical constraints and can serve as reliable probes of both simple and complex stellar populations.

Abstract

Seventy-two grids of stellar evolutionary tracks, along with the means to generate isochrones and luminosity/color functions from them, are presented in this investigation. Sixty of them extend (and encompass) the sets of models reported by VandenBerg et al. for 17 [Fe/H] values from -2.31 to -0.30 and α-element abundances corresponding to [α/Fe] = 0.0, 0.3, and 0.6 (at each iron abundance) to the solar metallicity and to sufficiently high masses (up to ~2.2 M☉) that isochrones may be computed for ages as low as 1 Gyr. The remaining grids contain tracks for masses from 0.4 to 4.0 M☉ and 12 [Fe/H] values between -0.60 and +0.49 (assuming solar metal-to-hydrogen number abundance ratios): in this case, isochrones may be calculated down to ~0.2 Gyr. The extent of convective core overshooting has been modeled using a parameterized version of the Roxburgh criterion, in which the value of the free parameter at a given mass and its dependence on mass have been determined from analyses of binary star data and the observed color-magnitude diagrams for several open clusters. Because the calculations reported herein satisfy many empirical constraints, they should provide useful probes into the properties of both simple and complex stellar populations.