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

Abstract

Seventy-two grids of stellar evolutionary tracks, along with the capability to generate isochrones and luminosity/color functions from them, are presented in this investigation. 1 Sixty of them extend (and encompass) the sets of models reported by VandenBerg et al. (2000, ApJ, 532, 430) 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 ∼ 2.2M ⊙ ) 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 modelled using a parameterized version of the Roxburgh (1989, A&A, 211, 361) criterion, in which the 1 All of the model grids may be obtained from the Canadian Astronomy Data Center (http://www.cadc-ccda.hiaiha.nrc-cnrc.gc.ca/cvo/community/VictoriaReginaModels/). Included in this archive are (i) the interpolation software (FORTRAN 77) to produce isochrones, isochrone probability functions, luminosity functions, and color functions, along with instructions on how to implement and use the software, (ii) BV RI (VandenBerg & Clem 2003) and uvby (Clem et al. 2004) color-temperature relations, and (iii) Zero-Age Horizontal Branch loci for all of the chemical compositions considered.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.

WASP-52b, WASP-58b, WASP-59b, and WASP-60b: Four new transiting close-in giant planets

“…For comparison, the stellar mass was also derived from mass tracks in ρ * -vs.-T eff HR diagrams (Sozzetti et al 2007). We compared several models for the tracks in the HR diagrams: the Padova isochrones of Marigo et al (2010), the Teramo stellar models from Pietrinferni et al (2004), the Victoria-Regina stellar models from Vandenberg et al (2006), and the Yonsei-Yale isochrones of Demarque et al (2004). The last among these are plotted in Fig.…”

Physical properties of the HAT-P-23 and WASP-48 planetary systems from multi-colour photometry

“…Following the methodology used by Southworth (2010), the main physical parameters of the TEP systems HAT-P-23 and WASP-48 were found from the photometric parameters deduced from the parameters available in the literature (see Table 7 for values and references), and by interpolating within the tabulated predictions of five sets of theoretical stellar models (Claret 2004b;Demarque et al 2004;Pietrinferni et al 2004;VandenBerg et al 2006;Dotter et al 2008). In brief, an initial estimate of the stellar mass was specified and the observed quantities were compared to the ones predicted by stellar models for this mass.…”

A close look at the Centaurus A group of galaxies

“…There is a well known degeneracy in this evolutionary stage, such that stars that are younger and more metal-rich may be found in the same RGB region as stars that are older and more metal-poor. Ideally, for a "simple" stellar population a spread in age would produce a narrower RGB at the same metallicity than would a spread in metallicity at a constant age (see, for example, VandenBerg et al 2006). Owing to the relatively small number of luminous AGB stars above the TRGB, we may assume that the majority of the RGB stars belong to old populations (10 Gyr or older).…”