A Large Stellar Evolution Database for Population Synthesis Studies. II. Stellar Models and Isochrones for an α-enhanced Metal Distribution

By Adriano Pietrinferni, Santi Cassisi, Maurizio Salaris, Fiorella Castelli. 2006

497 citations recorded by the source corpus.

We present a large, new set of stellar evolution models and isochrones for an α-enhanced metal distribution typical of Galactic halo and bulge stars; it represents a homogeneous extension of our stellar model library for a scaled-solar metal distribution already presented by Pietrinferni et al. The effect of the α-element enhancement has been properly taken into account in the nuclear network, opacity, equation of state, and for the first time in the bolometric corrections and color transformations. This allows us to avoid the inconsistent use—common to all α-enhanced model libraries currently available—of scaled-solar bolometric corrections and color transformations for α-enhanced models and isochrones. We show how bolometric corrections to magnitudes obtained for the U, B portion of stellar spectra for Teff ≤ 6500 K are significantly affected by the metal mixture, especially at the higher metallicities. Our models cover both an extended mass range (between 0.5 and 10 M☉, with a fine mass spacing) and a broad metallicity range, including 11 values of the metal mass fraction Z, corresponding to the range -2.6 ≤ [Fe/H] ≤ 0.05. The initial He mass fraction is Y = 0.245 for the most metal-poor models, and it increases with Z, according to ΔY/ΔZ = 1.4. Models with and without the inclusion of overshoot from the convective cores during the central H-burning phase are provided, as well as models with different mass loss efficiencies. We also provide complete sets of evolutionary models for low-mass, He-burning stellar structures cover the whole metallicity range. This database, used in combination with our scaled-solar model library, is a valuable tool for investigating both Galactic and extragalactic simple and composite stellar populations, using stellar population synthesis techniques.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/4cb9635bb3fcb2838c1d5d5502ff1c0ac13e36da

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Citations in the corpus

• Toward a Better Understanding of Cosmic Chronometers: A New Measurement of H(z) at z ∼ 0.7 (2021, unknown): “…are generated with variable age, [Z/H], [α/Fe] parameters, and use an updated version of the same empirical stellar library (MILES, Falcón-Barroso et al. 2011), but are based on corrections from theoretical stellar spectra and assume different stellar isochrones (BaSTI, Pietrinferni et al. 2006).”
• UV-extended E-MILES stellar population models: young components in massive early-type galaxies (2016, methodology): “We adopted the non-canonical BaSTI models with the mass loss efficiency of the Reimers law (Reimers 1977) set to η = 0.4.”
• The Multiplicity of the Subgiant Branch of ω Centauri: Evidence for Prolonged Star Formation (2007, methodology): “The relation between color and TeA, as a function of [M/H] (by which we mean the global metallicity, including -enhancement), was derived from isochrones by Pietrinferni et al. (2004, 2006).”
• Scaled solar tracks and isochrones in a large region of the Z-Y plane. II. From 2.5 to 20 solar masses (2009, background): “Bono et al. (2000) presented intermediate-mass standard models with different helium and metal content (3≤ M ≤ 15M⊙), and Pietrinferni et al. (2004, 2006) database makes available stellar models and isochrones for scaled-solar andα-enhanced metal distributions in the mass range between 0.5 and 10M⊙…”
• REDDENING AND EXTINCTION TOWARD THE GALACTIC BULGE FROM OGLE-III: THE INNER MILKY WAY'S RV ∼ 2.5 EXTINCTION CURVE (2012, methodology): “• We use the synthetic HB calculator of the BaSTI stellar database (Pietrinferni et al. 2004, 2006) to estimate σI,RC,0 = 0.031 for a simple, old, metal-rich stellar population.”
• Evolutionary stellar population synthesis with MILES – II. Scaled-solar and α-enhanced models (2015, methodology): “We also employ the scaled-solar and α-enhanced isochrones of BaSTI (Pietrinferni et al. 2004, 2006).”
• THE ACS SURVEY OF GALACTIC GLOBULAR CLUSTERS. IX. HORIZONTAL BRANCH MORPHOLOGY AND THE SECOND PARAMETER PHENOMENON (2009, background): “Pietrinferni et al. (2009) compared stellar evolution models from the BaSTI library (Pietrinferni et al. 2004, 2006) with chemical compositions representative of the primordial and extreme groups.”
• The Double Subgiant Branch of NGC 1851: The Role of the CNO Abundance (2007, methodology): “We consider as representative of the “normal” stellar population in NGC 1851 models computed with the a-enhanced mixture (A[Fe/H]S p 0.4) employed by Pietrinferni et al. (2006), a metal mass fraction Z p 0.002, and Y p 0.248, corresponding to [Fe/H] p 1.31 (Yong & Grundahl [2008] have determined a…”
• The Dartmouth Stellar Evolution Database (2008, methodology): “Following Dotter et al. (2007), comparison isochrones were drawn from Pietrinferni et al. (2004, 2006); Cordier et al. (2007, hereafter BaSTI), Girardi et al. (2000, hereafter Padova), Vandenberg et al. (2006, hereafter Victoria-Regina (VR)), and Yi et al. (2003, 2004, hereafter Yale-Yonsei (Y2)).”
• The age–metallicity structure of the Milky Way disc using APOGEE (2017, result): “…on the basis of the BaSTI stellar evolution models (Pietrinferni et al. 2004), for which there also exists calculations for α-enhanced stars (Pietrinferni et al. 2006), which produced comparable estimates to the PARSEC models (after correcting for the fact that the lowest mass in the BaSTI…”
• New constraints on the chemical evolution of the solar neighbourhood and galactic disc(s) - improved astrophysical parameters for the Geneva-Copenhagen Survey (2011, methodology): “In order to study differences between different isochrones, we used grids of the BASTI11 (Pietrinferni et al. 2004, 2006, 2009) and Padova12 isochrones (Bertelli et al. 2008, 2009).”
• MULTIPLE STELLAR POPULATIONS IN 47 Tucanae (2011, methodology): “To compare the observations against synthetic photometry, we adopted the BaSTI isochrones13 (Pietrinferni et al. 2004, 2006) specifically calculated for the populations listed in Table 2, then determined Teff and log g for MS stars at MF814W = 4.85.”
• THE APOGEE RED-CLUMP CATALOG: PRECISE DISTANCES, VELOCITIES, AND HIGH-RESOLUTION ELEMENTAL ABUNDANCES OVER A LARGE AREA OF THE MILKY WAY'S DISK (2014, methodology): “We employ BaSTI models with [α/Fe] = 0.4 (Pietrinferni et al. 2006) with an overall metallicity of Z = 0.01 and Z = 0.02; [Fe/H] for these models is about 0.35 dex lower than for the equivalent solar-scaled models.”
• Gaia broad band photometry (2010, methodology): “Recently, new stellar evolution models appeared in the Padova database for low-mass stars and high-mass stars in a large region of the 15M⊙) and the Pietrinferni et al. (2004, 2006) extended database makes available stellar models and isochrones for scaled-solar andα-enhanced metal distribution for…”