sMILES SSPs: A Library of Semi-Empirical MILES Stellar Population Models with Variable [$\alpha$/Fe] Abundances

Abstract

We present a new library of semi-empirical stellar population models that are based on the empirical MILES and semi-empirical sMILES stellar libraries. The models span a large range of age and metallicity, in addition to an [$\alpha$/Fe] coverage from $-$0.2 to $+$0.6 dex, at MILES resolution (FWHM=2.5$\mathring{\mathrm{A}}$) and wavelength coverage (3540.5-7409.6$\mathring{\mathrm{A}}$). These models are aimed at exploring abundance ratios in the integrated light from stellar populations in star clusters and galaxies. Our approach is to build SSPs from semi-empirical stars at particular [$\alpha$/Fe] values, thus producing new SSPs at a range of [$\alpha$/Fe] values from sub-solar to super-solar. We compare these new SSPs with previously published and well-used models and find similar abundance pattern predictions, but with some differences in age indicators. We illustrate a potential application of our new SSPs, by fitting them to the high signal-to-noise data of stacked SDSS galaxy spectra. Age, metallicity and [$\alpha$/Fe] trends were measured for galaxy stacks with different stellar velocity dispersions and show systematic changes, in agreement with previous analyses of subsets of those data. These new SSPs are made publicly available.

21 pages, 18 figures plus Supplementary Material. Accepted for publication in MNRAS

References in corpus (22)

• Evolutionary Stellar Population Synthesis with MILES. Part I: The Base Models and a New Line Index System
• UV-extended E-MILES stellar population models: young components in massive early-type galaxies
• The Atlas3D Project - XXX. Star formation histories and stellar population scaling relations of early-type galaxies
• Evolutionary stellar population synthesis with MILES - II. Scaled-solar and α-enhanced models
• Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters
• A new library of theoretical stellar spectra with scaled-solar and alpha-enhanced mixtures
• The updated BaSTI stellar evolution models and isochrones: II. alpha-enhanced calculations
• Spectral models for solar-scaled and alpha-enhanced stellar populations
• A large stellar evolution database for population synthesis studies. IV. Integrated properties and spectra
• An optimized H_βindex for disentangling stellar population ages
• IMF and [Na/Fe] abundance ratios from optical and NIR Spectral Features in Early-type Galaxies
• Testing the Accuracy of Synthetic Stellar Libraries
• MILES extended: Stellar population synthesis models from the optical to the infrared
• Modelling simple stellar populations in the near-ultraviolet to near-infrared with the X-shooter Spectral Library (XSL)
• SPIDER X - Environmental effects in central and satellite early-type galaxies through the stellar fossil record
• To use or not to use synthetic stellar spectra in population synthesis models?
• Initial Mass Function Variability (or not) Among \\ Low-Velocity Dispersion, Compact Stellar Systems
• sMILES: A Library of Semi-Empirical MILES Stellar Spectra with Variable [$\alpha$/Fe] Abundances
• Mild radial variations of the stellar IMF in the bulge of M31
• SDSS-IV MaNGA: The [$\alpha$/Fe] of Early-Type Galaxies
• Individual element sensitivity for stellar evolutionary isochrones
• Analysis of stellar populations with large empirical libraries at high spectral resolution

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• Towards Precision Cosmology With Improved PNLF Distances Using VLT-MUSE. III. Impact of Stellar Populations in Early-Type Galaxy
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• A MaNGA about the Legacy I: Connecting the Assembly of Stellar Halo with the Average Star Formation History in Low-Redshift Massive Galaxies
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• Cosmography via stellar archaeology of low-redshift early-type galaxies from SDSS
• The Nuclear Star Cluster of M 74: a fossil record of the very early stages of a star-forming galaxy