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1. SDSS-IV MaStar: theoretical atmospheric parameters for the MaNGA stellar library

   https://doi.org/10.1093/mnras/stab3263  

   Hill, Lewis; Thomas, Daniel; Maraston, Claudia; Yan, Renbin; Neumann, Justus; Lundgren, Andrew; Lazarz, Daniel; Chen, Yan-Ping; Cappellari, Michele; Holtzman, Jon A.; et al (November 2021, Monthly Notices of the Royal Astronomical Society)

   ABSTRACT We calculate the fundamental stellar parameters effective temperature, surface gravity, and iron abundance – Teff, log g, [Fe/H] – for the final release of the Mapping Nearby Galaxies at APO (MaNGA) Stellar Library (MaStar), containing 59 266 per-visit-spectra for 24 290 unique stars at intermediate resolution (R ∼ 1800) and high S/N (median = 96). We fit theoretical spectra from model atmospheres by both MARCS and BOSZ-ATLAS9 to the observed MaStar spectra, using the full spectral fitting code pPXF. We further employ a Bayesian approach, using a Markov Chain Monte Carlo (MCMC) technique to map the parameter space and obtain uncertainties. Originally in this paper, we cross match MaStar observations with Gaia photometry, which enable us to set reliable priors and identify outliers according to stellar evolution. In parallel to the parameter determination, we calculate corresponding stellar population models to test the reliability of the parameters for each stellar evolutionary phase. We further assess our procedure by determining parameters for standard stars such as the Sun and Vega and by comparing our parameters with those determined in the literature from high-resolution spectroscopy (APOGEE and SEGUE) and from lower resolution matching template (LAMOST). The comparisons, considering the different methodologies and S/N of the literature surveys, are favourable in all cases. Our final parameter catalogue for MaStar cover the following ranges: 2592 ≤ Teff ≤ 32 983 K; −0.7 ≤ log g ≤ 5.4 dex; −2.9 ≤ [Fe/H] ≤ 1.0 dex and will be available with the last SDSS-IV Data Release, in 2021 December. 

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2. SDSS-IV MaStar: a Large, Comprehensive, and High Quality Empirical Stellar Library

   Yan, Renbin MaStar Team (January 2017, ASI Conference Series)

   We introduce the ongoing MaStar project, which is going to construct a large, well-calibrated, high quality empirical stellar library with more than 8000 stars covering the wavelength range 3,622 - 10,354Å at a resolution of R̃2000, and with better than 3% relative flux calibration. The spectra are taken using hexagonal fibre bundles feeding the BOSS spectrographs on the 2.5m Sloan Foundation Telescope, by piggybacking on the SDSS-IV/APOGEE-2 observations. Compared to previous efforts of empirical libraries, the MaStar Library will have a more comprehensive stellar parameter coverage, especially in cool dwarfs, low metallicity stars, and stars with different [α/Fe]. This is achieved by a target selection method based on large spectroscopic catalogs from APOGEE, LAMOST, and SEGUE, combined with photometric selection. This empirical library will provide a new basis for calibrating theoretical spectral libraries and for stellar population synthesis. In addition, with identical spectral coverage and resolution to the ongoing integral field spectroscopy survey of nearby galaxies -- SDSS-IV/MaNGA (Mapping Nearby Galaxies at APO). this library is ideal for spectral modelling and stellar population analysis of MaNGA data. 

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3. SDSS-IV MaStar: A Large and Comprehensive Empirical Stellar Spectral Library—First Release

   https://doi.org/10.3847/1538-4357/ab3ebc  

   Yan, Renbin; Chen, Yanping; Lazarz, Daniel; Bizyaev, Dmitry; Maraston, Claudia; Stringfellow, Guy S.; McCarthy, Kyle; Meneses-Goytia, Sofia; Law, David R.; Thomas, Daniel; et al (October 2019, The Astrophysical Journal)
4. Stellar Parameters for the First Release of the MaSTar Library: An Empirical Approach

   https://doi.org/10.3847/1538-4357/ab9f35  

   Chen, Yan-Ping; Yan, Renbin; Maraston, Claudia; Thomas, Daniel; Stringfellow, Guy S.; Bizyaev, Dmitry; Gelfand, Joseph D; Beers, Timothy C.; Fernández-Trincado, José G.; Lazarz, Daniel; et al (August 2020, The Astrophysical Journal)
5. Stellar Population Models Based on the Milky Way Interstellar Medium-Corrected MaStar Stellar Library

   https://doi.org/10.5281/zenodo.14807331  

   Maraston, Claudia; Thomas, Daniel; Rubin, Kate; Westfall, Kyle; Yan, Renbin; Howk, J Christopher; Aguirre, Erick; Parker, Kaelee; Law, David (January 2025, Zenodo)

   {"Abstract":["This file contains simple stellar population (SSP) model spectra constructed from a version of the SDSS-IV MaNGA Stellar Library (MaStar; Yan et al. 2019, Abdurro'uf et al. 2022) that has been corrected for the effects of absorption in the CaII 3934, 3969 and NaI D 5891, 5897 transitions arising in the Milky Way's interstellar medium (ISM).  These corrections are described in full in Rubin et al. (2025), and our approach to constructing these SSP models is described in Maraston et al. (2020) and Rubin et al. (2025).  In brief, our models are calculated with the evolutionary population synthesis code of Maraston (2005), which is based on the fuel consumption theorem for the evaluation of the energetics of post-Main Sequence phases.  We use the calibrated median values of the stellar parameters calculated for the MaStar sample to generate representative stellar spectra as functions of effective temperature, surface gravity, and chemical composition.  These representative spectra are then used as input for the stellar population models.  The stellar parameter estimates are described in R. Yan et al. (2025, in preparation) and at https://www.sdss4.org/dr17/mastar/mastar-stellar-parameters/.  \n\nWe calculate SSPs using stars in metallicity bins centered at [Z/H] = -1.35, -0.33, 0.0, and +0.35 with an approximate bin width of 0.1 dex assuming a Salpeter IMF.  The SSP ages span 3 Myr to 15 Gyr and are calculated at 51 gridpoints.  For comparison, we also calculate the equivalent SSPs using the uncorrected MaStar spectra.  The datamodel is described below.\n\nHDU1: 51 x 4 x 1 x 3 matrix describing the parameters of each SSP spectrum.  Each gridpoint (i,j,k) contains a 3-element array listing the age (in Gyr), metallicity, and IMF slope (in linear mass units)\n\nHDU2: 2 x 4563 array containing the vacuum wavelength and spectral resolution (R) grids for models constructed from the uncorrected (original) stellar library.  The wavelength sampling is logarithmic and the wavelengths have units of Angstroms.  R = wave / (FWHM dwave)\n\nHDU3: 51 x 4 x 1 x 4563 matrix containing the SSPs constructed from the uncorrected (original) stellar library in units of erg/s/Ang/Msun  \n\nHDU4: 2 x 4542 array containing the vacuum wavelength and spectral resolution (R) grids for models constructed from the corrected (cleaned) stellar library.  The wavelength sampling is logarithmic and the wavelengths have units of Angstroms.  R = wave / (FWHM dwave)\n\nHDU5: 51 x 4 x 1 x 4542 matrix containing the SSPs constructed from the corrected (cleaned) stellar library in units of erg/s/Ang/Msun  "],"Other":["Preferred Citation\n\nIf you use these model spectra in your research, we ask that you please cite our article, "Sloan Digital Sky Survey IV MaStar: Quantification and Abatement of Interstellar Absorption in the Largest Empirical Stellar Spectral Library," Rubin et al. (2025), ApJ, 981 31, doi:10.3847/1538-4357/ad8eb6.  Please also cite this Zenodo deposit."]} 

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