SDSS-IV MaStar: Determination of Stellar Parameters Using Bayesian Averaging

Abstract

We present the stellar parameters for 59,266 high-quality spectra of 24,130 unique stars from the MaNGA Stellar Library (MaStar) in the Sloan Digital Sky Survey (SDSS) Data Release 17 (DR17). The median signal-to noise ratio per pixel of the spectra is 96. We derive four stellar parameters, effective temperature (Teff), surface gravity (log g), metallicity ([M/H]), and {$\alpha$}-enhancement ratio ($[\alpha /M]$), by comparing the data with BOSZ (ATLAS-9 based) and MARCS theoretical atmospheric models. We adopt a Bayesian method and use color and absolute magnitude derived from Gaia to select a subset of theoretical models for each star. We then perform full-spectrum fitting to estimate the likelihood of each model in the subset and then compute their likelihood-weighted mean parameters as the final parameters. We set stellar-parameter quality flags to facilitate the use of the derived stellar parameters. The MaStar stellar parameters derived herein span an effective temperature range of $2,600\le {\mathrm{T}}_{\mathrm{eff}}\le 29,861K$, a surface gravity range of $0\le \log g\le 5.5$, a metallicity range of $-4.9\le [M/H]\le 1.0$, and an {$\alpha$}-abundance range of $-0.98\le [\alpha /M]\le 1.0$. We compare these parameters with those from APOGEE and Gaia for stars in common, finding general consistency within the uncertainties. However, some artifacts and systematic differences are present, and we discuss their potential causes. These new stellar parameters are available through the MaStar SDSS-IV DR17 value-added catalog (https://www.sdss4.org/dr17/mastar/mastar-stellar-parameters/).

27 pages, 20 figures

References in corpus (21)

• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• The 2.5 m Telescope of the Sloan Digital Sky Survey
• Overview of the SDSS-IV MaNGA Survey: Mapping Nearby Galaxies at Apache Point Observatory
• The GALAH Survey: Scientific Motivation
• Improving PARSEC models for very low mass stars
• New PARSEC evolutionary tracks of massive stars at low metallicity: testing canonical stellar evolution in nearby star forming dwarf galaxies
• The MaNGA Integral Field Unit Fiber Feed System for the Sloan 2.5 m Telescope
• APOGEE Data and Spectral Analysis from SDSS Data Release 16: Seven Years of Observations Including First Results from APOGEE-South
• The Data Reduction Pipeline for the SDSS-IV MaNGA IFU Galaxy Survey
• A new library of theoretical stellar spectra with scaled-solar and alpha-enhanced mixtures
• Spectroscopic ages and metallicities of stellar populations: validation of full spectrum fitting
• Spectral models for solar-scaled and alpha-enhanced stellar populations
• The Gaia-ESO Public Spectroscopic Survey: Motivation, implementation, GIRAFFE data processing, analysis, and final data products
• The X-shooter Spectral Library (XSL): I. DR1. Near-ultraviolet through optical spectra from the first year of the survey
• The Extended IRTF Spectral Library: Expanded coverage in metallicity, temperature, and surface gravity
• SDSS-IV MaNGA: Modeling the Spectral Line Spread Function to Sub-Percent Accuracy
• 4MOST Consortium Survey 7: Wide-Area VISTA Extragalactic Survey (WAVES)
• ATLAS and SYNTHE under Linux
• SDSS-IV MaStar: Data-driven Parameter Derivation for the MaStar Stellar Library
• Stellar parameters for the First Release of the MaStar Library: An Empirical Approach
• SDSS-IV MaStar: Stellar Parameter Determination with Continuum-Supplemented Full-Spectrum Fitting