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

@misc{chen2026sdssiv,
  title = {{SDSS-IV MaStar: Determination of Stellar Parameters Using Bayesian Averaging}},
  author = {Yan-Ping Chen and Renbin Yan and Szabolcs Mészáros and Claudia Maraston and Daniel Thomas and Daniel Lazarz and Guy S. Stringfellow and Lewis Hill and Julie Imig and Joseph D. Gelfand and Jon A. Holtzman and Matthew Bershady and Dmitry Bizyaev and Niv Drory and Keivan G. Stassun},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.13455},
  eprint = {2609.13455},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.13455},
}

TY  - UNPB
TI  - SDSS-IV MaStar: Determination of Stellar Parameters Using Bayesian Averaging
AU  - Yan-Ping Chen
AU  - Renbin Yan
AU  - Szabolcs Mészáros
AU  - Claudia Maraston
AU  - Daniel Thomas
AU  - Daniel Lazarz
AU  - Guy S. Stringfellow
AU  - Lewis Hill
AU  - Julie Imig
AU  - Joseph D. Gelfand
AU  - Jon A. Holtzman
AU  - Matthew Bershady
AU  - Dmitry Bizyaev
AU  - Niv Drory
AU  - Keivan G. Stassun
PY  - 2026
DA  - 2026/09/11
PB  - arXiv
DO  - 10.48550/arxiv.2609.13455
UR  - https://arxiv.org/abs/2609.13455
AB  - 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 {α}-enhancement ratio ([α/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 ≤ T_eff ≤ 29,861 K, a surface gravity range of 0 ≤ log g ≤ 5.5, a metallicity range of −4.9 ≤ [M/H] ≤ 1.0, and an {α}-abundance range of -0.98 ≤ [α/M] ≤ 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/).
ER  -