{
  "id": "2410.16730",
  "version": "v1",
  "published": "2024-10-22T06:29:38.000Z",
  "updated": "2024-10-22T06:29:38.000Z",
  "title": "An Empirical Sample of Spectra of M-type Stars with Homogeneous Atmospheric-Parameter Labels",
  "authors": [
    "Bing Du",
    "A-Li Luo",
    "Song Wang",
    "Yinbi Li",
    "Cai-Xia Qu",
    "Xiao Kong",
    "Yan-xin Guo",
    "Yi-han Song",
    "Fang Zuo"
  ],
  "comment": "28 pages, 23 figures, Journal",
  "categories": [
    "astro-ph.SR",
    "astro-ph.EP",
    "astro-ph.GA",
    "astro-ph.IM"
  ],
  "abstract": "The discrepancies between theoretical and observed spectra, and the systematic differences between various spectroscopic parameter estimates, complicate the determination of atmospheric parameters of M-type stars. In this work, we present an empirical sample of 5105 M-type star spectra with homogeneous atmospheric parameter labels through stellar-label transfer and sample cleaning. We addressed systematic discrepancies in spectroscopic parameter estimates by adopting recent results for Gaia EDR3 stars as a reference standard. Then, we used a density-based spatial clustering of applications with noise to remove unreliable samples in each subgrid of parameters. To confirm the reliability of the stellar labels, a 5-layer neural network was utilized, randomly partitioning the samples into training and testing sets. The standard deviations between the predicted and actual values in the testing set are 14 K for Teff , 0.06 dex for log g, and 0.05 dex for [M/H], respectively. In addition, we conducted an internal cross-validation to enhance validation and obtained precisions of 11 K, 0.05 dex, and 0.05 dex for Teff , log g, and [M/H], respectively. A grid of 1365 high Signal-to-Noise ratio (S/N) spectra and their labels, selected from the empirical sample, was utilized in the stellar parameter pipeline for M-Type stars (LASPM) of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), producing an almost seamless Kiel distribution diagram for LAMOST DR10 and DR11 data. The atmospheric parameters for M-type stars from LAMOST DR11 show improved precision compared to the data from DR9, with improvements (for spectra with S/N higher than 10) from 118 to 67 K in Teff , 0.2 to 0.07 dex in log g, and 0.29 to 0.14 dex in [M/H].",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-10-22T06:29:38.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "m-type star",
      "empirical sample",
      "homogeneous atmospheric-parameter labels",
      "multi-object fiber spectroscopic telescope",
      "area multi-object fiber spectroscopic"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 28,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}