{
  "id": "2307.09999",
  "version": "v1",
  "published": "2023-07-19T14:15:08.000Z",
  "updated": "2023-07-19T14:15:08.000Z",
  "title": "Searching for new globular clusters in M 31 with Gaia EDR3",
  "authors": [
    "Yilun Wang",
    "Haibo Yuan",
    "Bingqiu Chen",
    "Xinlei Chen",
    "Hao Wu",
    "Zexi Niu",
    "Jifeng Li"
  ],
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We found 50 new globular cluster (GC) candidates around M\\,31 with Gaia Early Data Release 3 (EDR3), with the help from Pan-STARRS1 DR1 magnitudes and Pan-Andromeda Archaeological Survey (PAndAS) images. Based on the latest Revised Bologna Catalog and \\textit{simbad}, we trained 2 Random Forest (RF) classifiers, the first one to distinguish extended sources from point sources and the second one to further select GCs from extended sources. From 1.85 million sources of $16^m{<}g{<}19.5^m$ and within a large area of $\\sim$392\\,deg$^2$ around M\\,31, we selected 20,658 extended sources and 1,934 initial GC candidates. After visual inspection of the PAndAS images to eliminate the contamination of non-cluster sources, particularly galaxies, we finally got 50 candidates. These candidates are divided into 3 types (\\textbf{a}, \\textbf{b}, \\textbf{c}) according to their projected distance $D$ to the center of M\\,31 and their probability to be a true GC, $P_{GC}$, which is calculated by our second RF classifier. Among these candidates, 14 are found to be associated (in projection) with the large-scale structures within the halo of M\\,31. We also provided several simple parameter criteria for selecting extended sources effectively from the Gaia EDR3, which can reach a completeness of 92.1\\% with a contamination fraction lower than 10\\%.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-07-19T14:15:08.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "gaia edr3",
      "globular cluster",
      "extended sources",
      "simple parameter criteria",
      "second rf classifier"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}