{
  "id": "2204.06398",
  "version": "v1",
  "published": "2022-04-13T14:01:11.000Z",
  "updated": "2022-04-13T14:01:11.000Z",
  "title": "Estimation of the Parameters of the Spiral Pattern in the Galaxy Based on a Sample of Classical Cepheids",
  "authors": [
    "V. V. Bobylev"
  ],
  "comment": "14 pages, 5 figures, 4 tables",
  "journal": "Astronomy Letters, 2022, Vol. 48, pp. 126-137",
  "doi": "10.1134/S1063773722010017",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We consider a sample of Galactic classical Cepheids with highly accurate estimates of their distances taken from Skowron et al., where they were determined based on the period-luminosity relation. We have refined the geometric characteristics of two spiral arm segments-the Carina-Sagittarius and Outer ones. For this purpose, we have selected 269 Cepheids belonging to the Carina-Sagittarius arm with ages in the range 80-120 Myr. From them we have estimated the pitch angle of the spiral pattern $i=-11.9\\pm0.2^\\circ$ and the position of this arm $a_0=7.32\\pm0.05$ kpc for the adopted $R_0=8.1\\pm0.1$ kpc. In the Outer arm we have selected 343 Cepheids with ages in the range 120-300 Myr. From them we have found $i=-11.5\\pm0.5^\\circ$ and $a_0=12.89\\pm0.06$ kpc. Adhering to the model of a grand-design spiral pattern in the Galaxy with one pitch angle for all arms, we can conclude that this angle is close to $-12^\\circ$.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-04-13T14:01:11.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "spiral pattern",
      "estimation",
      "spiral arm segments-the carina-sagittarius",
      "parameters",
      "pitch angle"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 14,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}