{
  "id": "1909.12558",
  "version": "v1",
  "published": "2019-09-27T08:42:33.000Z",
  "updated": "2019-09-27T08:42:33.000Z",
  "title": "Tracing Kinematic and Chemical Properties of Sagittarius Stream by K-Giants, M-Giants, and BHB stars",
  "authors": [
    "Chengqun Yang",
    "Xiang-Xiang Xue",
    "Jing Li",
    "Chao Liu",
    "Bo Zhang",
    "Hans-Walter Rix",
    "Lan Zhang",
    "Gang Zhao",
    "Hao Tian",
    "Jing Zhong",
    "Qianfan Xing",
    "Yaqian Wu",
    "Chengdong Li",
    "Jeffrey L. Carlin",
    "Jiang Chang"
  ],
  "comment": "26 pages, 15 figures",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We characterize the kinematic and chemical properties of $\\sim$3,000 Sagittarius (Sgr) stream stars, including K-giants, M-giants, and BHBs, select from SEGUE-2, LAMOST, and SDSS separately in Integrals-of-Motion space. The orbit of Sgr stream is quite clear from the velocity vector in $X$-$Z$ plane. Stars traced by K-giants and M-giants present the apogalacticon of trailing steam is $\\sim$ 100 kpc. The metallicity distributions of Sgr K-, M-giants, and BHBs present that the M-giants are on average the most metal-rich population, followed by K-giants and BHBs. All of the K-, M-giants, and BHBs indicate that the trailing arm is on average more metal-rich than leading arm, and the K-giants show that the Sgr debris is the most metal-poor part. The $\\alpha$-abundance of Sgr stars exhibits a similar trend with the Galactic halo stars at lower metallicity ([Fe/H] $<\\sim$ $-$1.0 dex), and then evolve down to lower [$\\alpha$/Fe] than disk stars at higher metallicity, which is close to the evolution pattern of $\\alpha$-element of Milky Way dwarf galaxies. We find $V_Y$ and metallicity of K-giants have gradients along the direction of line-of-sight from the Galactic center in $X$-$Z$ plane, and the K-giants show that $V_Y$ increases with metallicity at [Fe/H] $>\\sim-$1.5 dex. After dividing the Sgr stream into bright and faint stream according to their locations in equatorial coordinate, the K-giants and BHBs show that the bright and faint stream present different $V_Y$ and metallicities, the bright stream is on average higher in $V_Y$ and metallicity than the faint stream.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-09-27T08:42:33.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "chemical properties",
      "sagittarius stream",
      "bhb stars",
      "metallicity",
      "tracing kinematic"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 26,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}