{
  "id": "2308.05156",
  "version": "v1",
  "published": "2023-08-09T18:00:04.000Z",
  "updated": "2023-08-09T18:00:04.000Z",
  "title": "Discovery of a Split Stellar Stream In the Periphery of the Small Magellanic Cloud",
  "authors": [
    "David L. Nidever"
  ],
  "comment": "8 pages, 10 figures, 1 table. Submitted to MNRAS",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "I report the discovery of a stellar stream (Sutlej) using Gaia DR3 proper motions and XP metallicities located ~15 degrees north of the Small Magellanic Cloud (SMC). The stream is composed of two parallel linear components (\"branches\") approximately ~8 x 0.6 degrees in size and separated by 2.5 degrees. The stars have a mean proper motion of (pmra,pmdec)=(+0.08 mas/yr,-1.41 mas/yr) which is quite similar to the proper motion of stars on the western side of the SMC. The color magnitude diagram of the stream stars has a clear red giant branch, horizontal branch, and main sequence turnoff that is well-matched by a PARSEC isochrone of 10 Gyr, [Fe/H]=-1.8 at 32 kpc and a total stellar mass of ~33,000 Msun. The stream is spread out over an area of 9.6 square degrees and has a surface brightness of 32.5 mag/arcsec^2. The metallicity of the stream stars from Gaia XP spectra extend over -2.5 < [M/H] < -1.0 with a median of [M/H]=-1.8. The tangential velocity of the stream stars is 214 km/s compared to the values of 448 km/s for the Large Magellanic Cloud and 428 km/s for the SMC. While the radial velocity of the stream is not yet known, a comparison of the space velocities using a range of assumed radial velocities, shows that the stream is unlikely to be associated with the Magellanic Clouds. The tangential velocity vector is misaligned with the stream by ~25 degrees which might indicate an important gravitational influence from the nearby Magellanic Clouds.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-08-09T18:00:04.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "small magellanic cloud",
      "split stellar stream",
      "stream stars",
      "tangential velocity",
      "radial velocity"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 8,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}