{
  "id": "1807.09714",
  "version": "v1",
  "published": "2018-07-25T16:40:20.000Z",
  "updated": "2018-07-25T16:40:20.000Z",
  "title": "Kinematics and physical properties of the nearby galaxy NGC 4656 and its TDG candidate",
  "authors": [
    "N. Muñoz-Elgueta",
    "S. Torres-Flores",
    "P. Amram",
    "J. A. Hernandez-Jimenez",
    "F. Urrutia-Viscarra",
    "C. Mendes de Oliveira",
    "J. A. Gómez-López"
  ],
  "comment": "23 pages, 18 figures. Accepted for publication in MNRAS",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "Interacting galaxies provide us with an excellent laboratory for studying a number of physical phenomena associated with these processes. In this paper, we present a spectroscopic and kinematic analysis of the interacting galaxy NGC 4656 and its companion Tidal Dwarf Galaxy (TDG) candidate, NGC 4656UV. Using Fabry-Perot and GMOS multi-slit data, we investigated the possible origin of NGC 4656UV. We found that NGC 4656UV has a low metallicity (12+log(O/H)$\\sim$8.2) and it follows the mass-metallicity relation (MZR) for normal dwarf galaxies. For NGC 4656, we estimated a flat oxygen abundance gradient of $\\beta$ = -0.027$\\pm$0.029 dex kpc$^{-1}$, which suggests the presence of gas flows induced by gravitational interactions. By analysing radial velocity profiles and by fitting a kinematic model of the observed velocity field, we confirm the literature result that NGC 4656 consists of one single body instead of two objects. We estimated a dynamical mass of $6.8^{1.8}_{-0.6}\\times10^{9}$ M$_{\\odot}$ and R of 12.1 kpc from the kinematic model of NGC 4656. Although the observed velocity field is dominated by rotation at large scales (V$_{max}$/$\\sigma\\gtrsim$2.8), important non-rotational motions are present at small scales. Based on these new results, and on previously published information, we propose that NGC 4656 and 4656UV are a pair of interacting galaxies. NGC 4656UV is a companion of NGC 4656 and it does not have a tidal origin. The interaction between the two could have triggered the star formation in NGC 4656UV and increased the star formation in the northeast side of NGC 4656.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-07-25T16:40:20.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "nearby galaxy ngc",
      "ngc 4656uv",
      "tdg candidate",
      "physical properties",
      "interacting galaxy"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 23,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}