{
  "id": "2108.13085",
  "version": "v1",
  "published": "2021-08-30T09:48:26.000Z",
  "updated": "2021-08-30T09:48:26.000Z",
  "title": "The diffuse interstellar band around 8620 Å II. Kinematics and distance of the DIB carrier",
  "authors": [
    "H. Zhao",
    "M. Schultheis",
    "A. Rojas-Arriagada",
    "A. Recio-Blanco",
    "P. de Laverny",
    "G. Kordopatis",
    "F. Surot"
  ],
  "comment": "12 pages, 12 figures, 2 tables, accepted by A&A",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We aim to make use of the measurements from the Giraffe Inner Bulge Survey (GIBS) and the Gaia$-$ESO survey (GES) to study the kinematics and distance of the carrier of DIB$\\,\\lambda$8620, as well as other properties. We successfully detected and measured DIB$\\,\\lambda$8620 in 760 of 4117 GES spectra. Combined with the DIBs measured in GIBS spectra, we confirmed a tight relation between EW and $E(J-K_{\\rm S})$ as well as $A_{\\rm V}$, with similar fitting coefficients to those found by previous works. With a more accurate sample and the consideration of the solar motion, the rest-frame wavelength of DIB$\\,\\lambda$8620 was redetermined as 8620.83 \\r{A}, with a mean fit error of 0.36 \\r{A}. We studied the kinematics of the DIB carriers by tracing their median radial velocities in each field in the local standard of rest ($V_{\\rm LSR}$) and into the galactocentric frame ($V_{\\rm GC}$), respectively, as a function of the Galactic longitudes. Based on the median $V_{\\rm LSR}$ and two Galactic rotation models, we obtained valid kinematic distances of the DIB carriers for nine GIBS and ten GES fields. We also found a linear relation between the DIB$\\,\\lambda$8620 measured in this work and the near-infrared DIB in APOGEE spectra at $1.5273\\,\\mu m$. We demonstrate that the DIB carriers can be located much closer to the observer than the background stars based on the following arguments: (i) qualitatively, the carriers occupy in the Galactic longitude$-$velocity diagram typical rotation velocities of stars in the local Galactic disk, while the background stars in the GIBS survey are mainly located in the Galactic bulge; (ii) quantitatively, all the derived kinematic distances of the DIB carriers are smaller than the median distances to background stars in each field.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-08-30T09:48:26.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "dib carrier",
      "diffuse interstellar band",
      "background stars",
      "giraffe inner bulge survey",
      "galactic longitude"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}