{
  "id": "2411.08958",
  "version": "v1",
  "published": "2024-11-13T19:00:04.000Z",
  "updated": "2024-11-13T19:00:04.000Z",
  "title": "Gas dynamics in an AGN-host galaxy at $z\\simeq2.6$: regular rotation, non-circular motions, and mass models",
  "authors": [
    "Lingrui Lin",
    "Federico Lelli",
    "Carlos De Breuck",
    "Allison Man",
    "Zhi-Yu Zhang",
    "Paola Santini",
    "Antonino Marasco",
    "Marco Castellano",
    "Nicole Nesvadba",
    "Thomas G. Bisbas",
    "Hao-Tse Huang",
    "Matthew Lehnert"
  ],
  "comment": "17 pages, 15 figures, 4 tables. Accepted for publication in Astronomy & Astrophysics. A companion paper (arXiv:2411.04290) is accepted in ApJ. Comments are welcome",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "The gas dynamics of galaxies provide critical insights into the evolution of both baryons and dark matter (DM) across cosmic time. In this context, galaxies at cosmic noon -- the period characterized by the most intense star formation and black hole activities -- are particularly significant. In this work, we present an analysis of the gas dynamics of PKS 0529-549: a galaxy at $z\\simeq2.6$, hosting a radio-loud active galactic nucleus (AGN). We use new ALMA observations of the [CI] (2-1) line at a spatial resolution of 0.18$''$ ($\\sim$1.5 kpc). We find that (1) the molecular gas forms a rotation-supported disk with $V_{\\rm rot}/\\sigma_{\\rm v}=6\\pm3$ and displays a flat rotation curve out to 3.3 kpc; (2) there are several non-circular components including a kinematically anomalous structure near the galaxy center, a gas tail to the South-West, and possibly a second weaker tail to the East; (3) dynamical estimates of gas and stellar masses from fitting the rotation curve are inconsistent with photometric estimates using standard gas conversion factors and stellar population models, respectively; these discrepancies may be due to systematic uncertainties in the photometric masses, in the dynamical masses, or in the case a more massive radio-loud AGN-host galaxy is hidden behind the gas-rich [CI] emitting starburst galaxy along the line of sight. Our work shows that in-depth investigations of 3D line cubes are crucial for revealing the complexity of gas dynamics in high-$z$ galaxies, in which regular rotation may coexist with non-circular motions and possibly tidal structures.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-11-13T19:00:04.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "gas dynamics",
      "regular rotation",
      "non-circular motions",
      "mass models",
      "rotation curve"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 17,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}