{
  "id": "1602.08500",
  "version": "v1",
  "published": "2016-02-26T21:00:19.000Z",
  "updated": "2016-02-26T21:00:19.000Z",
  "title": "Morphological Classification of Local Luminous Infrared Galaxies",
  "authors": [
    "A. Psychogyios",
    "V. Charmandaris",
    "T. Diaz- Santos",
    "L. Armus",
    "S. Haan",
    "J. Howell",
    "E. Le Floc'h",
    "S. M. Petty",
    "A. S. Evans"
  ],
  "comment": "( 18 pages, 12 figures, Accepted for publication in A&A )",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We present an analysis of the morphological classification of 89 luminous infrared galaxies (LIRGs) from the Great Observatories All-sky LIRG Survey (GOALS) sample using non-parametric coefficients and compare their morphology as a function of wavelength. We rely on images obtained in the optical (B- and I-band) as well as in the infrared (H-band and 5.8$\\mu$m). Our classification is based on the calculation of $Gini$ and the second order of light ($M_{20}$) non-parametric coefficients which we explore as a function of stellar mass ($M_\\star$), infrared luminosity ($L_{IR}$) and star formation rate (SFR). We investigate the relation between $M_{20}$, the specific SFR (sSFR) and the dust temperature ($T_{dust}$) in our galaxy sample. We find that $M_{20}$ is a better morphological tracer than $Gini$, as it allows to distinguish systems formed by double systems from isolated and post-merger LIRGs. The multi-wavelength analysis allows us to identify a region in the $Gini$-$M_{20}$ parameter space where ongoing mergers reside, regardless of the band used to calculate the coefficients. In particular when measured in the H-band, this region can be used to identify ongoing mergers, with a minimal contamination from LIRGs in other stages. We also find that while the sSFR is positively correlated with $M_{20}$ when measured in the mid-infrared, i.e. star-bursting galaxies show more compact emission, it is anti-correlated with the B-band based $M_{20}$. We interpret this as the spatial decoupling between obscured and un-obscured star formation, whereby the ultraviolet/optical size of a LIRGs experience an intense dust enshrouded central starburst is larger than in the one in the mid-infrared since the contrast between the nuclear to the extended disk emission is smaller in the mid-infrared. This has important implications for high redshift surveys of dusty sources. [abridged]",
  "revisions": [
    {
      "version": "v1",
      "updated": "2016-02-26T21:00:19.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "local luminous infrared galaxies",
      "morphological classification",
      "great observatories all-sky lirg survey",
      "non-parametric coefficients",
      "star formation"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 18,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}