{
  "id": "1801.05808",
  "version": "v1",
  "published": "2018-01-17T19:00:01.000Z",
  "updated": "2018-01-17T19:00:01.000Z",
  "title": "Surface density: a new parameter in the fundamental metallicity relation of star-forming galaxies",
  "authors": [
    "Tetsuya Hashimoto",
    "Tomotsugu Goto",
    "Rieko Momose"
  ],
  "comment": "Published: 15 January 2018",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "Star-forming galaxies display a close relation among stellar mass, metallicity and star-formation rate (or molecular-gas mass). This is known as the fundamental metallicity relation (FMR) (or molecular-gas FMR), and it has a profound implication on models of galaxy evolution. However, there still remains a significant residual scatter around the FMR. We show here that a fourth parameter, the surface density of stellar mass, reduces the dispersion around the molecular-gas FMR. In a principal component analysis of 29 physical parameters of 41,338 star-forming galaxies, the surface density of stellar mass is found to be the fourth most important parameter. The new four-dimensional fundamental relation forms a tighter hypersurface that reduces the metallicity dispersion to 50\\% of that of the molecular-gas FMR. We suggest that future analyses and models of galaxy evolution should consider the FMR in a four-dimensional space that includes surface density. The dilution time scale of gas inflow and the star-formation efficiency could explain the observational dependence on surface density of stellar mass.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-01-17T19:00:01.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "surface density",
      "fundamental metallicity relation",
      "star-forming galaxies",
      "stellar mass",
      "molecular-gas fmr"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}