{
  "id": "2210.09312",
  "version": "v1",
  "published": "2022-10-17T18:00:00.000Z",
  "updated": "2022-10-17T18:00:00.000Z",
  "title": "A new look at the infrared properties of z $\\sim$ 5 galaxies",
  "authors": [
    "L. Sommovigo",
    "A. Ferrara",
    "S. Carniani",
    "A. Pallottini",
    "P. Dayal",
    "E. Pizzati",
    "M. Ginolfi",
    "V. Markov",
    "A. Faisst"
  ],
  "comment": "Accepted for publication in MNRAS. 13 pages, 4 figures",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "Recent ALMA large surveys unveiled the presence of significant dust continuum emission in star-forming galaxies at $z>4$. Unfortunately, such large programs -- i.e. ALPINE ($z\\sim 5$) and REBELS ($z \\sim 7$) -- only provide us with a single Far-Infrared (FIR) continuum data point for their individual targets. Therefore, high-$z$ galaxies FIR spectral energy densities (SEDs) remain mostly unconstrained, hinging on an assumption for their dust temperature ($T_{\\rm d}$) in the SED fitting procedure. This introduces uncertainties in the inferred dust masses ($M_{\\rm d }$), infrared luminosities ($L_{\\rm IR}$), and obscured Star Formation Rate (SFR) fraction at $z > 4$. In this work we use a method that allows us to constrain $T_{\\rm d}$ with a single band measurement by combining the $158\\ \\mathrm{\\mu m}$ continuum information with the overlying [CII] emission line. We analyse the $21$ [CII] and FIR continuum detected $z\\sim 5$ galaxies in ALPINE, finding a range of $T_{\\rm d}=25-60\\ \\mathrm{K}$ and $M_{\\rm d} = 0.6-25.1\\ \\times 10^{7}\\ \\mathrm{M_{\\odot}}$. Given the measured stellar masses of ALPINE galaxies, the inferred dust yields are around $M_{\\rm d}/M_{\\star} = (0.2-8) \\times 10^{-3}$, consistent with theoretical dust-production constraints. We find that $8$ out of $21$ ALPINE galaxies have $L_{\\rm IR} \\geq 10^{12}\\ \\mathrm{L_{\\odot}}$, comparable to UltraLuminous IR Galaxies (ULIRGs). Relying on ultraviolet-to-optical SED fitting, the SFR was underestimated by up to $2$ orders of magnitude in $4$ of these $8$ ULIRGs-like galaxies. We conclude that these $4$ peculiar sources should be characterised by a two-phase interstellar medium structure with \"spatially-segregated\" FIR and ultraviolet emitting regions.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-10-17T18:00:00.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "infrared properties",
      "galaxies fir spectral energy densities",
      "significant dust continuum emission",
      "two-phase interstellar medium structure",
      "alpine galaxies"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 13,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}