{
  "id": "2305.09714",
  "version": "v1",
  "published": "2023-05-16T18:00:01.000Z",
  "updated": "2023-05-16T18:00:01.000Z",
  "title": "An empirical study of dust properties at the earliest epochs",
  "authors": [
    "Joris Witstok",
    "Gareth C. Jones",
    "Roberto Maiolino",
    "Renske Smit",
    "Raffaella Schneider"
  ],
  "comment": "14 pages, 8 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Society",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We present an empirical analysis of the properties of dust-continuum emission in a sample of 17 galaxies in the early Universe ($4 < z < 8$) with well-sampled far-infrared (FIR) spectral energy distributions (SEDs) compiled from the literature. We place our results into context by self-consistently comparing to samples of nearby star-forming galaxies, luminous infrared galaxies (LIRGs), and quasars. With the exception of two sources, we find no significant evolution in the dust emissivity index across cosmic time, measuring a consistent value of $\\beta_\\text{IR} = 1.8 \\pm 0.3$ at $z > 4$, suggesting the effective dust properties do not change dramatically for most galaxies. Despite having comparable stellar masses, we find the high-redshift galaxies to be similar to, or even more extreme than, LIRGs in the HERUS sample in terms of dust temperature ($T_\\text{dust} > 40 \\, \\mathrm{K}$) and IR luminosity ($L_\\text{IR} > 10^{11} \\, \\mathrm{L_\\odot}$). We find the dust temperature evolves mildly towards high redshift, though the LIRGs and quasars exhibit elevated temperatures indicating a more efficient and/or additional heating mechanism. Where available, we compare stellar-mass estimates to our inferred dust masses, whose degeneracy with dust temperature can only be mitigated with a well-constrained SED. In merely half of the cases the dust yield may be explained by supernovae alone, with four sources ($44\\%$) significantly exceeding a highly optimistic yield where $M_\\text{dust} \\approx 0.01 M_*$. We discuss possible explanations for this apparent inconsistency and potential observational biases in the measurements of the dust properties of high-redshift galaxies, including in the current IR-bright sample.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-05-16T18:00:01.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "dust properties",
      "earliest epochs",
      "empirical study",
      "high-redshift galaxies",
      "dust temperature evolves"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 14,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}