{
  "id": "1902.10152",
  "version": "v1",
  "published": "2019-02-26T19:00:03.000Z",
  "updated": "2019-02-26T19:00:03.000Z",
  "title": "Dust extinction, dust emission, and dust temperature in galaxies at z>=5: a view from the FIRE-2 simulations",
  "authors": [
    "Xiangcheng Ma",
    "Christopher C. Hayward",
    "Caitlin M. Casey",
    "Philip F. Hopkins",
    "Eliot Quataert",
    "Lichen Liang",
    "Claude-André Faucher-Giguère",
    "Robert Feldmann",
    "Dušan Kereš"
  ],
  "comment": "21 pages, 17 figures, key results shown in Figs. 5, 8, 10, 11, submitted to MNRAS, comments welcome. Data products including mock galaxy SEDs and images are available upon request",
  "categories": [
    "astro-ph.GA",
    "astro-ph.CO"
  ],
  "abstract": "We present a suite of 34 high-resolution cosmological zoom-in simulations consisting of thousands of halos up to M_halo~10^12 M_sun (M_star~10^10.5 M_sun) at z>=5 from the Feedback in Realistic Environments project. We post-process our simulations with a three-dimensional Monte Carlo dust radiative transfer code to study dust extinction, dust emission, and dust temperature within these simulated z>=5 galaxies. Our sample forms a tight correlation between infrared excess (IRX=F_IR/F_UV) and ultraviolet (UV)-continuum slope (beta_UV), despite the patchy, clumpy dust geometry shown in our simulations. We find that the IRX-beta_UV relation is mainly determined by the shape of the extinction curve and is independent of its normalization (set by the dust-to-gas ratio). The bolometric IR luminosity (L_IR) correlates with the intrinsic UV luminosity and the star formation rate (SFR) averaged over the past 10 Myr. We predict that at a given L_IR, the peak wavelength of the dust spectral energy distributions for z>=5 galaxies is smaller by a factor of 2 (due to higher dust temperatures on average) than at z=0. The higher dust temperatures are driven by higher specific SFRs and SFR surface densities with increasing redshift. We derive the galaxy UV luminosity functions (LFs) at z=5-10 from our simulations and confirm that a heavy attenuation is required to reproduce the observed bright-end UVLFs. We also predict the IRLFs and UV luminosity densities at z=5-10. We discuss the implications of our results on current and future observations probing dust attenuation and emission in z>=5 galaxies.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-02-26T19:00:03.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "dust emission",
      "dust extinction",
      "dust radiative transfer code",
      "carlo dust radiative transfer",
      "uv luminosity"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 21,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}