{
  "id": "1903.06185",
  "version": "v1",
  "published": "2019-03-14T18:00:45.000Z",
  "updated": "2019-03-14T18:00:45.000Z",
  "title": "Lyα emission from galaxies in the Epoch of Reionization",
  "authors": [
    "Christoph Behrens",
    "Andrea Pallottini",
    "Andrea Ferrara",
    "Simona Gallerani",
    "Livia Vallini"
  ],
  "comment": "submitted to MNRAS",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "The intrinsic strength of the Ly$\\alpha$ line in young, star-forming systems makes it a special tool for studying high-redshift galaxies. However, interpreting observations remains challenging due to the complex radiative transfer involved. Here, we combine state-of-the-art hydrodynamical simulations of 'Alth{\\ae}a', a prototypical Lyman Break Galaxy (LBG, stellar mass $M_{\\star}$$\\simeq$ $10^{10}{\\rm M}_{\\odot})$ at $z=7.2$, with detailed radiative transfer computations of dust/continuum, C[II] 158 $\\mu$m, and Ly$\\alpha$ to clarify the relation between the galaxy properties and its Ly$\\alpha$ emission. Alth{\\ae}a exhibits low ($f_\\alpha< 1$\\%) Ly$\\alpha$ escape fractions and Equivalent Widths, EW $\\lesssim 6$ Angstrom for the simulated lines of sight, with a large scatter. The correlation between escape fraction and inclination is weak, as a result of the rather chaotic structure of high-redshift galaxies. Low $f_\\alpha$ values persist even if we artificially remove neutral gas around star forming regions to mimick the presence of HII regions. The high attenuation is primarily caused by dust clumps co-located with young stellar clusters. We can turn Alth{\\ae}a into a Lyman Alpha Emitter (LAE) only if we artificially remove dust from the clumps, yielding EWs up to $22$ Angstrom. Our study suggests that the LBG-LAE duty-cycle required by recent clustering measurements poses the challenging problem of a dynamically changing dust attenuation. Finally, we find an anti-correlation between the magnitude of Ly$\\alpha$-C[II] line velocity shift and Ly$\\alpha$ luminosity.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-03-14T18:00:45.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "reionization",
      "prototypical lyman break galaxy",
      "studying high-redshift galaxies",
      "special tool",
      "state-of-the-art hydrodynamical simulations"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}