{
  "id": "2207.14303",
  "version": "v1",
  "published": "2022-07-28T18:00:00.000Z",
  "updated": "2022-07-28T18:00:00.000Z",
  "title": "Lyman-Alpha Escape from Low-Mass, Compact, High-Redshift Galaxies",
  "authors": [
    "Ragadeepika Pucha",
    "Naveen A. Reddy",
    "Arjun Dey",
    "Stéphanie Juneau",
    "Kyoung-Soo Lee",
    "Moire K. M. Prescott",
    "Irene Shivaei",
    "Sungryong Hong"
  ],
  "comment": "36 pages, 15 figures; Accepted for publication in The Astronomical Journal",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We investigate the effects of stellar populations and sizes on Ly$\\alpha$ escape in 27 spectroscopically confirmed and 35 photometric Lyman-Alpha Emitters (LAEs) at z $\\approx$ 2.65 in seven fields of the Bo\\\"otes region of the NOAO Deep Wide-Field Survey. We use deep $HST$/WFC3 imaging to supplement ground-based observations and infer key galaxy properties. Compared to typical star-forming galaxies (SFGs) at similar redshifts, the LAEs are less massive ($M_{\\star} \\approx 10^{7} - 10^{9}~M_{\\odot}$), younger (ages $\\lesssim$ 1 Gyr), smaller ($r_{e} <$ 1 kpc), less dust-attenuated (E(B$-$V) $\\le$ 0.26 mag), but have comparable star-formation-rates (SFRs $\\approx 1 - 100~M_{\\odot} {\\rm yr^{-1}}$). Some of the LAEs in the sample may be very young galaxies having low nebular metallicities (${\\rm Z_{neb} \\lesssim 0.2 Z_{\\odot}}$) and/or high ionization parameters ($\\log{(\\rm U)} \\gtrsim -2.4$). Motivated by previous studies, we examine the effects of the concentration of star formation and gravitational potential on Ly$\\alpha$ escape, by computing star-formation-rate surface density, $\\Sigma_{\\rm SFR}$ and specific star-formation-rate surface density, $\\Sigma_{\\rm sSFR}$. For a given $\\Sigma_{\\rm SFR}$, the Ly$\\alpha$ escape fraction is higher for LAEs with lower stellar masses. LAEs have higher $\\Sigma_{\\rm sSFR}$ on average compared to SFGs. Our results suggest that compact star formation in a low gravitational potential yields conditions amenable to the escape of Ly$\\alpha$ photons. These results have important implications for the physics of Ly$\\alpha$ radiative transfer and for the type of galaxies that may contribute significantly to cosmic reionization.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-07-28T18:00:00.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "high-redshift galaxies",
      "lyman-alpha escape",
      "potential yields conditions amenable",
      "low gravitational potential yields conditions",
      "specific star-formation-rate surface density"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 36,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}