---
res:
  bibo_abstract:
  - We present the first results from the X-SHOOTER Lyman α survey at z = 2 (XLS-z2).
    XLS-z2 is a deep spectroscopic survey of 35 Lyman α emitters (LAEs) utilizing
    ≈90 h of exposure time with Very Large Telescope/X-SHOOTER and covers rest-frame
    Ly α to H α emission with R ≈ 4000. We present the sample selection, the observations,
    and the data reduction. Systemic redshifts are measured from rest-frame optical
    lines for 33/35 sources. In the stacked spectrum, our LAEs are characterized by
    an interstellar medium with little dust, a low metallicity, and a high ionization
    state. The ionizing sources are young hot stars that power strong emission lines
    in the optical and high-ionization lines in the ultraviolet (UV). The LAEs exhibit
    clumpy UV morphologies and have outflowing kinematics with blueshifted Si II absorption,
    a broad [O III] component, and a red-skewed Ly α line. Typically, 30 per cent
    of the Ly α photons escape, of which one quarter on the blue side of the systemic
    velocity. A fraction of Ly α photons escape directly at the systemic suggesting
    clear channels enabling an ≈10 per cent escape of ionizing photons, consistent
    with an inference based on Mg II. A combination of a low effective H I column
    density, a low dust content, and young starburst determines whether a star-forming
    galaxy is observed as an LAE. The first is possibly related to outflows and/or
    a fortunate viewing angle, while we find that the latter two in LAEs are typical
    for their stellar mass of 109 M⊙.@eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Jorryt J
      foaf_name: Matthee, Jorryt J
      foaf_surname: Matthee
      foaf_workInfoHomepage: http://www.librecat.org/personId=7439a258-f3c0-11ec-9501-9df22fe06720
    orcid: 0000-0003-2871-127X
  - foaf_Person:
      foaf_givenName: David
      foaf_name: Sobral, David
      foaf_surname: Sobral
  - foaf_Person:
      foaf_givenName: Matthew
      foaf_name: Hayes, Matthew
      foaf_surname: Hayes
  - foaf_Person:
      foaf_givenName: Gabriele
      foaf_name: Pezzulli, Gabriele
      foaf_surname: Pezzulli
  - foaf_Person:
      foaf_givenName: Max
      foaf_name: Gronke, Max
      foaf_surname: Gronke
  - foaf_Person:
      foaf_givenName: Daniel
      foaf_name: Schaerer, Daniel
      foaf_surname: Schaerer
  - foaf_Person:
      foaf_givenName: Rohan P
      foaf_name: Naidu, Rohan P
      foaf_surname: Naidu
  - foaf_Person:
      foaf_givenName: Huub
      foaf_name: Röttgering, Huub
      foaf_surname: Röttgering
  - foaf_Person:
      foaf_givenName: João
      foaf_name: Calhau, João
      foaf_surname: Calhau
  - foaf_Person:
      foaf_givenName: Ana
      foaf_name: Paulino-Afonso, Ana
      foaf_surname: Paulino-Afonso
  - foaf_Person:
      foaf_givenName: Sérgio
      foaf_name: Santos, Sérgio
      foaf_surname: Santos
  - foaf_Person:
      foaf_givenName: Ricardo
      foaf_name: Amorín, Ricardo
      foaf_surname: Amorín
  bibo_doi: 10.1093/mnras/stab1304
  bibo_issue: '1'
  bibo_volume: 505
  dct_date: 2021^xs_gYear
  dct_isPartOf:
  - http://id.crossref.org/issn/0035-8711
  - http://id.crossref.org/issn/1365-2966
  dct_language: eng
  dct_publisher: Oxford University Press@
  dct_subject:
  - Space and Planetary Science
  - Astronomy and Astrophysics
  - 'galaxies: formation'
  - 'galaxies: ISM'
  - 'galaxies: starburst'
  - dark ages
  - reionization
  - first stars
  dct_title: 'The X-SHOOTER Lyman α survey at z = 2 (XLS-z2) I: What makes a galaxy
    a Lyman α emitter?@'
...