---
_id: '11531'
abstract:
- lang: eng
  text: While low-luminosity galaxies dominate number counts at all redshifts, their
    contribution to cosmic reionization is poorly understood due to a lack of knowledge
    of their physical properties. We isolate a sample of 35 z ≈ 4–5 continuum-faint
    Lyman-α emitters from deep VLT/MUSE spectroscopy and directly measure their H α
    emission using stacked Spitzer/IRAC Ch. 1 photometry. Based on Hubble Space Telescope
    imaging, we determine that the average UV continuum magnitude is fainter than
    −16 (≈ 0.01 L⋆), implying a median Lyman-α equivalent width of 259 Å. By combining
    the H α measurement with the UV magnitude, we determine the ionizing photon production
    efficiency, ξion, a first for such faint galaxies. The measurement of log10 (ξion
    [Hz erg−1]) = 26.28 (⁠+0.28−0.40⁠) is in excess of literature measurements of
    both continuum- and emission line-selected samples, implying a more efficient
    production of ionizing photons in these lower luminosity, Lyman-α-selected systems.
    We conclude that this elevated efficiency can be explained by stellar populations
    with metallicities between 4 × 10−4 and 0.008, with light-weighted ages less than
    3 Myr.
acknowledgement: 'We would like to thank the anonymous referee for a thoughtful report
  and suggestions that have improved this manuscript. We are also grateful to everyone
  involved in the Spitzer Space Telescope mission and everyone at the Spitzer Science
  Center: we are truly fortunate to have been able to use data from this facility.
  J. B. acknowledges support by FCT/MCTES through national funds by this grant UID/FIS/04434/2019
  and through the Investigador FCT contract no. IF/01654/2014/CP1215/CT0003. S. C.
  gratefully acknowledges support from Swiss National Science Foundation grant PP00P2
  163824. We would also like to thank Mauro Stefanon for his assistance with de-blending
  the IRAC photometry, Pieter van Dokkum for a number of useful suggestions, and Daniel
  Schaerer for information regarding the stellar population models. This study is
  based on observations made with ESO telescopes at the La Silla Paranal Observatory
  under programs IDs 094.A-2089(B), 095.A0010(A), 096.A-0045(A), and 096.A-0045(B).'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Michael V
  full_name: Maseda, Michael V
  last_name: Maseda
- first_name: Roland
  full_name: Bacon, Roland
  last_name: Bacon
- first_name: Daniel
  full_name: Lam, Daniel
  last_name: Lam
- first_name: Jorryt J
  full_name: Matthee, Jorryt J
  id: 7439a258-f3c0-11ec-9501-9df22fe06720
  last_name: Matthee
  orcid: 0000-0003-2871-127X
- first_name: Jarle
  full_name: Brinchmann, Jarle
  last_name: Brinchmann
- first_name: Joop
  full_name: Schaye, Joop
  last_name: Schaye
- first_name: Ivo
  full_name: Labbe, Ivo
  last_name: Labbe
- first_name: Kasper B
  full_name: Schmidt, Kasper B
  last_name: Schmidt
- first_name: Leindert
  full_name: Boogaard, Leindert
  last_name: Boogaard
- first_name: Rychard
  full_name: Bouwens, Rychard
  last_name: Bouwens
- first_name: Sebastiano
  full_name: Cantalupo, Sebastiano
  last_name: Cantalupo
- first_name: Marijn
  full_name: Franx, Marijn
  last_name: Franx
- first_name: Takuya
  full_name: Hashimoto, Takuya
  last_name: Hashimoto
- first_name: Hanae
  full_name: Inami, Hanae
  last_name: Inami
- first_name: Haruka
  full_name: Kusakabe, Haruka
  last_name: Kusakabe
- first_name: Guillaume
  full_name: Mahler, Guillaume
  last_name: Mahler
- first_name: Themiya
  full_name: Nanayakkara, Themiya
  last_name: Nanayakkara
- first_name: Johan
  full_name: Richard, Johan
  last_name: Richard
- first_name: Lutz
  full_name: Wisotzki, Lutz
  last_name: Wisotzki
citation:
  ama: Maseda MV, Bacon R, Lam D, et al. Elevated ionizing photon production efficiency
    in faint high-equivalent-width Lyman-α emitters. <i>Monthly Notices of the Royal
    Astronomical Society</i>. 2020;493(4):5120-5130. doi:<a href="https://doi.org/10.1093/mnras/staa622">10.1093/mnras/staa622</a>
  apa: Maseda, M. V., Bacon, R., Lam, D., Matthee, J. J., Brinchmann, J., Schaye,
    J., … Wisotzki, L. (2020). Elevated ionizing photon production efficiency in faint
    high-equivalent-width Lyman-α emitters. <i>Monthly Notices of the Royal Astronomical
    Society</i>. Oxford University Press. <a href="https://doi.org/10.1093/mnras/staa622">https://doi.org/10.1093/mnras/staa622</a>
  chicago: Maseda, Michael V, Roland Bacon, Daniel Lam, Jorryt J Matthee, Jarle Brinchmann,
    Joop Schaye, Ivo Labbe, et al. “Elevated Ionizing Photon Production Efficiency
    in Faint High-Equivalent-Width Lyman-α Emitters.” <i>Monthly Notices of the Royal
    Astronomical Society</i>. Oxford University Press, 2020. <a href="https://doi.org/10.1093/mnras/staa622">https://doi.org/10.1093/mnras/staa622</a>.
  ieee: M. V. Maseda <i>et al.</i>, “Elevated ionizing photon production efficiency
    in faint high-equivalent-width Lyman-α emitters,” <i>Monthly Notices of the Royal
    Astronomical Society</i>, vol. 493, no. 4. Oxford University Press, pp. 5120–5130,
    2020.
  ista: Maseda MV, Bacon R, Lam D, Matthee JJ, Brinchmann J, Schaye J, Labbe I, Schmidt
    KB, Boogaard L, Bouwens R, Cantalupo S, Franx M, Hashimoto T, Inami H, Kusakabe
    H, Mahler G, Nanayakkara T, Richard J, Wisotzki L. 2020. Elevated ionizing photon
    production efficiency in faint high-equivalent-width Lyman-α emitters. Monthly
    Notices of the Royal Astronomical Society. 493(4), 5120–5130.
  mla: Maseda, Michael V., et al. “Elevated Ionizing Photon Production Efficiency
    in Faint High-Equivalent-Width Lyman-α Emitters.” <i>Monthly Notices of the Royal
    Astronomical Society</i>, vol. 493, no. 4, Oxford University Press, 2020, pp.
    5120–30, doi:<a href="https://doi.org/10.1093/mnras/staa622">10.1093/mnras/staa622</a>.
  short: M.V. Maseda, R. Bacon, D. Lam, J.J. Matthee, J. Brinchmann, J. Schaye, I.
    Labbe, K.B. Schmidt, L. Boogaard, R. Bouwens, S. Cantalupo, M. Franx, T. Hashimoto,
    H. Inami, H. Kusakabe, G. Mahler, T. Nanayakkara, J. Richard, L. Wisotzki, Monthly
    Notices of the Royal Astronomical Society 493 (2020) 5120–5130.
date_created: 2022-07-07T10:46:41Z
date_published: 2020-04-01T00:00:00Z
date_updated: 2022-08-18T11:23:27Z
day: '01'
doi: 10.1093/mnras/staa622
extern: '1'
external_id:
  arxiv:
  - '2002.11117'
fulldoi: https://doi.org/10.1093/mnras/staa622
intvolume: '       493'
issue: '4'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'Galaxies: evolution'
- 'Galaxies: high-redshift'
- 'Galaxies: ISM'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1093/mnras/staa622
month: '04'
oa: 1
oa_version: Published Version
page: 5120-5130
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
  eissn:
  - 1365-2966
  issn:
  - 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: Elevated ionizing photon production efficiency in faint high-equivalent-width
  Lyman-α emitters
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 493
year: '2020'
...