---
_id: '11503'
abstract:
- lang: eng
  text: "Context. The Lyα emitter (LAE) fraction, XLAE, is a potentially powerful
    probe of the evolution of the intergalactic neutral hydrogen gas fraction. However,
    uncertainties in the measurement of XLAE are still under debate.\r\nAims. Thanks
    to deep data obtained with the integral field spectrograph Multi Unit Spectroscopic
    Explorer (MUSE), we can measure the evolution of the LAE fraction homogeneously
    over a wide redshift range of z ≈ 3–6 for UV-faint galaxies (down to UV magnitudes
    of M1500 ≈ −17.75). This is a significantly fainter range than in former studies
    (M1500 ≤ −18.75) and it allows us to probe the bulk of the population of high-redshift
    star-forming galaxies.\r\nMethods. We constructed a UV-complete photometric-redshift
    sample following UV luminosity functions and measured the Lyα emission with MUSE
    using the latest (second) data release from the MUSE Hubble Ultra Deep Field Survey.\r\nResults.
    We derived the redshift evolution of XLAE for M1500 ∈ [ − 21.75; −17.75] for the
    first time with a equivalent width range EW(Lyα) ≥ 65 Å and found low values of
    XLAE ≲ 30% at z ≲ 6. The best-fit linear relation is XLAE = 0.07+0.06−0.03z −
    0.22+0.12−0.24. For M1500 ∈ [ − 20.25; −18.75] and EW(Lyα) ≥ 25 Å, our XLAE values
    are consistent with those in the literature within 1σ at z ≲ 5, but our median
    values are systematically lower than reported values over the whole redshift range.
    In addition, we do not find a significant dependence of XLAE on M1500 for EW(Lyα)
    ≥ 50 Å at z ≈ 3–4, in contrast with previous work. The differences in XLAE mainly
    arise from selection biases for Lyman Break Galaxies (LBGs) in the literature:
    UV-faint LBGs are more easily selected if they have strong Lyα emission, hence
    XLAE is biased towards higher values when those samples are used.\r\nConclusions.
    Our results suggest either a lower increase of XLAE towards z ≈ 6 than previously
    suggested, or even a turnover of XLAE at z ≈ 5.5, which may be the signature of
    a late or patchy reionization process. We compared our results with predictions
    from a cosmological galaxy evolution model. We find that a model with a bursty
    star formation (SF) can reproduce our observed LAE fractions much better than
    models where SF is a smooth function of time."
acknowledgement: We thank the anonymous referee for constructive comments and suggestions.
  We would like to express our gratitude to Stephane De Barros and Pablo Arrabal Haro
  for kindly providing their data plotted in Figs. 1, 2, and 8. We are grateful to
  Kazuhiro Shimasaku, Masami Ouchi, Rieko Momose, Daniel Schaerer, Hidenobu Yajima,
  Taku Okamura, Makoto Ando, and Hinako Goto for giving insightful comments and suggestions.
  This work is based on observations taken by VLT, which is operated by European Southern
  Observatory. This research made use of Astropy (http://www.astropy.org), which is
  a community-developed core Python package for Astronomy (Astropy Collaboration 2013,
  2018), MARZ, MPDAF, and matplotlib (Hunter 2007). H.K. acknowledges support from
  Japan Society for the Promotion of Science (JSPS) through the JSPS Research Fellowship
  for Young Scientists and Overseas Challenge Program for Young Researchers. AV acknowledges
  support from the ERC starting grant 757258-TRIPLE and the SNF Professorship 176808-TRIPLE.
  This work was supported by the project FOGHAR (Agence Nationale de la Recherche,
  ANR-13-BS05-0010-02). JB acknowledges support from the ORAGE project from the Agence
  Nationale de la Recherche under grant ANR-14-CE33-0016-03. JR acknowledges support
  from the ERC starting grant 336736-CALENDS. T. H. acknowledges supports by the Grant-inAid
  for Scientic Research 19J01620.
article_number: A12
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Haruka
  full_name: Kusakabe, Haruka
  last_name: Kusakabe
- first_name: Jérémy
  full_name: Blaizot, Jérémy
  last_name: Blaizot
- first_name: Thibault
  full_name: Garel, Thibault
  last_name: Garel
- first_name: Anne
  full_name: Verhamme, Anne
  last_name: Verhamme
- first_name: Roland
  full_name: Bacon, Roland
  last_name: Bacon
- first_name: Johan
  full_name: Richard, Johan
  last_name: Richard
- first_name: Takuya
  full_name: Hashimoto, Takuya
  last_name: Hashimoto
- first_name: Hanae
  full_name: Inami, Hanae
  last_name: Inami
- first_name: Simon
  full_name: Conseil, Simon
  last_name: Conseil
- first_name: Bruno
  full_name: Guiderdoni, Bruno
  last_name: Guiderdoni
- first_name: Alyssa B.
  full_name: Drake, Alyssa B.
  last_name: Drake
- first_name: Edmund
  full_name: Christian Herenz, Edmund
  last_name: Christian Herenz
- first_name: Joop
  full_name: Schaye, Joop
  last_name: Schaye
- first_name: Pascal
  full_name: Oesch, Pascal
  last_name: Oesch
- 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: Raffaella
  full_name: Anna Marino, Raffaella
  last_name: Anna Marino
- first_name: Kasper
  full_name: Borello Schmidt, Kasper
  last_name: Borello Schmidt
- first_name: Roser
  full_name: Pelló, Roser
  last_name: Pelló
- first_name: Michael
  full_name: Maseda, Michael
  last_name: Maseda
- first_name: Floriane
  full_name: Leclercq, Floriane
  last_name: Leclercq
- first_name: Josephine
  full_name: Kerutt, Josephine
  last_name: Kerutt
- first_name: Guillaume
  full_name: Mahler, Guillaume
  last_name: Mahler
citation:
  ama: 'Kusakabe H, Blaizot J, Garel T, et al. The MUSE Hubble Ultra Deep Field Survey:
    XIV. Evolution of the Lyα emitter fraction from z = 3 to z = 6. <i>Astronomy &#38;
    Astrophysics</i>. 2020;638. doi:<a href="https://doi.org/10.1051/0004-6361/201937340">10.1051/0004-6361/201937340</a>'
  apa: 'Kusakabe, H., Blaizot, J., Garel, T., Verhamme, A., Bacon, R., Richard, J.,
    … Mahler, G. (2020). The MUSE Hubble Ultra Deep Field Survey: XIV. Evolution of
    the Lyα emitter fraction from z = 3 to z = 6. <i>Astronomy &#38; Astrophysics</i>.
    EDP Sciences. <a href="https://doi.org/10.1051/0004-6361/201937340">https://doi.org/10.1051/0004-6361/201937340</a>'
  chicago: 'Kusakabe, Haruka, Jérémy Blaizot, Thibault Garel, Anne Verhamme, Roland
    Bacon, Johan Richard, Takuya Hashimoto, et al. “The MUSE Hubble Ultra Deep Field
    Survey: XIV. Evolution of the Lyα Emitter Fraction from z = 3 to z = 6.” <i>Astronomy
    &#38; Astrophysics</i>. EDP Sciences, 2020. <a href="https://doi.org/10.1051/0004-6361/201937340">https://doi.org/10.1051/0004-6361/201937340</a>.'
  ieee: 'H. Kusakabe <i>et al.</i>, “The MUSE Hubble Ultra Deep Field Survey: XIV.
    Evolution of the Lyα emitter fraction from z = 3 to z = 6,” <i>Astronomy &#38;
    Astrophysics</i>, vol. 638. EDP Sciences, 2020.'
  ista: 'Kusakabe H, Blaizot J, Garel T, Verhamme A, Bacon R, Richard J, Hashimoto
    T, Inami H, Conseil S, Guiderdoni B, Drake AB, Christian Herenz E, Schaye J, Oesch
    P, Matthee JJ, Anna Marino R, Borello Schmidt K, Pelló R, Maseda M, Leclercq F,
    Kerutt J, Mahler G. 2020. The MUSE Hubble Ultra Deep Field Survey: XIV. Evolution
    of the Lyα emitter fraction from z = 3 to z = 6. Astronomy &#38; Astrophysics.
    638, A12.'
  mla: 'Kusakabe, Haruka, et al. “The MUSE Hubble Ultra Deep Field Survey: XIV. Evolution
    of the Lyα Emitter Fraction from z = 3 to z = 6.” <i>Astronomy &#38; Astrophysics</i>,
    vol. 638, A12, EDP Sciences, 2020, doi:<a href="https://doi.org/10.1051/0004-6361/201937340">10.1051/0004-6361/201937340</a>.'
  short: H. Kusakabe, J. Blaizot, T. Garel, A. Verhamme, R. Bacon, J. Richard, T.
    Hashimoto, H. Inami, S. Conseil, B. Guiderdoni, A.B. Drake, E. Christian Herenz,
    J. Schaye, P. Oesch, J.J. Matthee, R. Anna Marino, K. Borello Schmidt, R. Pelló,
    M. Maseda, F. Leclercq, J. Kerutt, G. Mahler, Astronomy &#38; Astrophysics 638
    (2020).
date_created: 2022-07-06T09:50:48Z
date_published: 2020-06-03T00:00:00Z
date_updated: 2022-07-19T09:35:20Z
day: '03'
doi: 10.1051/0004-6361/201937340
extern: '1'
external_id:
  arxiv:
  - '2003.12083'
intvolume: '       638'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'dark ages / reionization / first stars / early Universe / cosmology: observations
  / galaxies: evolution / galaxies: high-redshift / intergalactic medium'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/2003.12083
month: '06'
oa: 1
oa_version: Published Version
publication: Astronomy & Astrophysics
publication_identifier:
  eissn:
  - 1432-0746
  issn:
  - 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'The MUSE Hubble Ultra Deep Field Survey: XIV. Evolution of the Lyα emitter
  fraction from z = 3 to z = 6'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 638
year: '2020'
...
---
_id: '11541'
abstract:
- lang: eng
  text: We present new Hubble Space Telescope (HST)/WFC3 observations and re-analyse
    VLT data to unveil the continuum, variability, and rest-frame ultraviolet (UV)
    lines of the multiple UV clumps of the most luminous Lyα emitter at z = 6.6, CR7
    (COSMOS Redshift 7). Our re-reduced, flux-calibrated X-SHOOTER spectra of CR7
    reveal an He II emission line in observations obtained along the major axis of
    Lyα emission with the best seeing conditions. He II is spatially offset by ≈+0.8
    arcsec from the peak of Lyα emission, and it is found towards clump B. Our WFC3
    grism spectra detects the UV continuum of CR7’s clump A, yielding a power law
    with β=−2.5+0.6−0.7 and MUV=−21.87+0.25−0.20⁠. No significant variability is found
    for any of the UV clumps on their own, but there is tentative (≈2.2 σ) brightening
    of CR7 in F110W as a whole from 2012 to 2017. HST grism data fail to robustly
    detect rest-frame UV lines in any of the clumps, implying fluxes ≲2×10−17 erg s−1 cm−2
    (3σ). We perform CLOUDY modelling to constrain the metallicity and the ionizing
    nature of CR7. CR7 seems to be actively forming stars without any clear active
    galactic nucleus activity in clump A, consistent with a metallicity of ∼0.05–0.2 Z⊙.
    Component C or an interclump component between B and C may host a high ionization
    source. Our results highlight the need for spatially resolved information to study
    the formation and assembly of early galaxies.
acknowledgement: We thank the anonymous reviewer for the numerous detailed comments
  that led us to greatly improve the quality, extent, and statistical robustness of
  this work. DS acknowledges financial support from the Netherlands Organisation for
  Scientific research through a Veni fellowship. JM acknowledges the support of a
  Huygens PhD fellowship from Leiden University. AF acknowledges support from the
  ERC Advanced Grant INTERSTELLAR H2020/740120. BD acknowledges financial support
  from NASA through the Astrophysics Data Analysis Program, grant number NNX12AE20G
  and the National Science Foundation, grant number 1716907. We are thankful for several
  discussions and constructive comments from Johannes Zabl, Eros Vanzella, Bo Milvang-Jensen,
  Henry McCracken, Max Gronke, Mark Dijkstra, Richard Ellis, and Nicolas Laporte.
  We also thank Umar Burhanudin and Izzy Garland for taking part in the XGAL internship
  in Lancaster and for exploring the HST grism data independently. Based on observations
  obtained with HST/WFC3 programs 12578, 14495, and 14596. Based on observations of
  the National Japanese Observatory with the Suprime-Cam on the Subaru telescope (S14A-086)
  on the big island of Hawaii. This work is based in part on data products produced
  at TERAPIX available at the Canadian Astronomy Data Centre as part of the Canada–France–Hawaii
  Telescope Legacy Survey, a collaborative project of NRC and CNRS. Based on data
  products from observations made with ESO Telescopes at the La Silla Paranal Observatory
  under ESO programme IDs 294.A-5018, 294.A-5039, 092.A 0786, 093.A-0561, 097.A0043,
  097.A-0943, 098.A-0819, 298.A-5012, and 179.A-2005, and on data products produced
  by TERAPIX and the Cambridge Astronomy Survey Unit on behalf of the UltraVISTA consortium.
  The authors acknowledge the award of service time (SW2014b20) on the William Herschel
  Telescope (WHT). WHT and its service programme are operated on the island of La
  Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos
  of the Instituto de Astrofisica de Canarias. This research was supported by the
  Munich Institute for Astro- and Particle Physics of the DFG cluster of excellence
  ‘Origin and Structure of the Universe’. We have benefitted immensely from the public
  available programming language PYTHON, including NUMPY and SCIPY (Jones et al. 2001;
  Van Der Walt, Colbert & Varoquaux 2011), MATPLOTLIB (Hunter 2007), ASTROPY (Astropy
  Collaboration et al. 2013), and the TOPCAT analysis program (Taylor 2013). This
  research has made use of the VizieR catalogue access tool, CDS, Strasbourg, France.
  All data used for this paper are publicly available, and we make all reduced data
  available with the refereed paper.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: David
  full_name: Sobral, David
  last_name: Sobral
- 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: Gabriel
  full_name: Brammer, Gabriel
  last_name: Brammer
- first_name: Andrea
  full_name: Ferrara, Andrea
  last_name: Ferrara
- first_name: Lara
  full_name: Alegre, Lara
  last_name: Alegre
- first_name: Huub
  full_name: Röttgering, Huub
  last_name: Röttgering
- first_name: Daniel
  full_name: Schaerer, Daniel
  last_name: Schaerer
- first_name: Bahram
  full_name: Mobasher, Bahram
  last_name: Mobasher
- first_name: Behnam
  full_name: Darvish, Behnam
  last_name: Darvish
citation:
  ama: Sobral D, Matthee JJ, Brammer G, et al. On the nature and physical conditions
    of the luminous Ly α emitter CR7 and its rest-frame UV components. <i>Monthly
    Notices of the Royal Astronomical Society</i>. 2019;482(2):2422-2441. doi:<a href="https://doi.org/10.1093/mnras/sty2779">10.1093/mnras/sty2779</a>
  apa: Sobral, D., Matthee, J. J., Brammer, G., Ferrara, A., Alegre, L., Röttgering,
    H., … Darvish, B. (2019). On the nature and physical conditions of the luminous
    Ly α emitter CR7 and its rest-frame UV components. <i>Monthly Notices of the Royal
    Astronomical Society</i>. Oxford University Press. <a href="https://doi.org/10.1093/mnras/sty2779">https://doi.org/10.1093/mnras/sty2779</a>
  chicago: Sobral, David, Jorryt J Matthee, Gabriel Brammer, Andrea Ferrara, Lara
    Alegre, Huub Röttgering, Daniel Schaerer, Bahram Mobasher, and Behnam Darvish.
    “On the Nature and Physical Conditions of the Luminous Ly α Emitter CR7 and Its
    Rest-Frame UV Components.” <i>Monthly Notices of the Royal Astronomical Society</i>.
    Oxford University Press, 2019. <a href="https://doi.org/10.1093/mnras/sty2779">https://doi.org/10.1093/mnras/sty2779</a>.
  ieee: D. Sobral <i>et al.</i>, “On the nature and physical conditions of the luminous
    Ly α emitter CR7 and its rest-frame UV components,” <i>Monthly Notices of the
    Royal Astronomical Society</i>, vol. 482, no. 2. Oxford University Press, pp.
    2422–2441, 2019.
  ista: Sobral D, Matthee JJ, Brammer G, Ferrara A, Alegre L, Röttgering H, Schaerer
    D, Mobasher B, Darvish B. 2019. On the nature and physical conditions of the luminous
    Ly α emitter CR7 and its rest-frame UV components. Monthly Notices of the Royal
    Astronomical Society. 482(2), 2422–2441.
  mla: Sobral, David, et al. “On the Nature and Physical Conditions of the Luminous
    Ly α Emitter CR7 and Its Rest-Frame UV Components.” <i>Monthly Notices of the
    Royal Astronomical Society</i>, vol. 482, no. 2, Oxford University Press, 2019,
    pp. 2422–41, doi:<a href="https://doi.org/10.1093/mnras/sty2779">10.1093/mnras/sty2779</a>.
  short: D. Sobral, J.J. Matthee, G. Brammer, A. Ferrara, L. Alegre, H. Röttgering,
    D. Schaerer, B. Mobasher, B. Darvish, Monthly Notices of the Royal Astronomical
    Society 482 (2019) 2422–2441.
date_created: 2022-07-08T10:40:05Z
date_published: 2019-01-01T00:00:00Z
date_updated: 2022-08-19T06:49:36Z
day: '01'
doi: 10.1093/mnras/sty2779
extern: '1'
external_id:
  arxiv:
  - '1710.08422'
intvolume: '       482'
issue: '2'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'galaxies: evolution'
- 'galaxies: high-redshift'
- 'galaxies: ISM'
- 'cosmology: observations'
- dark ages
- reionization
- first stars
- early Universe
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1710.08422
month: '01'
oa: 1
oa_version: Preprint
page: 2422-2441
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: On the nature and physical conditions of the luminous Ly α emitter CR7 and
  its rest-frame UV components
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 482
year: '2019'
...
---
_id: '11519'
abstract:
- lang: eng
  text: 'Faint Lyα emitters become increasingly rarer toward the reionization epoch
    (z ∼ 6–7). However, observations from a very large (∼5 deg2) Lyα narrow-band survey
    at z = 6.6 show that this is not the case for the most luminous emitters, capable
    of ionizing their own local bubbles. Here we present follow-up observations of
    the two most luminous Lyα candidates in the COSMOS field: “MASOSA” and “CR7.”
    We used X-SHOOTER, SINFONI, and FORS2 on the Very Large Telescope, and DEIMOS
    on Keck, to confirm both candidates beyond any doubt. We find redshifts of z =
    6.541 and z = 6.604 for “MASOSA” and “CR7,” respectively. MASOSA has a strong
    detection in Lyα with a line width of 386 ± 30 km s−1 (FWHM) and with very high
    EW0 (>200 Å), but undetected in the continuum, implying very low stellar mass
    and a likely young, metal-poor stellar population. “CR7,” with an observed Lyα
    luminosity of 1043.92±0.05 erg s−1 is the most luminous Lyα emitter ever found
    at z > 6 and is spatially extended (∼16 kpc). “CR7” reveals a narrow Lyα line
    with 266 ± 15 km s−1 FWHM, being detected in the near-infrared (NIR) (rest-frame
    UV; β = −2.3 ± 0.1) and in IRAC/Spitzer. We detect a narrow He II 1640 Å emission
    line (6σ, FWHM = 130 ± 30 km s−1 ) in CR7 which can explain the clear excess seen
    in the J-band photometry (EW0 ∼ 80 Å). We find no other emission lines from the
    UV to the NIR in our X-SHOOTER spectra (He II/O III] 1663 Å > 3 and He II/C III]
    1908 Å > 2.5). We conclude that CR7 is best explained by a combination of a PopIII-like
    population, which dominates the rest-frame UV and the nebular emission, and a
    more normal stellar population, which presumably dominates the mass. Hubble Space
    Telescope/WFC3 observations show that the light is indeed spatially separated
    between a very blue component, coincident with Lyα and He II emission, and two
    red components (∼5 kpc away), which dominate the mass. Our findings are consistent
    with theoretical predictions of a PopIII wave, with PopIII star formation migrating
    away from the original sites of star formation.'
acknowledgement: We thank the anonymous reviewer for useful and constructive comments
  and suggestions which greatly improved the quality and clarity of our work. D.S.
  acknowledges financial support from the Netherlands Organisation for Scientific
  research (NWO) through a Veni fellowship, from FCT through a FCT Investigator Starting
  Grant and Start-up Grant (IF/01154/2012/CP0189/CT0010), from FCT grant UID/FIS/04434/2013,
  and from LSF and LKBF. J.M. acknowledges the award of a Huygens PhD fellowship.
  H.R. acknowledges support from the ERC Advanced Investigator program NewClusters
  321271. The authors thank Mark Dijkstra, Bhaskar Agarwal, Jarrett Johnson, Andrea
  Ferrara, Jarle Brinchmann, Rebecca Bowler, George Becker, Emma Curtis-Lake, Milos
  Milosavljevic, Raffaella Schneider, Paul Shapiro, and Erik Zackrisson for interesting,
  stimulating and helpful discussions. The authors are extremely grateful to ESO for
  the award of ESO DDT time (294.A-5018 and 294.A-5039) which allowed the spectroscopic
  confirmation of both sources and the detailed investigation of their nature. Observations
  are also based on data from W.M. Keck Observatory. The W.M. Keck Observatory is
  operated as a scientific partnership of Caltech, the University of California and
  the National Aeronautics and Space Administration. Based on observations obtained
  with MegaPrime/Megacam, a joint project of CFHT and CEA/IRFU, at the Canada–France–Hawaii
  Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada,
  the Institut National des Science de lUnivers of the Centre National de la Recherche
  Scientifique (CNRS) of France, and the University of Hawaii. This work is based
  in part on data products produced at Terapix available at the Canadian Astronomy
  Data Centre as part of the Canada–France–Hawaii Telescope Legacy Survey, a collaborative
  project of NRC and CNRS. Based on data products from observations made with ESO
  Telescopes at the La Silla Paranal Observatory under ESO programme IDs 294.A-5018,
  294.A-5039, and 179.A-2005, and on data products produced by TERAPIX and the Cambridge
  Astronomy Survey Unit on behalf of the UltraVISTA consortium. The authors acknowledge
  the award of service time (SW2014b20) on the William Herschel Telescope (WHT). WHT
  and its service programme are operated on the island of La Palma by the Isaac Newton
  Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de
  Astrofisica de Canarias.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: David
  full_name: Sobral, David
  last_name: Sobral
- 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: Behnam
  full_name: Darvish, Behnam
  last_name: Darvish
- first_name: Daniel
  full_name: Schaerer, Daniel
  last_name: Schaerer
- first_name: Bahram
  full_name: Mobasher, Bahram
  last_name: Mobasher
- first_name: Huub
  full_name: Röttgering, Huub
  last_name: Röttgering
- first_name: Sérgio
  full_name: Santos, Sérgio
  last_name: Santos
- first_name: Shoubaneh
  full_name: Hemmati, Shoubaneh
  last_name: Hemmati
citation:
  ama: 'Sobral D, Matthee JJ, Darvish B, et al. Evidence for PopIII-like stellar populations
    in the most luminous Lyα emitters at the epoch of reionisation: Spectroscopic
    confirmation. <i>The Astrophysical Journal</i>. 2015;808(2):139. doi:<a href="https://doi.org/10.1088/0004-637X/808/2/139">10.1088/0004-637X/808/2/139</a>'
  apa: 'Sobral, D., Matthee, J. J., Darvish, B., Schaerer, D., Mobasher, B., Röttgering,
    H., … Hemmati, S. (2015). Evidence for PopIII-like stellar populations in the
    most luminous Lyα emitters at the epoch of reionisation: Spectroscopic confirmation.
    <i>The Astrophysical Journal</i>. IOP Publishing. <a href="https://doi.org/10.1088/0004-637X/808/2/139">https://doi.org/10.1088/0004-637X/808/2/139</a>'
  chicago: 'Sobral, David, Jorryt J Matthee, Behnam Darvish, Daniel Schaerer, Bahram
    Mobasher, Huub Röttgering, Sérgio Santos, and Shoubaneh Hemmati. “Evidence for
    PopIII-like Stellar Populations in the Most Luminous Lyα Emitters at the Epoch
    of Reionisation: Spectroscopic Confirmation.” <i>The Astrophysical Journal</i>.
    IOP Publishing, 2015. <a href="https://doi.org/10.1088/0004-637X/808/2/139">https://doi.org/10.1088/0004-637X/808/2/139</a>.'
  ieee: 'D. Sobral <i>et al.</i>, “Evidence for PopIII-like stellar populations in
    the most luminous Lyα emitters at the epoch of reionisation: Spectroscopic confirmation,”
    <i>The Astrophysical Journal</i>, vol. 808, no. 2. IOP Publishing, p. 139, 2015.'
  ista: 'Sobral D, Matthee JJ, Darvish B, Schaerer D, Mobasher B, Röttgering H, Santos
    S, Hemmati S. 2015. Evidence for PopIII-like stellar populations in the most luminous
    Lyα emitters at the epoch of reionisation: Spectroscopic confirmation. The Astrophysical
    Journal. 808(2), 139.'
  mla: 'Sobral, David, et al. “Evidence for PopIII-like Stellar Populations in the
    Most Luminous Lyα Emitters at the Epoch of Reionisation: Spectroscopic Confirmation.”
    <i>The Astrophysical Journal</i>, vol. 808, no. 2, IOP Publishing, 2015, p. 139,
    doi:<a href="https://doi.org/10.1088/0004-637X/808/2/139">10.1088/0004-637X/808/2/139</a>.'
  short: D. Sobral, J.J. Matthee, B. Darvish, D. Schaerer, B. Mobasher, H. Röttgering,
    S. Santos, S. Hemmati, The Astrophysical Journal 808 (2015) 139.
date_created: 2022-07-07T09:00:58Z
date_published: 2015-07-28T00:00:00Z
date_updated: 2022-08-18T10:30:13Z
day: '28'
doi: 10.1088/0004-637X/808/2/139
extern: '1'
external_id:
  arxiv:
  - '1504.01734'
intvolume: '       808'
issue: '2'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- dark ages
- reionization
- 'first stars – early universe – galaxies: evolution'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1504.01734
month: '07'
oa: 1
oa_version: Preprint
page: '139'
publication: The Astrophysical Journal
publication_identifier:
  eissn:
  - 1538-4357
  issn:
  - 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Evidence for PopIII-like stellar populations in the most luminous Lyα emitters
  at the epoch of reionisation: Spectroscopic confirmation'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 808
year: '2015'
...
---
_id: '11580'
abstract:
- lang: eng
  text: 'We present results from the largest contiguous narrow-band survey in the
    near-infrared. We have used the wide-field infrared camera/Canada–France–Hawaii
    Telescope and the lowOH2 filter (1.187 ± 0.005 μm) to survey ≈10 deg2 of contiguous
    extragalactic sky in the SA22 field. A total of ∼6000 candidate emission-line
    galaxies are found. We use deep ugrizJK data to obtain robust photometric redshifts.
    We combine our data with the High-redshift(Z) Emission Line Survey (HiZELS), explore
    spectroscopic surveys (VVDS, VIPERS) and obtain our own spectroscopic follow-up
    with KMOS, FMOS and MOSFIRE to derive large samples of high-redshift emission-line
    selected galaxies: 3471 Hα emitters at z = 0.8, 1343 [O III] + Hβ emitters at
    z = 1.4 and 572 [O II] emitters at z = 2.2. We probe comoving volumes of >106
    Mpc3 and find significant overdensities, including an 8.5σ (spectroscopically
    confirmed) overdensity of Hα emitters at z = 0.81. We derive Hα, [O III] + Hβ
    and [O II] luminosity functions at z = 0.8, 1.4, 2.2, respectively, and present
    implications for future surveys such as Euclid. Our uniquely large volumes/areas
    allow us to subdivide the samples in thousands of randomized combinations of areas
    and provide a robust empirical measurement of sample/cosmic variance. We show
    that surveys for star-forming/emission-line galaxies at a depth similar to ours
    can only overcome cosmic-variance (errors <10 per cent) if they are based on volumes
    >5 × 105 Mpc3; errors on L* and ϕ* due to sample (cosmic) variance on surveys
    probing ∼104 and ∼105 Mpc3 are typically very high: ∼300 and ∼40–60 per cent,
    respectively.'
acknowledgement: The authors wish to thank the anonymous reviewer for many helpful
  comments and suggestions which greatly improved the clarity and quality of this
  work. DS acknowledges financial support from the Netherlands Organization for Scientific
  research (NWO) through a Veni fellowship, from FCT through an FCT Investigator Starting
  Grant and Start-up Grant (IF/01154/2012/CP0189/CT0010), from FCT grant PEst-OE/FIS/UI2751/2014,
  and from LSF and LKBF. JM acknowledges the award of a Huygens PhD fellowship. PNB
  is grateful for support from STFC. IRS acknowledges support from STFC, a Leverhulme
  Fellowship, the ERC Advanced Investigator programme DUSTYGAL and a Royal Society/Wolfson
  Merit Award. BMJ acknowledges support from the ERC-StG grant EGGS-278202. The Dark
  Cosmology Centre is funded by the DNRF. The Dark Cosmology Centre is funded by the
  DNRF. JWK acknowledges support from the National Research Foundation of Korea (NRF)
  grant, no. 2008-0060544, funded by the Korea government (MSIP). JPS acknowledges
  support from STFC (ST/I001573/1). JC acknowledges support from the FCT-IF grant
  IF/01154/2012/CP0189/CT0010. The work was only possible due to OPTICON/FP7 and the
  invaluable access that it granted to the CFHT telescope. We would also like to acknowledge
  the excellent work done by CFHT staff in conducting the observations in service
  mode, and on delivering truly excellent data. We are also tremendously thankful
  to Kentaro Aoki for the incredible support while observing at Subaru with FMOS,
  and also to the Keck staff for the help with the observations with MOSFIRE. This
  work is based on observations obtained with WIRCam on the CFHT, OPTICON programme
  2011B/029, 2012A019 and 2012B/016. Based on observations made with ESO telescopes
  at the La Silla Paranal Observatory under programmes IDs 60.A-9460 (data can be
  accessed through the ESO data archive), 087.A 0337 and 089.A-0965. Based on observations
  done with FMOS on Subaru under programme S14A-084, and on MOSFIRE/Keck observations
  under programme U066M. Part of the data on which this analysis is based are available
  from Sobral et al. (2013a). Dedicated to the memory of C. M. Sobral (1953-2014).
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: D.
  full_name: Sobral, D.
  last_name: Sobral
- 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: P. N.
  full_name: Best, P. N.
  last_name: Best
- first_name: I.
  full_name: Smail, I.
  last_name: Smail
- first_name: A. A.
  full_name: Khostovan, A. A.
  last_name: Khostovan
- first_name: B.
  full_name: Milvang-Jensen, B.
  last_name: Milvang-Jensen
- first_name: J.-W.
  full_name: Kim, J.-W.
  last_name: Kim
- first_name: J.
  full_name: Stott, J.
  last_name: Stott
- first_name: J.
  full_name: Calhau, J.
  last_name: Calhau
- first_name: H.
  full_name: Nayyeri, H.
  last_name: Nayyeri
- first_name: B.
  full_name: Mobasher, B.
  last_name: Mobasher
citation:
  ama: 'Sobral D, Matthee JJ, Best PN, et al. CF-HiZELS, an ∼10 deg2 emission-line
    survey with spectroscopic follow-up: Hα, [O III] + Hβ and [O II] luminosity functions
    at z = 0.8, 1.4 and 2.2 . <i>Monthly Notices of the Royal Astronomical Society</i>.
    2015;451(3):2303-2323. doi:<a href="https://doi.org/10.1093/mnras/stv1076">10.1093/mnras/stv1076</a>'
  apa: 'Sobral, D., Matthee, J. J., Best, P. N., Smail, I., Khostovan, A. A., Milvang-Jensen,
    B., … Mobasher, B. (2015). CF-HiZELS, an ∼10 deg2 emission-line survey with spectroscopic
    follow-up: Hα, [O III] + Hβ and [O II] luminosity functions at z = 0.8, 1.4 and
    2.2 . <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University
    Press. <a href="https://doi.org/10.1093/mnras/stv1076">https://doi.org/10.1093/mnras/stv1076</a>'
  chicago: 'Sobral, D., Jorryt J Matthee, P. N. Best, I. Smail, A. A. Khostovan, B.
    Milvang-Jensen, J.-W. Kim, et al. “CF-HiZELS, an ∼10 Deg2 Emission-Line Survey
    with Spectroscopic Follow-up: Hα, [O III] + Hβ and [O II] Luminosity Functions
    at z = 0.8, 1.4 and 2.2 .” <i>Monthly Notices of the Royal Astronomical Society</i>.
    Oxford University Press, 2015. <a href="https://doi.org/10.1093/mnras/stv1076">https://doi.org/10.1093/mnras/stv1076</a>.'
  ieee: 'D. Sobral <i>et al.</i>, “CF-HiZELS, an ∼10 deg2 emission-line survey with
    spectroscopic follow-up: Hα, [O III] + Hβ and [O II] luminosity functions at z
    = 0.8, 1.4 and 2.2 ,” <i>Monthly Notices of the Royal Astronomical Society</i>,
    vol. 451, no. 3. Oxford University Press, pp. 2303–2323, 2015.'
  ista: 'Sobral D, Matthee JJ, Best PN, Smail I, Khostovan AA, Milvang-Jensen B, Kim
    J-W, Stott J, Calhau J, Nayyeri H, Mobasher B. 2015. CF-HiZELS, an ∼10 deg2 emission-line
    survey with spectroscopic follow-up: Hα, [O III] + Hβ and [O II] luminosity functions
    at z = 0.8, 1.4 and 2.2 . Monthly Notices of the Royal Astronomical Society. 451(3),
    2303–2323.'
  mla: 'Sobral, D., et al. “CF-HiZELS, an ∼10 Deg2 Emission-Line Survey with Spectroscopic
    Follow-up: Hα, [O III] + Hβ and [O II] Luminosity Functions at z = 0.8, 1.4 and
    2.2 .” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 451, no.
    3, Oxford University Press, 2015, pp. 2303–23, doi:<a href="https://doi.org/10.1093/mnras/stv1076">10.1093/mnras/stv1076</a>.'
  short: D. Sobral, J.J. Matthee, P.N. Best, I. Smail, A.A. Khostovan, B. Milvang-Jensen,
    J.-W. Kim, J. Stott, J. Calhau, H. Nayyeri, B. Mobasher, Monthly Notices of the
    Royal Astronomical Society 451 (2015) 2303–2323.
date_created: 2022-07-14T09:02:22Z
date_published: 2015-08-11T00:00:00Z
date_updated: 2022-08-19T08:23:18Z
day: '11'
doi: 10.1093/mnras/stv1076
extern: '1'
external_id:
  arxiv:
  - '1502.06602'
intvolume: '       451'
issue: '3'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'galaxies: evolution'
- 'galaxies: formation'
- 'galaxies: luminosity function'
- mass function
- 'cosmology: observations'
- early Universe
- large-scale structure of Universe
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1502.06602
month: '08'
oa: 1
oa_version: Preprint
page: 2303-2323
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: 'CF-HiZELS, an ∼10 deg2 emission-line survey with spectroscopic follow-up:
  Hα, [O III] + Hβ and [O II] luminosity functions at z = 0.8, 1.4 and 2.2 '
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 451
year: '2015'
...
