[{"date_created":"2022-07-07T09:21:30Z","language":[{"iso":"eng"}],"publisher":"Oxford University Press","scopus_import":"1","date_published":"2022-06-01T00:00:00Z","article_type":"original","month":"06","page":"5960-5977","issue":"4","publication":"Monthly Notices of the Royal Astronomical Society","status":"public","intvolume":"       512","type":"journal_article","day":"01","main_file_link":[{"url":"https://arxiv.org/abs/2110.11967","open_access":"1"}],"title":"(Re)Solving reionization with Lyα: How bright Lyα emitters account for the z ≈ 2 − 8 cosmic ionizing background","external_id":{"arxiv":["2110.11967"]},"doi":"10.1093/mnras/stac801","year":"2022","acknowledgement":"We thank an anonymous referee for an encouraging and constructive report that helped improving the quality of this work. We acknowledge illuminating conversations with Xiaohan Wu, Chris Cain, Anna-Christina Eilers, Simon Lilly and Ruari Mackenzie. RPN gratefully acknowledges an Ashford Fellowship granted by Harvard University. MG was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51409. PO acknowledges support from the Swiss National Science Foundation through the SNSF Professorship grant 190079. GP acknowledges support from the Netherlands Research School for Astronomy (NOVA). MH is fellow of the Knut and Alice Wallenberg Foundation. DE is supported by the US National Science Foundation (NSF) through Astronomy & Astrophysics grant AST-1909198. The Cosmic Dawn Center (DAWN) is funded by the Danish National Research Foundation under grant No. 140. RA acknowledges support from Fondecyt Regular Grant 1202007. ST is supported by the 2021 Research Fund 1.210134.01 of UNIST (Ulsan National Institute of Science & Technology). MLl acknowledges support from the ANID/Scholarship Program/Doctorado Nacional/2019-21191036. JC acknowledges support from the Spanish Ministry of Science and Innovation, project PID2019-107408GB-C43 (ESTALLIDOS) and from Gobierno de Canarias through EU FEDER funding, project PID2020010050.","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa_version":"Preprint","quality_controlled":"1","_id":"11521","publication_identifier":{"issn":["0035-8711"],"eissn":["1365-2966"]},"extern":"1","volume":512,"oa":1,"date_updated":"2022-08-18T10:42:47Z","article_processing_charge":"No","arxiv":1,"author":[{"first_name":"Jorryt J","full_name":"Matthee, Jorryt J","last_name":"Matthee","orcid":"0000-0003-2871-127X","id":"7439a258-f3c0-11ec-9501-9df22fe06720"},{"first_name":"Rohan P.","last_name":"Naidu","full_name":"Naidu, Rohan P."},{"last_name":"Pezzulli","full_name":"Pezzulli, Gabriele","first_name":"Gabriele"},{"full_name":"Gronke, Max","last_name":"Gronke","first_name":"Max"},{"last_name":"Sobral","full_name":"Sobral, David","first_name":"David"},{"last_name":"Oesch","full_name":"Oesch, Pascal A.","first_name":"Pascal A."},{"full_name":"Hayes, Matthew","last_name":"Hayes","first_name":"Matthew"},{"full_name":"Erb, Dawn","last_name":"Erb","first_name":"Dawn"},{"last_name":"Schaerer","full_name":"Schaerer, Daniel","first_name":"Daniel"},{"first_name":"Ricardo","full_name":"Amorín, Ricardo","last_name":"Amorín"},{"first_name":"Sandro","full_name":"Tacchella, Sandro","last_name":"Tacchella"},{"first_name":"Ana Paulino-Afonso","last_name":"Ana Paulino-Afonso","full_name":"Ana Paulino-Afonso, Ana Paulino-Afonso"},{"full_name":"Llerena, Mario","last_name":"Llerena","first_name":"Mario"},{"first_name":"João","full_name":"Calhau, João","last_name":"Calhau"},{"last_name":"Röttgering","full_name":"Röttgering, Huub","first_name":"Huub"}],"keyword":["galaxies: high-redshift","intergalactic medium","cosmology: observations","dark ages","reionization","first stars","ultraviolet: galaxies"],"abstract":[{"text":"The cosmic ionizing emissivity from star-forming galaxies has long been anchored to UV luminosity functions. Here, we introduce an emissivity framework based on Lyα emitters (LAEs), which naturally hones in on the subset of galaxies responsible for the ionizing background due to the intimate connection between production and escape of Lyα and LyC photons. Using constraints on the escape fractions of bright LAEs (LLyα > 0.2L*) at z ≈ 2 obtained from resolved Lyα profiles, and arguing for their redshift-invariance, we show that: (i) quasars and LAEs together reproduce the relatively flat emissivity at z ≈ 2–6, which is non-trivial given the strong evolution in both the star formation density and quasar number density at these epochs and (ii) LAEs produce late and rapid reionization between z ≈ 6−9 under plausible assumptions. Within this framework, the >10 × rise in the UV population-averaged fesc between z ≈ 3–7 naturally arises due to the same phenomena that drive the growing LAE fraction with redshift. Generally, a LAE dominated emissivity yields a peak in the distribution of the ionizing budget with UV luminosity as reported in latest simulations. Using our adopted parameters (⁠fesc=50 per cent⁠, ξion = 1025.9 Hz erg−1 for half the bright LAEs), a highly ionizing minority of galaxies with MUV < −17 accounts for the entire ionizing budget from star-forming galaxies. Rapid flashes of LyC from such rare galaxies produce a ‘disco’ ionizing background. We conclude proposing tests to further develop our suggested Lyα-anchored formalism.","lang":"eng"}],"publication_status":"published","citation":{"chicago":"Matthee, Jorryt J, Rohan P. Naidu, Gabriele Pezzulli, Max Gronke, David Sobral, Pascal A. Oesch, Matthew Hayes, et al. “(Re)Solving Reionization with Lyα: How Bright Lyα Emitters Account for the z ≈ 2 − 8 Cosmic Ionizing Background.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2022. <a href=\"https://doi.org/10.1093/mnras/stac801\">https://doi.org/10.1093/mnras/stac801</a>.","ieee":"J. J. Matthee <i>et al.</i>, “(Re)Solving reionization with Lyα: How bright Lyα emitters account for the z ≈ 2 − 8 cosmic ionizing background,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 512, no. 4. Oxford University Press, pp. 5960–5977, 2022.","apa":"Matthee, J. J., Naidu, R. P., Pezzulli, G., Gronke, M., Sobral, D., Oesch, P. A., … Röttgering, H. (2022). (Re)Solving reionization with Lyα: How bright Lyα emitters account for the z ≈ 2 − 8 cosmic ionizing background. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/stac801\">https://doi.org/10.1093/mnras/stac801</a>","short":"J.J. Matthee, R.P. Naidu, G. Pezzulli, M. Gronke, D. Sobral, P.A. Oesch, M. Hayes, D. Erb, D. Schaerer, R. Amorín, S. Tacchella, A.P.-A. Ana Paulino-Afonso, M. Llerena, J. Calhau, H. Röttgering, Monthly Notices of the Royal Astronomical Society 512 (2022) 5960–5977.","ista":"Matthee JJ, Naidu RP, Pezzulli G, Gronke M, Sobral D, Oesch PA, Hayes M, Erb D, Schaerer D, Amorín R, Tacchella S, Ana Paulino-Afonso AP-A, Llerena M, Calhau J, Röttgering H. 2022. (Re)Solving reionization with Lyα: How bright Lyα emitters account for the z ≈ 2 − 8 cosmic ionizing background. Monthly Notices of the Royal Astronomical Society. 512(4), 5960–5977.","mla":"Matthee, Jorryt J., et al. “(Re)Solving Reionization with Lyα: How Bright Lyα Emitters Account for the z ≈ 2 − 8 Cosmic Ionizing Background.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 512, no. 4, Oxford University Press, 2022, pp. 5960–77, doi:<a href=\"https://doi.org/10.1093/mnras/stac801\">10.1093/mnras/stac801</a>.","ama":"Matthee JJ, Naidu RP, Pezzulli G, et al. (Re)Solving reionization with Lyα: How bright Lyα emitters account for the z ≈ 2 − 8 cosmic ionizing background. <i>Monthly Notices of the Royal Astronomical Society</i>. 2022;512(4):5960-5977. doi:<a href=\"https://doi.org/10.1093/mnras/stac801\">10.1093/mnras/stac801</a>"}},{"type":"journal_article","day":"01","status":"public","intvolume":"       508","page":"3697-3709","issue":"3","publication":"Monthly Notices of the Royal Astronomical Society","date_published":"2021-12-01T00:00:00Z","article_type":"original","month":"12","language":[{"iso":"eng"}],"publisher":"Oxford University Press","scopus_import":"1","date_created":"2022-07-07T09:30:21Z","publication_status":"published","citation":{"apa":"Gronke, M., Ocvirk, P., Mason, C., Matthee, J. J., Bosman, S. E. I., Sorce, J. G., … Yepes, G. (2021). Lyman-α transmission properties of the intergalactic medium in the CoDaII simulation. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/stab2762\">https://doi.org/10.1093/mnras/stab2762</a>","ieee":"M. Gronke <i>et al.</i>, “Lyman-α transmission properties of the intergalactic medium in the CoDaII simulation,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 508, no. 3. Oxford University Press, pp. 3697–3709, 2021.","chicago":"Gronke, Max, Pierre Ocvirk, Charlotte Mason, Jorryt J Matthee, Sarah E I Bosman, Jenny G Sorce, Joseph Lewis, et al. “Lyman-α Transmission Properties of the Intergalactic Medium in the CoDaII Simulation.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2021. <a href=\"https://doi.org/10.1093/mnras/stab2762\">https://doi.org/10.1093/mnras/stab2762</a>.","mla":"Gronke, Max, et al. “Lyman-α Transmission Properties of the Intergalactic Medium in the CoDaII Simulation.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 508, no. 3, Oxford University Press, 2021, pp. 3697–709, doi:<a href=\"https://doi.org/10.1093/mnras/stab2762\">10.1093/mnras/stab2762</a>.","ama":"Gronke M, Ocvirk P, Mason C, et al. Lyman-α transmission properties of the intergalactic medium in the CoDaII simulation. <i>Monthly Notices of the Royal Astronomical Society</i>. 2021;508(3):3697-3709. doi:<a href=\"https://doi.org/10.1093/mnras/stab2762\">10.1093/mnras/stab2762</a>","short":"M. Gronke, P. Ocvirk, C. Mason, J.J. Matthee, S.E.I. Bosman, J.G. Sorce, J. Lewis, K. Ahn, D. Aubert, T. Dawoodbhoy, I.T. Iliev, P.R. Shapiro, G. Yepes, Monthly Notices of the Royal Astronomical Society 508 (2021) 3697–3709.","ista":"Gronke M, Ocvirk P, Mason C, Matthee JJ, Bosman SEI, Sorce JG, Lewis J, Ahn K, Aubert D, Dawoodbhoy T, Iliev IT, Shapiro PR, Yepes G. 2021. Lyman-α transmission properties of the intergalactic medium in the CoDaII simulation. Monthly Notices of the Royal Astronomical Society. 508(3), 3697–3709."},"keyword":["dark ages","reionization","first stars","intergalactic medium","galaxies: formation"],"author":[{"first_name":"Max","full_name":"Gronke, Max","last_name":"Gronke"},{"last_name":"Ocvirk","full_name":"Ocvirk, Pierre","first_name":"Pierre"},{"first_name":"Charlotte","full_name":"Mason, Charlotte","last_name":"Mason"},{"last_name":"Matthee","full_name":"Matthee, Jorryt J","orcid":"0000-0003-2871-127X","first_name":"Jorryt J","id":"7439a258-f3c0-11ec-9501-9df22fe06720"},{"full_name":"Bosman, Sarah E I","last_name":"Bosman","first_name":"Sarah E I"},{"full_name":"Sorce, Jenny G","last_name":"Sorce","first_name":"Jenny G"},{"first_name":"Joseph","last_name":"Lewis","full_name":"Lewis, Joseph"},{"full_name":"Ahn, Kyungjin","last_name":"Ahn","first_name":"Kyungjin"},{"first_name":"Dominique","full_name":"Aubert, Dominique","last_name":"Aubert"},{"last_name":"Dawoodbhoy","full_name":"Dawoodbhoy, Taha","first_name":"Taha"},{"first_name":"Ilian T","last_name":"Iliev","full_name":"Iliev, Ilian T"},{"first_name":"Paul R","last_name":"Shapiro","full_name":"Shapiro, Paul R"},{"last_name":"Yepes","full_name":"Yepes, Gustavo","first_name":"Gustavo"}],"abstract":[{"lang":"eng","text":"The decline in abundance of Lyman-α (Lyα) emitting galaxies at z ≳ 6 is a powerful and commonly used probe to constrain the progress of cosmic reionization. We use the CODAII simulation, which is a radiation hydrodynamic simulation featuring a box of ∼94 comoving Mpc side length, to compute the Lyα transmission properties of the intergalactic medium (IGM) at z ∼ 5.8 to 7. Our results mainly confirm previous studies, i.e. we find a declining Lyα transmission with redshift and a large sightline-to-sightline variation. However, motivated by the recent discovery of blue Lyα peaks at high redshift, we also analyse the IGM transmission on the blue side, which shows a rapid decline at z ≳ 6 of the blue transmission. This low transmission can be attributed not only to the presence of neutral regions but also to the residual neutral hydrogen within ionized regions, for which a density even as low as nHI∼10−9cm−3 (sometimes combined with kinematic effects) leads to a significantly reduced visibility. Still, we find that ∼1 per cent of sightlines towards M1600AB ∼ −21 galaxies at z ∼ 7 are transparent enough to allow a transmission of a blue Lyα peak. We discuss our results in the context of the interpretation of observations."}],"oa":1,"date_updated":"2022-08-18T10:45:56Z","volume":508,"article_processing_charge":"No","arxiv":1,"acknowledgement":"The authors thank the referee for constructive feedback that improved the outcome of this study. We are grateful to Antoinette Songaila Cowie for sharing the ‘NEPLA4’ spectrum with us. This research has made use of NASA’s Astrophysics Data System, and many open source projects such as trident (Hummels et al. 2017), IPython (Pérez & Granger 2007), SciPy (Virtanen et al. 2019), NumPy (Walt et al. 2011), matplotlib (Hunter 2007), pandas (McKinney 2010), and the yt-project (Turk et al. 2011). MG was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51409 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. MG acknowledges support from NASA grants HST-GO-15643.017, and HST-AR15797.001 as well as XSEDE grant TG-AST180036. CAM acknowledges support by NASA Headquarters through the NASA Hubble Fellowship grant HST-HF2-51413.001-A. PRS was supported in part by U.S. NSF grant AST-1009799, NASA grant NNX11AE09G, and supercomputer resources from NSF XSEDE grant TG AST090005 and the Texas Advanced Computing Center (TACC) at The University of Texas at Austin. JM acknowledges a Zwicky Prize Fellowship from ETH Zurich. GY acknowledges financial support by MICIU/FEDER under project grant PGC2018-094975-C21. SEIB acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 669253). ITI was supported by the Science and Technology Facilities Council [grants ST/I000976/1, ST/F002858/1, ST/P000525/1, and ST/T000473/1]; and The Southeast Physics Network (SEPNet). KA was supported by NRF2016R1D1A1B04935414 and NRF-2016R1A5A1013277. KA also appreciates APCTP for its hospitality during completion of this work. PO acknowledges support from the French ANR funded project ORAGE (ANR-14-CE33-0016). ND and DA acknowledge funding from the French ANR for project ANR-12-JS05- 0001 (EMMA). The CoDa II simulation was performed at Oak Ridge National Laboratory/Oak Ridge Leadership Computing Facility on the Titan supercomputer (INCITE 2016 award AST031). Processing was performed on the Eos and Rhea clusters. Resolution study simulations were performed on Piz Daint at the Swiss National Supercomputing Center (PRACE Tier 0 award, project id pr37). The authors would like to acknowledge the High Performance Computing center of the University of Strasbourg for supporting this work by providing scientific support and access to computing resources. Part of the computing resources were funded by the Equipex EquipMeso project (Programme Investissements d’Avenir) and the CPER Alsacalcul/Big Data.","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","quality_controlled":"1","oa_version":"Preprint","_id":"11522","extern":"1","publication_identifier":{"issn":["0035-8711"],"eissn":["1365-2966"]},"doi":"10.1093/mnras/stab2762","year":"2021","external_id":{"arxiv":["2004.14496"]},"title":"Lyman-α transmission properties of the intergalactic medium in the CoDaII simulation","main_file_link":[{"url":"https://arxiv.org/abs/2004.14496","open_access":"1"}]},{"language":[{"iso":"eng"}],"scopus_import":"1","publisher":"Oxford University Press","date_published":"2021-07-01T00:00:00Z","article_type":"original","month":"07","date_created":"2022-07-07T09:33:39Z","status":"public","intvolume":"       505","type":"journal_article","day":"01","page":"1382-1412","publication":"Monthly Notices of the Royal Astronomical Society","issue":"1","external_id":{"arxiv":["2102.07779"]},"title":"The X-SHOOTER Lyman α survey at z = 2 (XLS-z2) I: What makes a galaxy a Lyman α emitter?","doi":"10.1093/mnras/stab1304","year":"2021","main_file_link":[{"url":"https://arxiv.org/abs/2102.07779","open_access":"1"}],"keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: formation","galaxies: ISM","galaxies: starburst","dark ages","reionization","first stars"],"author":[{"last_name":"Matthee","full_name":"Matthee, Jorryt J","orcid":"0000-0003-2871-127X","first_name":"Jorryt J","id":"7439a258-f3c0-11ec-9501-9df22fe06720"},{"full_name":"Sobral, David","last_name":"Sobral","first_name":"David"},{"first_name":"Matthew","last_name":"Hayes","full_name":"Hayes, Matthew"},{"first_name":"Gabriele","full_name":"Pezzulli, Gabriele","last_name":"Pezzulli"},{"full_name":"Gronke, Max","last_name":"Gronke","first_name":"Max"},{"first_name":"Daniel","full_name":"Schaerer, Daniel","last_name":"Schaerer"},{"last_name":"Naidu","full_name":"Naidu, Rohan P","first_name":"Rohan P"},{"last_name":"Röttgering","full_name":"Röttgering, Huub","first_name":"Huub"},{"full_name":"Calhau, João","last_name":"Calhau","first_name":"João"},{"full_name":"Paulino-Afonso, Ana","last_name":"Paulino-Afonso","first_name":"Ana"},{"full_name":"Santos, Sérgio","last_name":"Santos","first_name":"Sérgio"},{"first_name":"Ricardo","full_name":"Amorín, Ricardo","last_name":"Amorín"}],"abstract":[{"text":"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⊙.","lang":"eng"}],"citation":{"chicago":"Matthee, Jorryt J, David Sobral, Matthew Hayes, Gabriele Pezzulli, Max Gronke, Daniel Schaerer, Rohan P Naidu, et al. “The X-SHOOTER Lyman α Survey at z = 2 (XLS-Z2) I: What Makes a Galaxy a Lyman α Emitter?” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2021. <a href=\"https://doi.org/10.1093/mnras/stab1304\">https://doi.org/10.1093/mnras/stab1304</a>.","apa":"Matthee, J. J., Sobral, D., Hayes, M., Pezzulli, G., Gronke, M., Schaerer, D., … Amorín, R. (2021). The X-SHOOTER Lyman α survey at z = 2 (XLS-z2) I: What makes a galaxy a Lyman α emitter? <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/stab1304\">https://doi.org/10.1093/mnras/stab1304</a>","ieee":"J. J. Matthee <i>et al.</i>, “The X-SHOOTER Lyman α survey at z = 2 (XLS-z2) I: What makes a galaxy a Lyman α emitter?,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 505, no. 1. Oxford University Press, pp. 1382–1412, 2021.","short":"J.J. Matthee, D. Sobral, M. Hayes, G. Pezzulli, M. Gronke, D. Schaerer, R.P. Naidu, H. Röttgering, J. Calhau, A. Paulino-Afonso, S. Santos, R. Amorín, Monthly Notices of the Royal Astronomical Society 505 (2021) 1382–1412.","ista":"Matthee JJ, Sobral D, Hayes M, Pezzulli G, Gronke M, Schaerer D, Naidu RP, Röttgering H, Calhau J, Paulino-Afonso A, Santos S, Amorín R. 2021. The X-SHOOTER Lyman α survey at z = 2 (XLS-z2) I: What makes a galaxy a Lyman α emitter? Monthly Notices of the Royal Astronomical Society. 505(1), 1382–1412.","ama":"Matthee JJ, Sobral D, Hayes M, et al. The X-SHOOTER Lyman α survey at z = 2 (XLS-z2) I: What makes a galaxy a Lyman α emitter? <i>Monthly Notices of the Royal Astronomical Society</i>. 2021;505(1):1382-1412. doi:<a href=\"https://doi.org/10.1093/mnras/stab1304\">10.1093/mnras/stab1304</a>","mla":"Matthee, Jorryt J., et al. “The X-SHOOTER Lyman α Survey at z = 2 (XLS-Z2) I: What Makes a Galaxy a Lyman α Emitter?” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 505, no. 1, Oxford University Press, 2021, pp. 1382–412, doi:<a href=\"https://doi.org/10.1093/mnras/stab1304\">10.1093/mnras/stab1304</a>."},"publication_status":"published","oa_version":"Preprint","quality_controlled":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","acknowledgement":"We thank the referee for constructive comments and suggestions. We thank Dawn Erb, Ruari Mackenzie, Ivan Oteo, Ryan Sanders, and Johannes Zabl for useful discussions and suggestions. It is a pleasure to thank the ESO User Support, in particular Giacomo Beccari, Carlo Manara, John Pritchard, Marina Rejkuba, and Lowell Tacconi-Garman for assistance in the preparation and execution of the observations. Based on observations obtained with the VLT, programs 084.A-0303, 088.A-0672, 091.A-0413, 091.A-0546, 092.A0774, 097.A-0153, 098.A-0819, 099.A-0758, 099.A-0254, 101.B0779, and 102.A-0652. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under ESO programme ID 179.A-2005 and on data products produced by CALET and the Cambridge Astronomy Survey Unit on behalf of the UltraVISTA consortium. Based on observations made with the NASA/ESA HST through programs 9133, 9367, 11694, and 12471, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESA), and the Canadian Astronomy Data Centre (CADC/NRC/CSA). This work is based on observations taken by the CANDELS Multi-Cycle Treasury Program with the NASA/ESA HST, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. MG was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51409 and acknowledges support from HST grants\r\nHST-GO-15643.017-A, HST-AR-15039.003-A, and XSEDE grant TG-AST180036. GP acknowledges support from the Netherlands Research School for Astronomy (NOVA). RA acknowledges the support of ANID FONDECYT Regular Grant 1202007. We gratefully acknowledge the PYTHON programming language, its NUMPY, MATPLOTLIB, SCIPY, LMFIT (Jones et al. 2001; Hunter 2007; van der Walt, Colbert & Varoquaux 2011), PANDAS (McKinney 2010), and ASTROPY (Astropy Collaboration 2013) packages, and the TOPCAT analysis tool (Taylor 2013). Dedicated to the memory of A. C. J.Matthee (1953–2020).","publication_identifier":{"eissn":["1365-2966"],"issn":["0035-8711"]},"extern":"1","_id":"11523","article_processing_charge":"No","date_updated":"2022-08-18T10:49:00Z","oa":1,"volume":505,"arxiv":1},{"date_created":"2022-07-06T09:50:48Z","month":"06","article_type":"original","date_published":"2020-06-03T00:00:00Z","scopus_import":"1","publisher":"EDP Sciences","language":[{"iso":"eng"}],"publication":"Astronomy & Astrophysics","day":"03","type":"journal_article","intvolume":"       638","status":"public","article_number":"A12","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/2003.12083"}],"doi":"10.1051/0004-6361/201937340","year":"2020","title":"The MUSE Hubble Ultra Deep Field Survey: XIV. Evolution of the Lyα emitter fraction from z = 3 to z = 6","external_id":{"arxiv":["2003.12083"]},"arxiv":1,"article_processing_charge":"No","date_updated":"2022-07-19T09:35:20Z","volume":638,"oa":1,"publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"extern":"1","_id":"11503","oa_version":"Published Version","quality_controlled":"1","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.","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","citation":{"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.","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).","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>.","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>","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.","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>"},"publication_status":"published","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."}],"keyword":["Space and Planetary Science","Astronomy and Astrophysics","dark ages / reionization / first stars / early Universe / cosmology: observations / galaxies: evolution / galaxies: high-redshift / intergalactic medium"],"author":[{"last_name":"Kusakabe","full_name":"Kusakabe, Haruka","first_name":"Haruka"},{"first_name":"Jérémy","full_name":"Blaizot, Jérémy","last_name":"Blaizot"},{"first_name":"Thibault","full_name":"Garel, Thibault","last_name":"Garel"},{"last_name":"Verhamme","full_name":"Verhamme, Anne","first_name":"Anne"},{"first_name":"Roland","full_name":"Bacon, Roland","last_name":"Bacon"},{"full_name":"Richard, Johan","last_name":"Richard","first_name":"Johan"},{"last_name":"Hashimoto","full_name":"Hashimoto, Takuya","first_name":"Takuya"},{"first_name":"Hanae","full_name":"Inami, Hanae","last_name":"Inami"},{"last_name":"Conseil","full_name":"Conseil, Simon","first_name":"Simon"},{"full_name":"Guiderdoni, Bruno","last_name":"Guiderdoni","first_name":"Bruno"},{"first_name":"Alyssa B.","full_name":"Drake, Alyssa B.","last_name":"Drake"},{"full_name":"Christian Herenz, Edmund","last_name":"Christian Herenz","first_name":"Edmund"},{"full_name":"Schaye, Joop","last_name":"Schaye","first_name":"Joop"},{"full_name":"Oesch, Pascal","last_name":"Oesch","first_name":"Pascal"},{"first_name":"Jorryt J","last_name":"Matthee","full_name":"Matthee, Jorryt J","orcid":"0000-0003-2871-127X","id":"7439a258-f3c0-11ec-9501-9df22fe06720"},{"first_name":"Raffaella","full_name":"Anna Marino, Raffaella","last_name":"Anna Marino"},{"first_name":"Kasper","last_name":"Borello Schmidt","full_name":"Borello Schmidt, Kasper"},{"last_name":"Pelló","full_name":"Pelló, Roser","first_name":"Roser"},{"first_name":"Michael","full_name":"Maseda, Michael","last_name":"Maseda"},{"first_name":"Floriane","full_name":"Leclercq, Floriane","last_name":"Leclercq"},{"last_name":"Kerutt","full_name":"Kerutt, Josephine","first_name":"Josephine"},{"first_name":"Guillaume","full_name":"Mahler, Guillaume","last_name":"Mahler"}]},{"year":"2020","doi":"10.1093/mnras/staa2550","external_id":{"arxiv":["2008.01731"]},"title":"The nature of CR7 revealed with MUSE: A young starburst powering extended Ly α emission at z = 6.6","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/2008.01731"}],"publication_status":"published","citation":{"mla":"Matthee, Jorryt J., et al. “The Nature of CR7 Revealed with MUSE: A Young Starburst Powering Extended Ly α Emission at z = 6.6.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 498, no. 2, Oxford University Press, 2020, pp. 3043–59, doi:<a href=\"https://doi.org/10.1093/mnras/staa2550\">10.1093/mnras/staa2550</a>.","ama":"Matthee JJ, Pezzulli G, Mackenzie R, et al. The nature of CR7 revealed with MUSE: A young starburst powering extended Ly α emission at z = 6.6. <i>Monthly Notices of the Royal Astronomical Society</i>. 2020;498(2):3043-3059. doi:<a href=\"https://doi.org/10.1093/mnras/staa2550\">10.1093/mnras/staa2550</a>","short":"J.J. Matthee, G. Pezzulli, R. Mackenzie, S. Cantalupo, H. Kusakabe, F. Leclercq, D. Sobral, J. Richard, L. Wisotzki, S. Lilly, L. Boogaard, R. Marino, M. Maseda, T. Nanayakkara, Monthly Notices of the Royal Astronomical Society 498 (2020) 3043–3059.","ista":"Matthee JJ, Pezzulli G, Mackenzie R, Cantalupo S, Kusakabe H, Leclercq F, Sobral D, Richard J, Wisotzki L, Lilly S, Boogaard L, Marino R, Maseda M, Nanayakkara T. 2020. The nature of CR7 revealed with MUSE: A young starburst powering extended Ly α emission at z = 6.6. Monthly Notices of the Royal Astronomical Society. 498(2), 3043–3059.","apa":"Matthee, J. J., Pezzulli, G., Mackenzie, R., Cantalupo, S., Kusakabe, H., Leclercq, F., … Nanayakkara, T. (2020). The nature of CR7 revealed with MUSE: A young starburst powering extended Ly α emission at z = 6.6. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/staa2550\">https://doi.org/10.1093/mnras/staa2550</a>","ieee":"J. J. Matthee <i>et al.</i>, “The nature of CR7 revealed with MUSE: A young starburst powering extended Ly α emission at z = 6.6,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 498, no. 2. Oxford University Press, pp. 3043–3059, 2020.","chicago":"Matthee, Jorryt J, Gabriele Pezzulli, Ruari Mackenzie, Sebastiano Cantalupo, Haruka Kusakabe, Floriane Leclercq, David Sobral, et al. “The Nature of CR7 Revealed with MUSE: A Young Starburst Powering Extended Ly α Emission at z = 6.6.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2020. <a href=\"https://doi.org/10.1093/mnras/staa2550\">https://doi.org/10.1093/mnras/staa2550</a>."},"abstract":[{"lang":"eng","text":"CR7 is among the most luminous Ly α emitters (LAEs) known at z = 6.6 and consists of at least three UV components that are surrounded by Ly α emission. Previous studies have suggested that it may host an extreme ionizing source. Here, we present deep integral field spectroscopy of CR7 with VLT/Multi Unit Spectroscopic Explorer (MUSE). We measure extended emission with a similar halo scale length as typical LAEs at z ≈ 5. CR7’s Ly α halo is clearly elongated along the direction connecting the multiple components, likely tracing the underlying gas distribution. The Ly α emission originates almost exclusively from the brightest UV component, but we also identify a faint kinematically distinct Ly α emitting region nearby a fainter component. Combined with new near-infrared data, the MUSE data show that the rest-frame Ly α equivalent width (EW) is ≈100 Å. This is a factor 4 higher than the EW measured in low-redshift analogues with carefully matched Ly α profiles (and thus arguably H I column density), but this EW can plausibly be explained by star formation. Alternative scenarios requiring active galactic nucleus (AGN) powering are also disfavoured by the narrower and steeper Ly α spectrum and much smaller IR to UV ratio compared to obscured AGN in other Ly α blobs. CR7’s Ly α emission, while extremely luminous, resembles the emission in more common LAEs at lower redshifts very well and is likely powered by a young metal-poor starburst."}],"author":[{"id":"7439a258-f3c0-11ec-9501-9df22fe06720","first_name":"Jorryt J","full_name":"Matthee, Jorryt J","last_name":"Matthee","orcid":"0000-0003-2871-127X"},{"first_name":"Gabriele","full_name":"Pezzulli, Gabriele","last_name":"Pezzulli"},{"full_name":"Mackenzie, Ruari","last_name":"Mackenzie","first_name":"Ruari"},{"first_name":"Sebastiano","full_name":"Cantalupo, Sebastiano","last_name":"Cantalupo"},{"first_name":"Haruka","last_name":"Kusakabe","full_name":"Kusakabe, Haruka"},{"first_name":"Floriane","full_name":"Leclercq, Floriane","last_name":"Leclercq"},{"first_name":"David","full_name":"Sobral, David","last_name":"Sobral"},{"full_name":"Richard, Johan","last_name":"Richard","first_name":"Johan"},{"last_name":"Wisotzki","full_name":"Wisotzki, Lutz","first_name":"Lutz"},{"full_name":"Lilly, Simon","last_name":"Lilly","first_name":"Simon"},{"first_name":"Leindert","last_name":"Boogaard","full_name":"Boogaard, Leindert"},{"full_name":"Marino, Raffaella","last_name":"Marino","first_name":"Raffaella"},{"last_name":"Maseda","full_name":"Maseda, Michael","first_name":"Michael"},{"last_name":"Nanayakkara","full_name":"Nanayakkara, Themiya","first_name":"Themiya"}],"keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: evolution","galaxies: high-redshift","dark ages","reionization","first stars","cosmology: observations"],"arxiv":1,"date_updated":"2022-08-18T11:04:05Z","volume":498,"oa":1,"article_processing_charge":"No","_id":"11529","publication_identifier":{"issn":["0035-8711"],"eissn":["1365-2966"]},"extern":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","quality_controlled":"1","oa_version":"Preprint","month":"10","date_published":"2020-10-01T00:00:00Z","article_type":"original","publisher":"Oxford University Press","scopus_import":"1","language":[{"iso":"eng"}],"date_created":"2022-07-07T10:36:01Z","day":"01","type":"journal_article","intvolume":"       498","status":"public","issue":"2","publication":"Monthly Notices of the Royal Astronomical Society","page":"3043-3059"},{"doi":"10.1093/mnras/stz3554","year":"2020","title":"Resolved Lyman-α properties of a luminous Lyman-break galaxy in a large ionized bubble at z = 6.53 ","external_id":{"arxiv":["1909.06376"]},"main_file_link":[{"url":"https://arxiv.org/abs/1909.06376","open_access":"1"}],"citation":{"mla":"Matthee, Jorryt J., et al. “Resolved Lyman-α Properties of a Luminous Lyman-Break Galaxy in a Large Ionized Bubble at z = 6.53 .” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 492, no. 2, Oxford University Press, 2020, pp. 1778–90, doi:<a href=\"https://doi.org/10.1093/mnras/stz3554\">10.1093/mnras/stz3554</a>.","ama":"Matthee JJ, Sobral D, Gronke M, et al. Resolved Lyman-α properties of a luminous Lyman-break galaxy in a large ionized bubble at z = 6.53 . <i>Monthly Notices of the Royal Astronomical Society</i>. 2020;492(2):1778-1790. doi:<a href=\"https://doi.org/10.1093/mnras/stz3554\">10.1093/mnras/stz3554</a>","ista":"Matthee JJ, Sobral D, Gronke M, Pezzulli G, Cantalupo S, Röttgering H, Darvish B, Santos S. 2020. Resolved Lyman-α properties of a luminous Lyman-break galaxy in a large ionized bubble at z = 6.53 . Monthly Notices of the Royal Astronomical Society. 492(2), 1778–1790.","short":"J.J. Matthee, D. Sobral, M. Gronke, G. Pezzulli, S. Cantalupo, H. Röttgering, B. Darvish, S. Santos, Monthly Notices of the Royal Astronomical Society 492 (2020) 1778–1790.","ieee":"J. J. Matthee <i>et al.</i>, “Resolved Lyman-α properties of a luminous Lyman-break galaxy in a large ionized bubble at z = 6.53 ,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 492, no. 2. Oxford University Press, pp. 1778–1790, 2020.","apa":"Matthee, J. J., Sobral, D., Gronke, M., Pezzulli, G., Cantalupo, S., Röttgering, H., … Santos, S. (2020). Resolved Lyman-α properties of a luminous Lyman-break galaxy in a large ionized bubble at z = 6.53 . <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/stz3554\">https://doi.org/10.1093/mnras/stz3554</a>","chicago":"Matthee, Jorryt J, David Sobral, Max Gronke, Gabriele Pezzulli, Sebastiano Cantalupo, Huub Röttgering, Behnam Darvish, and Sérgio Santos. “Resolved Lyman-α Properties of a Luminous Lyman-Break Galaxy in a Large Ionized Bubble at z = 6.53 .” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2020. <a href=\"https://doi.org/10.1093/mnras/stz3554\">https://doi.org/10.1093/mnras/stz3554</a>."},"publication_status":"published","keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: evolution","galaxies: high-redshift","dark ages","reionization","first stars","cosmology: observations"],"author":[{"id":"7439a258-f3c0-11ec-9501-9df22fe06720","first_name":"Jorryt J","orcid":"0000-0003-2871-127X","full_name":"Matthee, Jorryt J","last_name":"Matthee"},{"first_name":"David","full_name":"Sobral, David","last_name":"Sobral"},{"first_name":"Max","full_name":"Gronke, Max","last_name":"Gronke"},{"first_name":"Gabriele","last_name":"Pezzulli","full_name":"Pezzulli, Gabriele"},{"full_name":"Cantalupo, Sebastiano","last_name":"Cantalupo","first_name":"Sebastiano"},{"full_name":"Röttgering, Huub","last_name":"Röttgering","first_name":"Huub"},{"first_name":"Behnam","full_name":"Darvish, Behnam","last_name":"Darvish"},{"full_name":"Santos, Sérgio","last_name":"Santos","first_name":"Sérgio"}],"abstract":[{"text":"The observed properties of the Lyman-α (Ly α) emission line are a powerful probe of neutral gas in and around galaxies. We present spatially resolved Ly α spectroscopy with VLT/MUSE targeting VR7, a UV-luminous galaxy at z = 6.532 with moderate Ly α equivalent width (EW0 ≈ 38 Å). These data are combined with deep resolved [CII]158μm spectroscopy obtained with ALMA and UV imaging from HST and we also detect UV continuum with MUSE. Ly α emission is clearly detected with S/N ≈ 40 and FWHM of 374 km s−1. Ly α and [C II] are similarly extended beyond the UV, with effective radius reff = 2.1 ± 0.2 kpc for a single exponential model or reff,Lyα,halo=3.45+1.08−0.87 kpc when measured jointly with the UV continuum. The Ly α profile is broader and redshifted with respect to the [C II] line (by 213 km s−1), but there are spatial variations that are qualitatively similar in both lines and coincide with resolved UV components. This suggests that the emission originates from two components with plausibly different H I column densities. We place VR7 in the context of other galaxies at similar and lower redshift. The Ly α halo scale length is similar at different redshifts and velocity shifts with respect to the systemic are typically smaller. Overall, we find little indications of a more neutral vicinity at higher redshift. This means that the local (∼10 kpc) neutral gas conditions that determine the observed Ly α properties in VR7 resemble the conditions in post-reionization galaxies.","lang":"eng"}],"article_processing_charge":"No","volume":492,"oa":1,"date_updated":"2022-08-18T11:29:53Z","arxiv":1,"quality_controlled":"1","oa_version":"Preprint","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","acknowledgement":"We thank the referee for their suggestions and constructive comments that helped to improve the presentation of our results. Based on observations obtained with the Very Large Telescope, program 99.A-0462. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program #14699. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2017.1.01451.S. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan) and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. MG acknowledges support from NASA grant NNX17AK58G. GP and SC gratefully acknowledge support from Swiss National Science Foundation grant PP00P2 163824. BD acknowledges financial support from the National Science Foundation, grant number 1716907. We have benefited greatly from the public available programming language PYTHON, including the NUMPY, MATPLOTLIB, SCIPY (Jones et al. 2001; Hunter 2007; van der Walt, Colbert & Varoquaux 2011) and ASTROPY (Astropy Collaboration 2013) packages, the astronomical imaging tools SEXTRACTOR, SWARP, and SCAMP (Bertin & Arnouts 1996; Bertin 2006, 2010) and the TOPCAT analysis tool (Taylor 2013).","publication_identifier":{"issn":["0035-8711"],"eissn":["1365-2966"]},"extern":"1","_id":"11534","article_type":"original","date_published":"2020-02-01T00:00:00Z","month":"02","language":[{"iso":"eng"}],"scopus_import":"1","publisher":"Oxford University Press","date_created":"2022-07-07T12:21:36Z","type":"journal_article","day":"01","status":"public","intvolume":"       492","page":"1778-1790","publication":"Monthly Notices of the Royal Astronomical Society","issue":"2"},{"day":"25","type":"journal_article","intvolume":"       628","status":"public","publication":"Astronomy & Astrophysics","month":"07","date_published":"2019-07-25T00:00:00Z","article_type":"original","publisher":"EDP Sciences","scopus_import":"1","language":[{"iso":"eng"}],"date_created":"2022-07-06T10:09:36Z","publication_status":"published","citation":{"chicago":"La Vieuville, G. de, D. Bina, R. Pello, G. Mahler, J. Richard, A. B. Drake, E. C. Herenz, et al. “Faint End of the z ∼ 3–7 Luminosity Function of Lyman-Alpha Emitters behind Lensing Clusters Observed with MUSE.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2019. <a href=\"https://doi.org/10.1051/0004-6361/201834471\">https://doi.org/10.1051/0004-6361/201834471</a>.","apa":"de La Vieuville, G., Bina, D., Pello, R., Mahler, G., Richard, J., Drake, A. B., … Soucail, G. (2019). Faint end of the z ∼ 3–7 luminosity function of Lyman-alpha emitters behind lensing clusters observed with MUSE. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/201834471\">https://doi.org/10.1051/0004-6361/201834471</a>","ieee":"G. de La Vieuville <i>et al.</i>, “Faint end of the z ∼ 3–7 luminosity function of Lyman-alpha emitters behind lensing clusters observed with MUSE,” <i>Astronomy &#38; Astrophysics</i>, vol. 628. EDP Sciences, 2019.","short":"G. de La Vieuville, D. Bina, R. Pello, G. Mahler, J. Richard, A.B. Drake, E.C. Herenz, F.E. Bauer, B. Clément, D. Lagattuta, N. Laporte, J. Martinez, V. Patrício, L. Wisotzki, J. Zabl, R.J. Bouwens, T. Contini, T. Garel, B. Guiderdoni, R.A. Marino, M.V. Maseda, J.J. Matthee, J. Schaye, G. Soucail, Astronomy &#38; Astrophysics 628 (2019).","ista":"de La Vieuville G, Bina D, Pello R, Mahler G, Richard J, Drake AB, Herenz EC, Bauer FE, Clément B, Lagattuta D, Laporte N, Martinez J, Patrício V, Wisotzki L, Zabl J, Bouwens RJ, Contini T, Garel T, Guiderdoni B, Marino RA, Maseda MV, Matthee JJ, Schaye J, Soucail G. 2019. Faint end of the z ∼ 3–7 luminosity function of Lyman-alpha emitters behind lensing clusters observed with MUSE. Astronomy &#38; Astrophysics. 628, A3.","ama":"de La Vieuville G, Bina D, Pello R, et al. Faint end of the z ∼ 3–7 luminosity function of Lyman-alpha emitters behind lensing clusters observed with MUSE. <i>Astronomy &#38; Astrophysics</i>. 2019;628. doi:<a href=\"https://doi.org/10.1051/0004-6361/201834471\">10.1051/0004-6361/201834471</a>","mla":"de La Vieuville, G., et al. “Faint End of the z ∼ 3–7 Luminosity Function of Lyman-Alpha Emitters behind Lensing Clusters Observed with MUSE.” <i>Astronomy &#38; Astrophysics</i>, vol. 628, A3, EDP Sciences, 2019, doi:<a href=\"https://doi.org/10.1051/0004-6361/201834471\">10.1051/0004-6361/201834471</a>."},"abstract":[{"lang":"eng","text":"Contact. This paper presents the results obtained with the Multi-Unit Spectroscopic Explorer (MUSE) at the ESO Very Large Telescope on the faint end of the Lyman-alpha luminosity function (LF) based on deep observations of four lensing clusters. The goal of our project is to set strong constraints on the relative contribution of the Lyman-alpha emitter (LAE) population to cosmic reionization.\r\n\r\nAims. The precise aim of the present study is to further constrain the abundance of LAEs by taking advantage of the magnification provided by lensing clusters to build a blindly selected sample of galaxies which is less biased than current blank field samples in redshift and luminosity. By construction, this sample of LAEs is complementary to those built from deep blank fields, whether observed by MUSE or by other facilities, and makes it possible to determine the shape of the LF at fainter levels, as well as its evolution with redshift.\r\n\r\nMethods. We selected a sample of 156 LAEs with redshifts between 2.9 ≤ z ≤ 6.7 and magnification-corrected luminosities in the range 39 ≲ log LLyα [erg s−1] ≲43. To properly take into account the individual differences in detection conditions between the LAEs when computing the LF, including lensing configurations, and spatial and spectral morphologies, the non-parametric 1/Vmax method was adopted. The price to pay to benefit from magnification is a reduction of the effective volume of the survey, together with a more complex analysis procedure to properly determine the effective volume Vmax for each galaxy. In this paper we present a complete procedure for the determination of the LF based on IFU detections in lensing clusters. This procedure, including some new methods for masking, effective volume integration and (individual) completeness determinations, has been fully automated when possible, and it can be easily generalized to the analysis of IFU observations in blank fields.\r\n\r\nResults. As a result of this analysis, the Lyman-alpha LF has been obtained in four different redshift bins: 2.9 <  z <  6, 7, 2.9 <  z <  4.0, 4.0 <  z <  5.0, and 5.0 <  z <  6.7 with constraints down to log LLyα = 40.5. From our data only, no significant evolution of LF mean slope can be found. When performing a Schechter analysis also including data from the literature to complete the present sample towards the brightest luminosities, a steep faint end slope was measured varying from α = −1.69−0.08+0.08 to α = −1.87−0.12+0.12 between the lowest and the highest redshift bins.\r\n\r\nConclusions. The contribution of the LAE population to the star formation rate density at z ∼ 6 is ≲50% depending on the luminosity limit considered, which is of the same order as the Lyman-break galaxy (LBG) contribution. The evolution of the LAE contribution with redshift depends on the assumed escape fraction of Lyman-alpha photons, and appears to slightly increase with increasing redshift when this fraction is conservatively set to one. Depending on the intersection between the LAE/LBG populations, the contribution of the observed galaxies to the ionizing flux may suffice to keep the universe ionized at z ∼ 6."}],"author":[{"first_name":"G.","full_name":"de La Vieuville, G.","last_name":"de La Vieuville"},{"first_name":"D.","full_name":"Bina, D.","last_name":"Bina"},{"last_name":"Pello","full_name":"Pello, R.","first_name":"R."},{"first_name":"G.","last_name":"Mahler","full_name":"Mahler, G."},{"first_name":"J.","last_name":"Richard","full_name":"Richard, J."},{"first_name":"A. B.","last_name":"Drake","full_name":"Drake, A. B."},{"full_name":"Herenz, E. C.","last_name":"Herenz","first_name":"E. C."},{"last_name":"Bauer","full_name":"Bauer, F. E.","first_name":"F. E."},{"first_name":"B.","full_name":"Clément, B.","last_name":"Clément"},{"last_name":"Lagattuta","full_name":"Lagattuta, D.","first_name":"D."},{"full_name":"Laporte, N.","last_name":"Laporte","first_name":"N."},{"first_name":"J.","full_name":"Martinez, J.","last_name":"Martinez"},{"first_name":"V.","full_name":"Patrício, V.","last_name":"Patrício"},{"first_name":"L.","last_name":"Wisotzki","full_name":"Wisotzki, L."},{"first_name":"J.","full_name":"Zabl, J.","last_name":"Zabl"},{"full_name":"Bouwens, R. J.","last_name":"Bouwens","first_name":"R. J."},{"first_name":"T.","full_name":"Contini, T.","last_name":"Contini"},{"full_name":"Garel, T.","last_name":"Garel","first_name":"T."},{"first_name":"B.","full_name":"Guiderdoni, B.","last_name":"Guiderdoni"},{"last_name":"Marino","full_name":"Marino, R. A.","first_name":"R. A."},{"first_name":"M. V.","last_name":"Maseda","full_name":"Maseda, M. V."},{"id":"7439a258-f3c0-11ec-9501-9df22fe06720","first_name":"Jorryt J","full_name":"Matthee, Jorryt J","last_name":"Matthee","orcid":"0000-0003-2871-127X"},{"full_name":"Schaye, J.","last_name":"Schaye","first_name":"J."},{"full_name":"Soucail, G.","last_name":"Soucail","first_name":"G."}],"keyword":["Space and Planetary Science","Astronomy and Astrophysics","gravitational lensing: strong / galaxies: high-redshift / dark ages","reionization","first stars / galaxies: clusters: general / galaxies: luminosity function","mass function"],"arxiv":1,"volume":628,"date_updated":"2022-07-19T09:36:31Z","oa":1,"article_processing_charge":"No","_id":"11505","publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"extern":"1","acknowledgement":"We thank the anonymous referee for their critical review and useful suggestions. This work has been carried out thanks to the support of the OCEVU Labex (ANR-11-LABX-0060) and the A*MIDEX project (ANR-11-IDEX-0001-02) funded by the “Investissements d’Avenir” French government programme managed by the ANR. Partially funded by the ERC starting grant CALENDS (JR, VP, BC, JM), the Agence Nationale de la recherche bearing the reference ANR-13-BS05-0010-02 (FOGHAR), and the “Programme National de Cosmologie and Galaxies” (PNCG) of CNRS/INSU, France. GdV, RP, JR, GM, JM, BC, and VP also acknowledge support by the Programa de Cooperacion Cientifica – ECOS SUD Program C16U02. NL acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 669253), ABD acknowledges support from the ERC advanced grant “Cosmic Gas”. LW acknowledges support by the Competitive Fund of the Leibniz Association through grant SAW-2015-AIP-2, and TG acknowledges support from the European Research Council under grant agreement ERC-stg-757258 (TRIPLE).. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme IDs 060.A-9345, 094.A-0115, 095.A-0181, 096.A-0710, 097.A0269, 100.A-0249, and 294.A-5032. Also based on observations obtained with the NASA/ESA Hubble Space Telescope, retrieved from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute (STScI). STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555. This research made use of Astropy, a community-developed core Python package for Astronomy (Astropy Collaboration 2013). All plots in this paper were created using Matplotlib (Hunter 2007).","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa_version":"Published Version","quality_controlled":"1","doi":"10.1051/0004-6361/201834471","year":"2019","title":"Faint end of the z ∼ 3–7 luminosity function of Lyman-alpha emitters behind lensing clusters observed with MUSE","external_id":{"arxiv":["1905.13696"]},"article_number":"A3","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1905.13696"}]},{"main_file_link":[{"url":"https://arxiv.org/abs/1710.08422","open_access":"1"}],"title":"On the nature and physical conditions of the luminous Ly α emitter CR7 and its rest-frame UV components","external_id":{"arxiv":["1710.08422"]},"doi":"10.1093/mnras/sty2779","year":"2019","oa_version":"Preprint","quality_controlled":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","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.","extern":"1","publication_identifier":{"issn":["0035-8711"],"eissn":["1365-2966"]},"_id":"11541","article_processing_charge":"No","volume":482,"oa":1,"date_updated":"2022-08-19T06:49:36Z","arxiv":1,"author":[{"last_name":"Sobral","full_name":"Sobral, David","first_name":"David"},{"id":"7439a258-f3c0-11ec-9501-9df22fe06720","first_name":"Jorryt J","orcid":"0000-0003-2871-127X","full_name":"Matthee, Jorryt J","last_name":"Matthee"},{"first_name":"Gabriel","full_name":"Brammer, Gabriel","last_name":"Brammer"},{"first_name":"Andrea","last_name":"Ferrara","full_name":"Ferrara, Andrea"},{"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"},{"full_name":"Mobasher, Bahram","last_name":"Mobasher","first_name":"Bahram"},{"full_name":"Darvish, Behnam","last_name":"Darvish","first_name":"Behnam"}],"keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: evolution","galaxies: high-redshift","galaxies: ISM","cosmology: observations","dark ages","reionization","first stars","early Universe"],"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."}],"citation":{"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>.","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>","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.","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.","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.","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>","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>."},"publication_status":"published","date_created":"2022-07-08T10:40:05Z","language":[{"iso":"eng"}],"scopus_import":"1","publisher":"Oxford University Press","article_type":"original","date_published":"2019-01-01T00:00:00Z","month":"01","page":"2422-2441","publication":"Monthly Notices of the Royal Astronomical Society","issue":"2","status":"public","intvolume":"       482","type":"journal_article","day":"01"},{"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1805.11621"}],"article_number":"A136","title":"Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe","external_id":{"arxiv":["1805.11621"]},"doi":"10.1051/0004-6361/201833528","year":"2018","acknowledgement":"JM acknowledges the award of a Huygens PhD fellowship from Leiden University. MG acknowledges support from NASA grant NNX17AK58G. APA, PhD::SPACE fellow, acknowledges support from the FCT through the fellowship PD/BD/52706/2014. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme IDs 294.A-5018, 098.A-0819, 099.A-0254 and 0100.A-0213. We are grateful for the excellent data-sets from the COSMOS and UltraVISTA survey teams. This research was supported by the Munich Institute for Astro- and Particle Physics (MIAPP) of the DFG cluster of excellence “Origin and Structure of the Universe”. We thank the referee for their comments that improved the paper. We also thank Christoph Behrens, Len Cowie, Koki Kakiichi, Peter Laursen, Charlotte Mason, Eros Vanzella, Lewis Weinberger and Johannes Zabl for discussions. We have benefited from the public available programming language Python, including the numpy, matplotlib, scipy and astropy packages (Hunter 2007; Astropy Collaboration 2013), the astronomical imaging tools Swarp (Bertin 2010) and ds9 and the Topcat analysis tool (Taylor 2013).","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa_version":"Published Version","quality_controlled":"1","_id":"11508","extern":"1","publication_identifier":{"issn":["0004-6361"],"eissn":["1432-0746"]},"oa":1,"volume":619,"date_updated":"2022-07-19T09:32:08Z","article_processing_charge":"No","arxiv":1,"author":[{"first_name":"Jorryt J","full_name":"Matthee, Jorryt J","last_name":"Matthee","orcid":"0000-0003-2871-127X","id":"7439a258-f3c0-11ec-9501-9df22fe06720"},{"last_name":"Sobral","full_name":"Sobral, David","first_name":"David"},{"first_name":"Max","full_name":"Gronke, Max","last_name":"Gronke"},{"full_name":"Paulino-Afonso, Ana","last_name":"Paulino-Afonso","first_name":"Ana"},{"last_name":"Stefanon","full_name":"Stefanon, Mauro","first_name":"Mauro"},{"first_name":"Huub","full_name":"Röttgering, Huub","last_name":"Röttgering"}],"keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: high-redshift / galaxies: formation / dark ages / reionization / first stars / techniques: spectroscopic / intergalactic medium"],"abstract":[{"lang":"eng","text":"Distant luminous Lyman-α emitters (LAEs) are excellent targets for spectroscopic observations of galaxies in the epoch of reionisation (EoR). We present deep high-resolution (R = 5000) VLT/X-shooter observations, along with an extensive collection of photometric data of COLA1, a proposed double peaked LAE at z = 6.6. We rule out the possibility that COLA1’s emission line is an [OII] doublet at z = 1.475 on the basis of i) the asymmetric red line-profile and flux ratio of the peaks (blue/red=0.31 ± 0.03) and ii) an unphysical [OII]/Hα ratio ([OII]/Hα >  22). We show that COLA1’s observed B-band flux is explained by a faint extended foreground LAE, for which we detect Lyα and [OIII] at z = 2.142. We thus conclude that COLA1 is a real double-peaked LAE at z = 6.593, the first discovered at z >  6. COLA1 is UV luminous (M1500 = −21.6 ± 0.3), has a high equivalent width (EW0,Lyα = 120−40+50 Å) and very compact Lyα emission (r50,Lyα = 0.33−0.04+0.07 kpc). Relatively weak inferred Hβ+[OIII] line-emission from Spitzer/IRAC indicates an extremely low metallicity of Z <  1/20 Z⊙ or reduced strength of nebular lines due to high escape of ionising photons. The small Lyα peak separation of 220 ± 20 km s−1 implies a low HI column density and an ionising photon escape fraction of ≈15 − 30%, providing the first direct evidence that such galaxies contribute actively to the reionisation of the Universe at z >  6. Based on simple estimates, we find that COLA1 could have provided just enough photons to reionise its own ≈0.3 pMpc (2.3 cMpc) bubble, allowing the blue Lyα line to be observed. However, we also discuss alternative scenarios explaining the detected double peaked nature of COLA1. Our results show that future high-resolution observations of statistical samples of double peaked LAEs at z >  5 are a promising probe of the occurrence of ionised regions around galaxies in the EoR."}],"publication_status":"published","citation":{"ista":"Matthee JJ, Sobral D, Gronke M, Paulino-Afonso A, Stefanon M, Röttgering H. 2018. Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe. Astronomy &#38; Astrophysics. 619, A136.","short":"J.J. Matthee, D. Sobral, M. Gronke, A. Paulino-Afonso, M. Stefanon, H. Röttgering, Astronomy &#38; Astrophysics 619 (2018).","mla":"Matthee, Jorryt J., et al. “Confirmation of Double Peaked Lyα Emission at z = 6.593: Witnessing a Galaxy Directly Contributing to the Reionisation of the Universe.” <i>Astronomy &#38; Astrophysics</i>, vol. 619, A136, EDP Sciences, 2018, doi:<a href=\"https://doi.org/10.1051/0004-6361/201833528\">10.1051/0004-6361/201833528</a>.","ama":"Matthee JJ, Sobral D, Gronke M, Paulino-Afonso A, Stefanon M, Röttgering H. Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe. <i>Astronomy &#38; Astrophysics</i>. 2018;619. doi:<a href=\"https://doi.org/10.1051/0004-6361/201833528\">10.1051/0004-6361/201833528</a>","chicago":"Matthee, Jorryt J, David Sobral, Max Gronke, Ana Paulino-Afonso, Mauro Stefanon, and Huub Röttgering. “Confirmation of Double Peaked Lyα Emission at z = 6.593: Witnessing a Galaxy Directly Contributing to the Reionisation of the Universe.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2018. <a href=\"https://doi.org/10.1051/0004-6361/201833528\">https://doi.org/10.1051/0004-6361/201833528</a>.","apa":"Matthee, J. J., Sobral, D., Gronke, M., Paulino-Afonso, A., Stefanon, M., &#38; Röttgering, H. (2018). Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/201833528\">https://doi.org/10.1051/0004-6361/201833528</a>","ieee":"J. J. Matthee, D. Sobral, M. Gronke, A. Paulino-Afonso, M. Stefanon, and H. Röttgering, “Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe,” <i>Astronomy &#38; Astrophysics</i>, vol. 619. EDP Sciences, 2018."},"date_created":"2022-07-06T11:14:23Z","language":[{"iso":"eng"}],"publisher":"EDP Sciences","scopus_import":"1","article_type":"original","date_published":"2018-11-19T00:00:00Z","month":"11","publication":"Astronomy & Astrophysics","status":"public","intvolume":"       619","type":"journal_article","day":"19"},{"issue":"2","publication":"The Astrophysical Journal","intvolume":"       851","status":"public","day":"21","type":"journal_article","date_created":"2022-07-07T08:48:04Z","publisher":"IOP Publishing","scopus_import":"1","language":[{"iso":"eng"}],"month":"12","date_published":"2017-12-21T00:00:00Z","article_type":"original","_id":"11518","extern":"1","publication_identifier":{"eissn":["1538-4357"],"issn":["0004-637X"]},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","acknowledgement":"We thank the referee for their constructive comments, which have helped improve the quality and clarity of this work. We thank Raffaella Schneider for comments on an earlier version of this paper. We thank Leindert Boogaard, Steven Bos, Rychard Bouwens, and Renske Smit for discussions. J.M. acknowledges the support of a Huygens PhD fellowship from Leiden University. D.S. acknowledges financial support from the Netherlands Organisation for Scientific research (NWO) through a Veni fellowship and from Lancaster University through an Early Career Internal Grant A100679. A.F. acknowledges support from the ERC Advanced Grant INTERSTELLAR H2020/740120. B.D. acknowledges financial support from NASA through the Astrophysics Data Analysis Program (ADAP), grant number NNX12AE20G. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 294.A-5018. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2015.1.00122.S. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ.","quality_controlled":"1","oa_version":"Preprint","arxiv":1,"oa":1,"volume":851,"date_updated":"2022-08-18T10:23:35Z","article_processing_charge":"No","abstract":[{"lang":"eng","text":"We present spectroscopic follow-up observations of CR7 with ALMA, targeted at constraining the infrared (IR) continuum and [C II]158 mm line-emission at high spatial resolution matched to the HST/WFC3 imaging. CR7 is a luminous Lyα emitting galaxy at z = 6.6 that consists of three separated UV-continuum components. Our observations reveal several well-separated components of [C II] emission. The two most luminous components in [C II] coincide with the brightest UV components (A and B), blueshifted by »150 km s−1 with respect to the\r\npeak of Lyα emission. Other [C II] components are observed close to UV clumps B and C and are blueshifted by »300 and ≈80 km s−1 with respect to the systemic redshift. We do not detect FIR continuum emission due to dust with a 3σ limiting luminosity LIR T L d 35 K 3.1 10 = <´ 10 ( ) . This allows us to mitigate uncertainties in the dust-corrected SFR and derive SFRs for the three UV clumps A, B, and C of 28, 5, and 7 M yr−1. All clumps have [C II] luminosities consistent within the scatter observed in the local relation between SFR and L[ ] C II , implying that strong Lyα emission does not necessarily anti-correlate with [C II] luminosity. Combining\r\nour measurements with the literature, we show that galaxies with blue UV slopes have weaker [C II] emission at fixed SFR, potentially due to their lower metallicities and/or higher photoionization. Comparison with hydrodynamical simulations suggests that CR7ʼs clumps have metallicities of 0.1 Z Z 0.2 < < . The observed ISM structure of CR7 indicates that we are likely witnessing the build up of a central galaxy in the early universe through complex accretion of satellites."}],"keyword":["Space and Planetary Science","Astronomy and Astrophysics","dark ages","reionization","first stars – galaxies: formation – galaxies: high-redshift – galaxies: ISM – galaxies: kinematics and dynamics"],"author":[{"last_name":"Matthee","full_name":"Matthee, Jorryt J","orcid":"0000-0003-2871-127X","first_name":"Jorryt J","id":"7439a258-f3c0-11ec-9501-9df22fe06720"},{"last_name":"Sobral","full_name":"Sobral, D.","first_name":"D."},{"full_name":"Boone, F.","last_name":"Boone","first_name":"F."},{"first_name":"H.","last_name":"Röttgering","full_name":"Röttgering, H."},{"full_name":"Schaerer, D.","last_name":"Schaerer","first_name":"D."},{"full_name":"Girard, M.","last_name":"Girard","first_name":"M."},{"full_name":"Pallottini, A.","last_name":"Pallottini","first_name":"A."},{"last_name":"Vallini","full_name":"Vallini, L.","first_name":"L."},{"last_name":"Ferrara","full_name":"Ferrara, A.","first_name":"A."},{"full_name":"Darvish, B.","last_name":"Darvish","first_name":"B."},{"first_name":"B.","last_name":"Mobasher","full_name":"Mobasher, B."}],"publication_status":"published","citation":{"ama":"Matthee JJ, Sobral D, Boone F, et al. ALMA reveals metals yet no dust within multiple components in CR7. <i>The Astrophysical Journal</i>. 2017;851(2). doi:<a href=\"https://doi.org/10.3847/1538-4357/aa9931\">10.3847/1538-4357/aa9931</a>","mla":"Matthee, Jorryt J., et al. “ALMA Reveals Metals yet No Dust within Multiple Components in CR7.” <i>The Astrophysical Journal</i>, vol. 851, no. 2, 145, IOP Publishing, 2017, doi:<a href=\"https://doi.org/10.3847/1538-4357/aa9931\">10.3847/1538-4357/aa9931</a>.","short":"J.J. Matthee, D. Sobral, F. Boone, H. Röttgering, D. Schaerer, M. Girard, A. Pallottini, L. Vallini, A. Ferrara, B. Darvish, B. Mobasher, The Astrophysical Journal 851 (2017).","ista":"Matthee JJ, Sobral D, Boone F, Röttgering H, Schaerer D, Girard M, Pallottini A, Vallini L, Ferrara A, Darvish B, Mobasher B. 2017. ALMA reveals metals yet no dust within multiple components in CR7. The Astrophysical Journal. 851(2), 145.","ieee":"J. J. Matthee <i>et al.</i>, “ALMA reveals metals yet no dust within multiple components in CR7,” <i>The Astrophysical Journal</i>, vol. 851, no. 2. IOP Publishing, 2017.","apa":"Matthee, J. J., Sobral, D., Boone, F., Röttgering, H., Schaerer, D., Girard, M., … Mobasher, B. (2017). ALMA reveals metals yet no dust within multiple components in CR7. <i>The Astrophysical Journal</i>. IOP Publishing. <a href=\"https://doi.org/10.3847/1538-4357/aa9931\">https://doi.org/10.3847/1538-4357/aa9931</a>","chicago":"Matthee, Jorryt J, D. Sobral, F. Boone, H. Röttgering, D. Schaerer, M. Girard, A. Pallottini, et al. “ALMA Reveals Metals yet No Dust within Multiple Components in CR7.” <i>The Astrophysical Journal</i>. IOP Publishing, 2017. <a href=\"https://doi.org/10.3847/1538-4357/aa9931\">https://doi.org/10.3847/1538-4357/aa9931</a>."},"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1709.06569"}],"article_number":"145","external_id":{"arxiv":["1709.06569"]},"title":"ALMA reveals metals yet no dust within multiple components in CR7","doi":"10.3847/1538-4357/aa9931","year":"2017"},{"date_published":"2017-03-01T00:00:00Z","article_type":"original","month":"03","language":[{"iso":"eng"}],"publisher":"Oxford University Press","scopus_import":"1","date_created":"2022-07-12T12:12:14Z","type":"journal_article","day":"01","status":"public","intvolume":"       465","page":"3637-3655","issue":"3","publication":"Monthly Notices of the Royal Astronomical Society","year":"2017","doi":"10.1093/mnras/stw2973","title":"The production and escape of Lyman-Continuum radiation from star-forming galaxies at z ∼ 2 and their redshift evolution","external_id":{"arxiv":["1605.08782"]},"main_file_link":[{"url":"https://arxiv.org/abs/1605.08782","open_access":"1"}],"publication_status":"published","citation":{"ieee":"J. J. Matthee <i>et al.</i>, “The production and escape of Lyman-Continuum radiation from star-forming galaxies at z ∼ 2 and their redshift evolution,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 465, no. 3. Oxford University Press, pp. 3637–3655, 2017.","apa":"Matthee, J. J., Sobral, D., Best, P., Khostovan, A. A., Oteo, I., Bouwens, R., &#38; Röttgering, H. (2017). The production and escape of Lyman-Continuum radiation from star-forming galaxies at z ∼ 2 and their redshift evolution. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/stw2973\">https://doi.org/10.1093/mnras/stw2973</a>","chicago":"Matthee, Jorryt J, David Sobral, Philip Best, Ali Ahmad Khostovan, Iván Oteo, Rychard Bouwens, and Huub Röttgering. “The Production and Escape of Lyman-Continuum Radiation from Star-Forming Galaxies at z ∼ 2 and Their Redshift Evolution.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2017. <a href=\"https://doi.org/10.1093/mnras/stw2973\">https://doi.org/10.1093/mnras/stw2973</a>.","ama":"Matthee JJ, Sobral D, Best P, et al. The production and escape of Lyman-Continuum radiation from star-forming galaxies at z ∼ 2 and their redshift evolution. <i>Monthly Notices of the Royal Astronomical Society</i>. 2017;465(3):3637-3655. doi:<a href=\"https://doi.org/10.1093/mnras/stw2973\">10.1093/mnras/stw2973</a>","mla":"Matthee, Jorryt J., et al. “The Production and Escape of Lyman-Continuum Radiation from Star-Forming Galaxies at z ∼ 2 and Their Redshift Evolution.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 465, no. 3, Oxford University Press, 2017, pp. 3637–55, doi:<a href=\"https://doi.org/10.1093/mnras/stw2973\">10.1093/mnras/stw2973</a>.","ista":"Matthee JJ, Sobral D, Best P, Khostovan AA, Oteo I, Bouwens R, Röttgering H. 2017. The production and escape of Lyman-Continuum radiation from star-forming galaxies at z ∼ 2 and their redshift evolution. Monthly Notices of the Royal Astronomical Society. 465(3), 3637–3655.","short":"J.J. Matthee, D. Sobral, P. Best, A.A. Khostovan, I. Oteo, R. Bouwens, H. Röttgering, Monthly Notices of the Royal Astronomical Society 465 (2017) 3637–3655."},"keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: evolution","galaxies: high-redshift","cosmology: observations","dark ages","reionization","first stars"],"author":[{"first_name":"Jorryt J","orcid":"0000-0003-2871-127X","full_name":"Matthee, Jorryt J","last_name":"Matthee","id":"7439a258-f3c0-11ec-9501-9df22fe06720"},{"full_name":"Sobral, David","last_name":"Sobral","first_name":"David"},{"first_name":"Philip","full_name":"Best, Philip","last_name":"Best"},{"last_name":"Khostovan","full_name":"Khostovan, Ali Ahmad","first_name":"Ali Ahmad"},{"last_name":"Oteo","full_name":"Oteo, Iván","first_name":"Iván"},{"full_name":"Bouwens, Rychard","last_name":"Bouwens","first_name":"Rychard"},{"full_name":"Röttgering, Huub","last_name":"Röttgering","first_name":"Huub"}],"abstract":[{"lang":"eng","text":"We study the production rate of ionizing photons of a sample of 588 Hα emitters (HAEs) and 160 Lyman-α emitters (LAEs) at z = 2.2 in the COSMOS field in order to assess the implied emissivity from galaxies, based on their ultraviolet (UV) luminosity. By exploring the rest-frame Lyman Continuum (LyC) with GALEX/NUV data, we find fesc < 2.8 (6.4) per cent through median (mean) stacking. By combining the Hα luminosity density with intergalactic medium emissivity measurements from absorption studies, we find a globally averaged 〈fesc〉 of 5.9+14.5−4.2 per cent at z = 2.2 if we assume HAEs are the only source of ionizing photons. We find similarly low values of the global 〈fesc〉 at z ≈ 3–5, also ruling out a high 〈fesc〉 at z < 5. These low escape fractions allow us to measure ξion, the number of produced ionizing photons per unit UV luminosity, and investigate how this depends on galaxy properties. We find a typical ξion ≈ 1024.77 ± 0.04 Hz erg−1 for HAEs and ξion ≈ 1025.14 ± 0.09 Hz erg−1 for LAEs. LAEs and low-mass HAEs at z = 2.2 show similar values of ξion as typically assumed in the reionization era, while the typical HAE is three times less ionizing. Due to an increasing ξion with increasing EW(Hα), ξion likely increases with redshift. This evolution alone is fully in line with the observed evolution of ξion between z ≈ 2 and 5, indicating a typical value of ξion ≈ 1025.4 Hz erg−1 in the reionization era."}],"oa":1,"volume":465,"date_updated":"2022-08-19T07:53:04Z","article_processing_charge":"No","arxiv":1,"acknowledgement":"We thank the referee for the many helpful and constructive comments which have significantly improved this paper. JM acknowledges the support of a Huygens PhD fellowship from Leiden University. DS acknowledges financial support from the Netherlands Organization for Scientific research (NWO) through a Veni fellowship and from FCT through an FCT Investigator Starting Grant and Start-up Grant (IF/01154/2012/CP0189/CT0010). PNB is grateful for support from the UK STFC via grant ST/M001229/1. IO acknowledges support from the European Research Council in the form of the Advanced Investigator Programme, 321302, COSMICISM. The authors thank Andreas Faisst, Michael Rutkowski and Andreas Sandberg for answering questions related to this work and Daniel Schaerer and Mark Dijkstra for discussions. We acknowledge the work that has been done by both the COSMOS team in assembling such large, state-of-the-art multi-wavelength data set, as this has been crucial for the results presented in this paper. We have benefited greatly from the public available programming language PYTHON, including the NUMPY, MATPLOTLIB, PYFITS, SCIPY (Jones et al. 2001; Hunter 2007; Van Der Walt, Colbert & Varoquaux 2011) and ASTROPY (Astropy Collaboration et al. 2013) packages, the astronomical imaging tools SEXTRACTOR and SWARP (Bertin & Arnouts 1996;\r\nBertin 2010) and the TOPCAT analysis program (Taylor 2013).","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","quality_controlled":"1","oa_version":"Preprint","_id":"11564","extern":"1","publication_identifier":{"eissn":["1365-2966"],"issn":["0035-8711"]}},{"author":[{"id":"7439a258-f3c0-11ec-9501-9df22fe06720","first_name":"Jorryt J","orcid":"0000-0003-2871-127X","full_name":"Matthee, Jorryt J","last_name":"Matthee"},{"first_name":"David","full_name":"Sobral, David","last_name":"Sobral"},{"last_name":"Darvish","full_name":"Darvish, Behnam","first_name":"Behnam"},{"first_name":"Sérgio","last_name":"Santos","full_name":"Santos, Sérgio"},{"first_name":"Bahram","last_name":"Mobasher","full_name":"Mobasher, Bahram"},{"first_name":"Ana","full_name":"Paulino-Afonso, Ana","last_name":"Paulino-Afonso"},{"first_name":"Huub","full_name":"Röttgering, Huub","last_name":"Röttgering"},{"full_name":"Alegre, Lara","last_name":"Alegre","first_name":"Lara"}],"keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: evolution – galaxies: high-redshift","dark ages","reionization","first stars","cosmology: observations"],"abstract":[{"lang":"eng","text":"We present spectroscopic follow-up of candidate luminous Ly α emitters (LAEs) at z = 5.7–6.6 in the SA22 field with VLT/X-SHOOTER. We confirm two new luminous LAEs at z = 5.676 (SR6) and z = 6.532 (VR7), and also present HST follow-up of both sources. These sources have luminosities LLy α ≈ 3 × 1043 erg s−1, very high rest-frame equivalent widths of EW0 ≳ 200 Å and narrow Ly α lines (200–340 km s−1). VR7 is the most UV-luminous LAE at z > 6.5, with M1500 = −22.5, even brighter in the UV than CR7. Besides Ly α, we do not detect any other rest-frame UV lines in the spectra of SR6 and VR7, and argue that rest-frame UV lines are easier to observe in bright galaxies with low Ly α equivalent widths. We confirm that Ly α line widths increase with Ly α luminosity at z = 5.7, while there are indications that Ly α lines of faint LAEs become broader at z = 6.6, potentially due to reionization. We find a large spread of up to 3 dex in UV luminosity for >L⋆ LAEs, but find that the Ly α luminosity of the brightest LAEs is strongly related to UV luminosity at z = 6.6. Under basic assumptions, we find that several LAEs at z ≈ 6–7 have Ly α escape fractions ≳ 100  per cent, indicating bursty star formation histories, alternative Ly α production mechanisms, or dust attenuating Ly α emission differently than UV emission. Finally, we present a method to compute ξion, the production efficiency of ionizing photons, and find that LAEs at z ≈ 6–7 have high values of log10(ξion/Hz erg−1) ≈ 25.51 ± 0.09 that may alleviate the need for high Lyman-Continuum escape fractions required for reionization."}],"publication_status":"published","citation":{"apa":"Matthee, J. J., Sobral, D., Darvish, B., Santos, S., Mobasher, B., Paulino-Afonso, A., … Alegre, L. (2017). Spectroscopic properties of luminous Ly α emitters at z ≈ 6–7 and comparison to the Lyman-break population. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/stx2061\">https://doi.org/10.1093/mnras/stx2061</a>","ieee":"J. J. Matthee <i>et al.</i>, “Spectroscopic properties of luminous Ly α emitters at z ≈ 6–7 and comparison to the Lyman-break population,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 472, no. 1. Oxford University Press, pp. 772–787, 2017.","chicago":"Matthee, Jorryt J, David Sobral, Behnam Darvish, Sérgio Santos, Bahram Mobasher, Ana Paulino-Afonso, Huub Röttgering, and Lara Alegre. “Spectroscopic Properties of Luminous Ly α Emitters at z ≈ 6–7 and Comparison to the Lyman-Break Population.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2017. <a href=\"https://doi.org/10.1093/mnras/stx2061\">https://doi.org/10.1093/mnras/stx2061</a>.","mla":"Matthee, Jorryt J., et al. “Spectroscopic Properties of Luminous Ly α Emitters at z ≈ 6–7 and Comparison to the Lyman-Break Population.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 472, no. 1, Oxford University Press, 2017, pp. 772–87, doi:<a href=\"https://doi.org/10.1093/mnras/stx2061\">10.1093/mnras/stx2061</a>.","ama":"Matthee JJ, Sobral D, Darvish B, et al. Spectroscopic properties of luminous Ly α emitters at z ≈ 6–7 and comparison to the Lyman-break population. <i>Monthly Notices of the Royal Astronomical Society</i>. 2017;472(1):772-787. doi:<a href=\"https://doi.org/10.1093/mnras/stx2061\">10.1093/mnras/stx2061</a>","short":"J.J. Matthee, D. Sobral, B. Darvish, S. Santos, B. Mobasher, A. Paulino-Afonso, H. Röttgering, L. Alegre, Monthly Notices of the Royal Astronomical Society 472 (2017) 772–787.","ista":"Matthee JJ, Sobral D, Darvish B, Santos S, Mobasher B, Paulino-Afonso A, Röttgering H, Alegre L. 2017. Spectroscopic properties of luminous Ly α emitters at z ≈ 6–7 and comparison to the Lyman-break population. Monthly Notices of the Royal Astronomical Society. 472(1), 772–787."},"acknowledgement":"We thank the referee for a constructive report that has improved the quality and clarity of this work. The authors thank Grecco Oyarzún for discussions. JM acknowledges the support of a Huygens PhD fellowship from Leiden University. DS acknowledges financial support from the Netherlands Organisation for Scientific research (NWO) through a Veni fellowship and from Lancaster University through an Early Career Internal Grant A100679. BD acknowledges financial support from NASA through the Astrophysics Data Analysis Program (ADAP), grant number NNX12AE20G. We thank Kasper Schmidt for providing measurements. Based on observations with the W.M. Keck Observatory through programme C267D. The W.M. Keck Observatory is operated as a scientific partnership amongst the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme IDs 097.A-0943, 294.A 5018 and 098.A-0819 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 observing time (W16AN004) and 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. Based on observations made with the NASA/ESA HST, obtained (from the Data Archive) at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programme #14699. We are grateful for the excellent data sets from the COSMOS, UltraVISTA, SXDS, UDS and CFHTLS survey teams; without these legacy surveys, this research would have been impossible. We have benefited from the public available programming language PYTHON, including the NUMPY, MATPLOTLIB, PYFITS, SCIPY and ASTROPY packages, the astronomical imaging tools SEXTRACTOR, SWARP and SCAMP and the TOPCAT analysis tool (Taylor 2013).","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","quality_controlled":"1","oa_version":"Preprint","_id":"11572","publication_identifier":{"eissn":["1365-2966"],"issn":["0035-8711"]},"extern":"1","volume":472,"date_updated":"2022-08-19T08:05:37Z","oa":1,"article_processing_charge":"No","arxiv":1,"title":"Spectroscopic properties of luminous Ly α emitters at z ≈ 6–7 and comparison to the Lyman-break population","external_id":{"arxiv":["1706.06591"]},"doi":"10.1093/mnras/stx2061","year":"2017","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1706.06591"}],"status":"public","intvolume":"       472","type":"journal_article","day":"01","page":"772-787","issue":"1","publication":"Monthly Notices of the Royal Astronomical Society","language":[{"iso":"eng"}],"publisher":"Oxford University Press","scopus_import":"1","date_published":"2017-11-01T00:00:00Z","article_type":"original","month":"11","date_created":"2022-07-13T09:47:39Z"},{"publication":"Monthly Notices of the Royal Astronomical Society","issue":"2","page":"1678-1691","day":"01","type":"journal_article","intvolume":"       463","status":"public","date_created":"2022-07-13T10:08:20Z","month":"12","article_type":"original","date_published":"2016-12-01T00:00:00Z","scopus_import":"1","publisher":"Oxford University Press","language":[{"iso":"eng"}],"arxiv":1,"article_processing_charge":"No","oa":1,"volume":463,"date_updated":"2022-08-19T08:09:54Z","publication_identifier":{"eissn":["1365-2966"],"issn":["0035-8711"]},"extern":"1","_id":"11574","quality_controlled":"1","oa_version":"Preprint","acknowledgement":"We thank the anonymous referee for useful and constructive comments and suggestions which greatly improved the quality and clarity of our work. The authors acknowledge financial support from the Netherlands Organisation for Scientific research (NWO) through a Veni fellowship. SS and DS acknowledge funding from FCT through an FCT Investigator Starting Grant and Start-up Grant (IF/01154/2012/CP0189/CT0010). SS also acknowledges support from FCT through the research grants UID/FIS/04434/2013 and PTDC/FIS-AST/2194/2012. JM acknowledges a Huygens PhD fellowship from Leiden University. Based on observations with the Subaru Telescope (Program IDs: S05B-027, S06A-025, S06B-010, S07A-013, S07B-008, S08B-008, S09A-017, S14A-086). Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 294.A-5018. 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 l’Univers 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 ID 179.A-2005 and on data products produced by TERAPIX and the Cambridge Astronomy Survey Unit on behalf of the UltraVISTA consortium. We are grateful to the CFHTLS, COSMOS-UltraVISTA, UKIDSS, SXDF and COSMOS survey teams. Without these legacy surveys, this research would have been impossible. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct and explore observations from this mountain. Finally, the authors acknowledge the unique value of the publicly available programming language PYTHON, including the NUMPY, PYFITS, MATPLOTLIB, SCIPY and ASTROPY (Astropy Collaboration et al.","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","citation":{"short":"S. Santos, D. Sobral, J.J. Matthee, Monthly Notices of the Royal Astronomical Society 463 (2016) 1678–1691.","ista":"Santos S, Sobral D, Matthee JJ. 2016. The Lyα luminosity function at z= 5.7–6.6 and the steep drop of the faint end: Implications for reionization. Monthly Notices of the Royal Astronomical Society. 463(2), 1678–1691.","mla":"Santos, Sérgio, et al. “The Lyα Luminosity Function at Z= 5.7–6.6 and the Steep Drop of the Faint End: Implications for Reionization.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 463, no. 2, Oxford University Press, 2016, pp. 1678–91, doi:<a href=\"https://doi.org/10.1093/mnras/stw2076\">10.1093/mnras/stw2076</a>.","ama":"Santos S, Sobral D, Matthee JJ. The Lyα luminosity function at z= 5.7–6.6 and the steep drop of the faint end: Implications for reionization. <i>Monthly Notices of the Royal Astronomical Society</i>. 2016;463(2):1678-1691. doi:<a href=\"https://doi.org/10.1093/mnras/stw2076\">10.1093/mnras/stw2076</a>","chicago":"Santos, Sérgio, David Sobral, and Jorryt J Matthee. “The Lyα Luminosity Function at Z= 5.7–6.6 and the Steep Drop of the Faint End: Implications for Reionization.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2016. <a href=\"https://doi.org/10.1093/mnras/stw2076\">https://doi.org/10.1093/mnras/stw2076</a>.","ieee":"S. Santos, D. Sobral, and J. J. Matthee, “The Lyα luminosity function at z= 5.7–6.6 and the steep drop of the faint end: Implications for reionization,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 463, no. 2. Oxford University Press, pp. 1678–1691, 2016.","apa":"Santos, S., Sobral, D., &#38; Matthee, J. J. (2016). The Lyα luminosity function at z= 5.7–6.6 and the steep drop of the faint end: Implications for reionization. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/stw2076\">https://doi.org/10.1093/mnras/stw2076</a>"},"publication_status":"published","abstract":[{"lang":"eng","text":"We present new results from the widest narrow-band survey search for Lyα emitters at z = 5.7, just after reionization. We survey a total of 7 deg2 spread over the COSMOS, UDS and SA22 fields. We find over 11 000 line emitters, out of which 514 are robust Lyα candidates at z = 5.7 within a volume of 6.3 × 106 Mpc3. Our Lyα emitters span a wide range in Lyα luminosities, from faint to bright (LLyα ∼ 1042.5–44 erg s−1) and rest-frame equivalent widths (EW0 ∼ 25–1000 Å) in a single, homogeneous data set. By combining all our fields, we find that the faint end slope of the z = 5.7 Lyα luminosity function is very steep, with α=−2.3+0.4−0.3⁠. We also present an updated z = 6.6 Lyα luminosity function, based on comparable volumes and obtained with the same methods, which we directly compare with that at z = 5.7. We find a significant decline of the number density of faint Lyα emitters from z = 5.7 to 6.6 (by 0.5 ± 0.1 dex), but no evolution at the bright end/no evolution in L*. Faint Lyα emitters at z = 6.6 show much more extended haloes than those at z = 5.7, suggesting that neutral Hydrogen plays an important role, increasing the scattering and leading to observations missing faint Lyα emission within the epoch of reionization. Altogether, our results suggest that we are observing patchy reionization which happens first around the brightest Lyα emitters, allowing the number densities of those sources to remain unaffected by the increase of neutral Hydrogen fraction from z ∼ 5 to 7."}],"author":[{"first_name":"Sérgio","full_name":"Santos, Sérgio","last_name":"Santos"},{"full_name":"Sobral, David","last_name":"Sobral","first_name":"David"},{"last_name":"Matthee","full_name":"Matthee, Jorryt J","orcid":"0000-0003-2871-127X","first_name":"Jorryt J","id":"7439a258-f3c0-11ec-9501-9df22fe06720"}],"keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: high-redshift","galaxies: luminosity function","mass function","cosmology: observations","dark ages","reionization","first stars"],"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1606.07435"}],"doi":"10.1093/mnras/stw2076","year":"2016","external_id":{"arxiv":["1606.07435"]},"title":"The Lyα luminosity function at z= 5.7–6.6 and the steep drop of the faint end: Implications for reionization"},{"intvolume":"       808","status":"public","day":"28","type":"journal_article","publication":"The Astrophysical Journal","issue":"2","page":"139","scopus_import":"1","publisher":"IOP Publishing","language":[{"iso":"eng"}],"month":"07","article_type":"original","date_published":"2015-07-28T00:00:00Z","date_created":"2022-07-07T09:00:58Z","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."}],"author":[{"last_name":"Sobral","full_name":"Sobral, David","first_name":"David"},{"id":"7439a258-f3c0-11ec-9501-9df22fe06720","orcid":"0000-0003-2871-127X","full_name":"Matthee, Jorryt J","last_name":"Matthee","first_name":"Jorryt J"},{"first_name":"Behnam","full_name":"Darvish, Behnam","last_name":"Darvish"},{"first_name":"Daniel","full_name":"Schaerer, Daniel","last_name":"Schaerer"},{"last_name":"Mobasher","full_name":"Mobasher, Bahram","first_name":"Bahram"},{"first_name":"Huub","last_name":"Röttgering","full_name":"Röttgering, Huub"},{"first_name":"Sérgio","full_name":"Santos, Sérgio","last_name":"Santos"},{"first_name":"Shoubaneh","last_name":"Hemmati","full_name":"Hemmati, Shoubaneh"}],"keyword":["Space and Planetary Science","Astronomy and Astrophysics","dark ages","reionization","first stars – early universe – galaxies: evolution"],"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>","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.","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.","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>","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.","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>."},"publication_status":"published","publication_identifier":{"issn":["0004-637X"],"eissn":["1538-4357"]},"extern":"1","_id":"11519","quality_controlled":"1","oa_version":"Preprint","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.","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","arxiv":1,"article_processing_charge":"No","date_updated":"2022-08-18T10:30:13Z","oa":1,"volume":808,"title":"Evidence for PopIII-like stellar populations in the most luminous Lyα emitters at the epoch of reionisation: Spectroscopic confirmation","external_id":{"arxiv":["1504.01734"]},"year":"2015","doi":"10.1088/0004-637X/808/2/139","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1504.01734"}]},{"month":"05","date_published":"2014-05-21T00:00:00Z","article_type":"original","publisher":"Oxford University Press","scopus_import":"1","language":[{"iso":"eng"}],"date_created":"2022-07-14T12:33:24Z","day":"21","type":"journal_article","intvolume":"       440","status":"public","issue":"3","publication":"Monthly Notices of the Royal Astronomical Society","page":"2375-2387","year":"2014","doi":"10.1093/mnras/stu392","external_id":{"arxiv":["1402.6697"]},"title":"A 10 deg2 Lyman α survey at z=8.8 with spectroscopic follow-up: Strong constraints on the luminosity function and implications for other surveys","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1402.6697"}],"publication_status":"published","citation":{"ieee":"J. J. Matthee <i>et al.</i>, “A 10 deg2 Lyman α survey at z=8.8 with spectroscopic follow-up: Strong constraints on the luminosity function and implications for other surveys,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 440, no. 3. Oxford University Press, pp. 2375–2387, 2014.","apa":"Matthee, J. J., Sobral, D., Swinbank, A. M., Smail, I., Best, P. N., Kim, J.-W., … Fynbo, J. (2014). A 10 deg2 Lyman α survey at z=8.8 with spectroscopic follow-up: Strong constraints on the luminosity function and implications for other surveys. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/stu392\">https://doi.org/10.1093/mnras/stu392</a>","chicago":"Matthee, Jorryt J, David Sobral, A. M. Swinbank, Ian Smail, P. N. Best, Jae-Woo Kim, Marijn Franx, Bo Milvang-Jensen, and Johan Fynbo. “A 10 Deg2 Lyman α Survey at Z=8.8 with Spectroscopic Follow-up: Strong Constraints on the Luminosity Function and Implications for Other Surveys.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2014. <a href=\"https://doi.org/10.1093/mnras/stu392\">https://doi.org/10.1093/mnras/stu392</a>.","ama":"Matthee JJ, Sobral D, Swinbank AM, et al. A 10 deg2 Lyman α survey at z=8.8 with spectroscopic follow-up: Strong constraints on the luminosity function and implications for other surveys. <i>Monthly Notices of the Royal Astronomical Society</i>. 2014;440(3):2375-2387. doi:<a href=\"https://doi.org/10.1093/mnras/stu392\">10.1093/mnras/stu392</a>","mla":"Matthee, Jorryt J., et al. “A 10 Deg2 Lyman α Survey at Z=8.8 with Spectroscopic Follow-up: Strong Constraints on the Luminosity Function and Implications for Other Surveys.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 440, no. 3, Oxford University Press, 2014, pp. 2375–87, doi:<a href=\"https://doi.org/10.1093/mnras/stu392\">10.1093/mnras/stu392</a>.","ista":"Matthee JJ, Sobral D, Swinbank AM, Smail I, Best PN, Kim J-W, Franx M, Milvang-Jensen B, Fynbo J. 2014. A 10 deg2 Lyman α survey at z=8.8 with spectroscopic follow-up: Strong constraints on the luminosity function and implications for other surveys. Monthly Notices of the Royal Astronomical Society. 440(3), 2375–2387.","short":"J.J. Matthee, D. Sobral, A.M. Swinbank, I. Smail, P.N. Best, J.-W. Kim, M. Franx, B. Milvang-Jensen, J. Fynbo, Monthly Notices of the Royal Astronomical Society 440 (2014) 2375–2387."},"abstract":[{"text":"Candidate galaxies at redshifts of z ∼ 10 are now being found in extremely deep surveys, probing very small areas. As a consequence, candidates are very faint, making spectroscopic confirmation practically impossible. In order to overcome such limitations, we have undertaken the CF-HiZELS survey, which is a large-area, medium-depth near-infrared narrow-band survey targeted at z = 8.8 Lyman α (Lyα) emitters (LAEs) and covering 10 deg2 in part of the SSA22 field with the Canada–France–Hawaii Telescope (CFHT). We surveyed a comoving volume of 4.7 × 106 Mpc3 to a Lyα luminosity limit of 6.3 × 1043舁erg舁s−1. We look for Lyα candidates by applying the following criteria: (i) clear emission-line source, (ii) no optical detections (ugriz from CFHTLS), (iii) no visible detection in the optical stack (ugriz > 27), (iv) visually checked reliable NBJ and J detections and (v) J − K ≤ 0. We compute photometric redshifts and remove a significant amount of dusty lower redshift line-emitters at z ∼ 1.4 or 2.2. A total of 13 Lyα candidates were found, of which two are marked as strong candidates, but the majority have very weak constraints on their spectral energy distributions. Using follow-up observations with SINFONI/VLT, we are able to exclude the most robust candidates as LAEs. We put a strong constraint on the Lyα luminosity function at z ∼ 9 and make realistic predictions for ongoing and future surveys. Our results show that surveys for the highest redshift LAEs are susceptible of multiple contaminations and that spectroscopic follow-up is absolutely necessary.","lang":"eng"}],"keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: evolution","galaxies: high-redshift","cosmology: observations","dark ages","reionization","first stars"],"author":[{"id":"7439a258-f3c0-11ec-9501-9df22fe06720","first_name":"Jorryt J","orcid":"0000-0003-2871-127X","last_name":"Matthee","full_name":"Matthee, Jorryt J"},{"first_name":"David","full_name":"Sobral, David","last_name":"Sobral"},{"first_name":"A. M.","last_name":"Swinbank","full_name":"Swinbank, A. M."},{"first_name":"Ian","full_name":"Smail, Ian","last_name":"Smail"},{"first_name":"P. N.","last_name":"Best","full_name":"Best, P. N."},{"last_name":"Kim","full_name":"Kim, Jae-Woo","first_name":"Jae-Woo"},{"first_name":"Marijn","last_name":"Franx","full_name":"Franx, Marijn"},{"last_name":"Milvang-Jensen","full_name":"Milvang-Jensen, Bo","first_name":"Bo"},{"last_name":"Fynbo","full_name":"Fynbo, Johan","first_name":"Johan"}],"arxiv":1,"oa":1,"volume":440,"date_updated":"2022-08-19T08:30:30Z","article_processing_charge":"No","_id":"11583","publication_identifier":{"issn":["0035-8711"],"eissn":["1365-2966"]},"extern":"1","acknowledgement":"We thank the anonymous referee for the comments and suggestions which improved both the quality and clarity of this work. DS acknowledges financial support from the Netherlands Organisation for Scientific Research (NWO) through a Veni fellowship. IRS acknowledges support from STFC (ST/I001573/1), a Leverhulme Fellowship, the ERC Advanced Investigator programme DUSTYGAL 321334 and a Royal Society/Wolfson Merit Award. PNB acknowledges support from the Leverhulme Trust. JWK acknowledges the support from the Creative Research Initiative Program, no. 2008- 0060544, of the National Research Foundation of Korea (NRF) funded by the Korean government (MSIP). JPUF and BMJ acknowledge support from the ERC-StG grant EGGS-278202. The Dark Cosmology Centre is funded by the Danish National Research Foundation. This work is based in part on data obtained as part of the UKIRT Infrared Deep Sky Survey. 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 l’Univers 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. This work was only possible due to OPTICON/FP7 and the access that it granted to the CFHT telescope. The authors also wish to acknowledge the CFHTLS and UKIDSS surveys for their excellent legacy and complementary value – without such high-quality data sets, this research would not have been possible.","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","quality_controlled":"1","oa_version":"Preprint"}]
