{"intvolume":"       463","language":[{"iso":"eng"}],"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1606.07435"}],"title":"The Lyα luminosity function at z= 5.7–6.6 and the steep drop of the faint end: Implications for reionization","quality_controlled":"1","scopus_import":"1","issue":"2","oa_version":"Preprint","keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: high-redshift","galaxies: luminosity function","mass function","cosmology: observations","dark ages","reionization","first stars"],"year":"2016","publisher":"Oxford University Press","article_type":"original","day":"01","date_published":"2016-12-01T00:00:00Z","volume":463,"date_updated":"2022-08-19T08:09:54Z","type":"journal_article","extern":"1","publication_identifier":{"issn":["0035-8711"],"eissn":["1365-2966"]},"doi":"10.1093/mnras/stw2076","author":[{"first_name":"Sérgio","full_name":"Santos, Sérgio","last_name":"Santos"},{"last_name":"Sobral","first_name":"David","full_name":"Sobral, David"},{"orcid":"0000-0003-2871-127X","first_name":"Jorryt J","full_name":"Matthee, Jorryt J","id":"7439a258-f3c0-11ec-9501-9df22fe06720","last_name":"Matthee"}],"_id":"11574","publication":"Monthly Notices of the Royal Astronomical Society","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."}],"article_processing_charge":"No","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.","citation":{"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>","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>.","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.","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.","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>","short":"S. Santos, D. Sobral, J.J. Matthee, Monthly Notices of the Royal Astronomical Society 463 (2016) 1678–1691."},"date_created":"2022-07-13T10:08:20Z","month":"12","page":"1678-1691","status":"public","external_id":{"arxiv":["1606.07435"]},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa":1}