{"title":"The most luminous H α emitters at z ∼ 0.8–2.23 from HiZELS: Evolution of AGN and star-forming galaxies","publication_status":"published","publication":"Monthly Notices of the Royal Astronomical Society","abstract":[{"lang":"eng","text":"We use new near-infrared spectroscopic observations to investigate the nature and evolution of the most luminous Hα emitters at z ∼ 0.8–2.23, which evolve strongly in number density over this period, and compare them to more typical Hα emitters. We study 59 luminous Hα emitters with LHα > L∗Hα, roughly equally split per redshift slice at z ∼ 0.8, 1.47 and 2.23 from the HiZELS and CF-HiZELS surveys. We find that, overall, 30 ± 8 per cent are active galactic nuclei [AGNs; 80 ± 30 per cent of these AGNs are broad-line AGNs, BL-AGNs], and we find little to no evolution in the AGN fraction with redshift, within the errors. However, the AGN fraction increases strongly with Hα luminosity and correlates best with LHα/L∗Hα(z). While LHα ≤ L∗Hα(z) Hα emitters are largely dominated by star-forming galaxies (>80 per cent), the most luminous Hα emitters (LHα>10L∗Hα(z)) at any cosmic time are essentially all BL-AGN. Using our AGN-decontaminated sample of luminous star-forming galaxies, and integrating down to a fixed Hα luminosity, we find a factor of ∼1300 evolution in the star formation rate density from z = 0 to 2.23. This is much stronger than the evolution from typical Hα star-forming galaxies and in line with the evolution seen for constant luminosity cuts used to select ‘ultraluminous’ infrared galaxies and/or sub-millimetre galaxies. By taking into account the evolution in the typical Hα luminosity, we show that the most strongly star-forming Hα-selected galaxies at any epoch (LHα>L∗Hα(z)) contribute the same fractional amount of ≈15 per cent to the total star formation rate density, at least up to z = 2.23."}],"doi":"10.1093/mnras/stw022","date_created":"2022-07-13T12:50:36Z","author":[{"first_name":"David","full_name":"Sobral, David","last_name":"Sobral"},{"last_name":"Kohn","first_name":"Saul A.","full_name":"Kohn, Saul A."},{"last_name":"Best","full_name":"Best, Philip N.","first_name":"Philip N."},{"first_name":"Ian","full_name":"Smail, Ian","last_name":"Smail"},{"full_name":"Harrison, Chris M.","first_name":"Chris M.","last_name":"Harrison"},{"full_name":"Stott, John","first_name":"John","last_name":"Stott"},{"last_name":"Calhau","full_name":"Calhau, João","first_name":"João"},{"first_name":"Jorryt J","full_name":"Matthee, Jorryt J","id":"7439a258-f3c0-11ec-9501-9df22fe06720","orcid":"0000-0003-2871-127X","last_name":"Matthee"}],"extern":"1","scopus_import":"1","article_type":"original","quality_controlled":"1","citation":{"short":"D. Sobral, S.A. Kohn, P.N. Best, I. Smail, C.M. Harrison, J. Stott, J. Calhau, J.J. Matthee, Monthly Notices of the Royal Astronomical Society 457 (2016) 1739–1752.","apa":"Sobral, D., Kohn, S. A., Best, P. N., Smail, I., Harrison, C. M., Stott, J., … Matthee, J. J. (2016). The most luminous H α emitters at z ∼ 0.8–2.23 from HiZELS: Evolution of AGN and star-forming galaxies. Monthly Notices of the Royal Astronomical Society. Oxford University Press. https://doi.org/10.1093/mnras/stw022","ama":"Sobral D, Kohn SA, Best PN, et al. The most luminous H α emitters at z ∼ 0.8–2.23 from HiZELS: Evolution of AGN and star-forming galaxies. Monthly Notices of the Royal Astronomical Society. 2016;457(2):1739-1752. doi:10.1093/mnras/stw022","mla":"Sobral, David, et al. “The Most Luminous H α Emitters at z ∼ 0.8–2.23 from HiZELS: Evolution of AGN and Star-Forming Galaxies.” Monthly Notices of the Royal Astronomical Society, vol. 457, no. 2, Oxford University Press, 2016, pp. 1739–52, doi:10.1093/mnras/stw022.","chicago":"Sobral, David, Saul A. Kohn, Philip N. Best, Ian Smail, Chris M. Harrison, John Stott, João Calhau, and Jorryt J Matthee. “The Most Luminous H α Emitters at z ∼ 0.8–2.23 from HiZELS: Evolution of AGN and Star-Forming Galaxies.” Monthly Notices of the Royal Astronomical Society. Oxford University Press, 2016. https://doi.org/10.1093/mnras/stw022.","ista":"Sobral D, Kohn SA, Best PN, Smail I, Harrison CM, Stott J, Calhau J, Matthee JJ. 2016. The most luminous H α emitters at z ∼ 0.8–2.23 from HiZELS: Evolution of AGN and star-forming galaxies. Monthly Notices of the Royal Astronomical Society. 457(2), 1739–1752.","ieee":"D. Sobral et al., “The most luminous H α emitters at z ∼ 0.8–2.23 from HiZELS: Evolution of AGN and star-forming galaxies,” Monthly Notices of the Royal Astronomical Society, vol. 457, no. 2. Oxford University Press, pp. 1739–1752, 2016."},"date_published":"2016-04-01T00:00:00Z","date_updated":"2022-08-19T08:15:21Z","acknowledgement":"The authors would like to thank the anonymous reviewer for the many helpful comments and suggestions which greatly improved the clarity and quality of this work. DS and SAK acknowledge financial support from the Netherlands Organisation for Scientific research (NWO) through a Veni fellowship. DS also acknowledges funding from FCT through an FCT Investigator Starting Grant and Start-up Grant (IF/01154/2012/CP0189/CT0010) and from FCT grant PEst-OE/FIS/UI2751/2014. Part of this project was undertaken during the inaugural Leiden/ESA Astrophysics Program for Summer Students (LEAPS). IRS acknowledges support from STFC (ST/L00075X/1), the ERC Advanced Investigator programme DUSTYGAL 321334 and a Royal Society/Wolfson merit award. CH acknowledges support from STFC. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 087.A-0337 and ID 089.A-0965. Also based on data from the Telescopio Nazionale Galileo, with time awarded through OPTICON programmes 2011A/026 and 2012A020 and the William Herschel Telescope under programme W12BN007. The William Herschel Telescope is operated on the island of La Palma by the Isaac Newton Group in the Spanish\r\nObservatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. The authors wish to thank all the help given by the telescope staff from all the observatories used in this study: ESO staff in La Silla, and the TNG and WHT staff in La Palma. This publication makes use of data products from the Two Micron All-Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation.","oa":1,"keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: evolution","galaxies: high-redshift","cosmology: observations"],"oa_version":"Preprint","arxiv":1,"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","status":"public","year":"2016","publication_identifier":{"issn":["0035-8711"],"eissn":["1365-2966"]},"type":"journal_article","article_processing_charge":"No","_id":"11576","publisher":"Oxford University Press","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1601.02266"}],"language":[{"iso":"eng"}],"external_id":{"arxiv":["1601.02266"]},"day":"01","issue":"2","volume":457,"month":"04","page":"1739-1752","intvolume":" 457"}