{"volume":458,"external_id":{"arxiv":["1602.02756"]},"article_type":"original","intvolume":"       458","date_updated":"2022-08-19T08:17:19Z","abstract":[{"text":"We present the first results from our CAlibrating LYMan α with Hα (CALYMHA) pilot survey at the Isaac Newton Telescope. We measure Lyα emission for 488 Hα selected galaxies at z = 2.23 from High-z Emission Line Survey in the COSMOS and UDS fields with a specially designed narrow-band filter (λc = 3918 Å, Δλ = 52 Å). We find 17 dual Hα-Lyα emitters [fLyα > 5 × 10−17 erg s−1 cm−2, of which five are X-ray active galactic nuclei (AGN)]. For star-forming galaxies, we find a range of Lyα escape fractions (fesc, measured with 3 arcsec apertures) from 2 to 30 per cent. These galaxies have masses from 3 × 108 M⊙ to 1011 M⊙ and dust attenuations E(B − V) = 0–0.5. Using stacking, we measure a median escape fraction of 1.6 ± 0.5 per cent (4.0 ± 1.0 per cent without correcting Hα for dust), but show that this depends on galaxy properties. The stacked fesc tends to decrease with increasing star formation rate and dust attenuation. However, at the highest masses and dust attenuations, we detect individual galaxies with fesc much higher than the typical values from stacking, indicating significant scatter in the values of fesc. Relations between fesc and UV slope are bimodal, with high fesc for either the bluest or reddest galaxies. We speculate that this bimodality and large scatter in the values of fesc is due to additional physical mechanisms such as outflows facilitating fesc for dusty/massive systems. Lyα is significantly more extended than Hα and the UV. fesc continues to increase up to at least 20 kpc (3σ, 40 kpc [2σ]) for typical star-forming galaxies and thus the aperture is the most important predictor of fesc.","lang":"eng"}],"status":"public","day":"01","quality_controlled":"1","acknowledgement":"We thank the anonymous referee for constructive comments and suggestions which have improved the quality of this work. JM acknowledges the support of a Huygens PhD fellowship from Leiden University. DS and JM acknowledge financial support from the Netherlands Organization for Scientific research (NWO) through a Veni fellowship, and DS from FCT through a FCT Investigator Starting Grant and Start-up Grant (IF/01154/2012/CP0189/CT0010) and from FCT grant PEst-OE/FIS/UI2751/2014. IO acknowledges support from the European Research Council (ERC) in the form of Advanced Investigator Programme, COSMICISM, 321302. HR acknowledges support from the ERC Advanced Investigator programme NewClusters 321271. IRS acknowledges support from STFC (ST/L00075X/1), the ERC Advanced Investigator programme DUSTYGAL 321334 and a Royal Society/Wolfson Merit Award. APA acknowledges support from the Fundac¸ao para a Ciencia e para a Tecnologia (FCT) through the Fellowship SFRH/BD/52706/2014.\r\nBased on observations made with the Isaac Newton Telescope (proposals 2013AN002, 2013BN008, 2014AC88, 2014AN002, 2014BN006, 2014BC118) 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 Astrof´ısica de Canarias. We acknowledge the tremendous work that has been done by both COSMOS and UKIDSS UDS/SXDF teams in assembling such large, state-ofthe-art multi-wavelength data sets over such wide areas, as those have been crucial for the results presented in this paper. The sample of HAEs is publicly available from Sobral et al. (2013).\r\nWe have benefited greatly from the publically 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 imaging tools SEXTRACTOR, SWARP and SCAMP (Bertin & Arnouts 1996; Bertin 2006, 2010) and the TOPCAT analysis program (Taylor 2005).","extern":"1","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1602.02756"}],"publisher":"Oxford University Press","scopus_import":"1","oa":1,"publication_status":"published","_id":"11578","doi":"10.1093/mnras/stw322","publication_identifier":{"eissn":["1365-2966"],"issn":["0035-8711"]},"month":"05","title":"The CALYMHA survey: Lyα escape fraction and its dependence on galaxy properties at z = 2.23","issue":"1","keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: evolution","galaxies: high-redshift","galaxies: ISM"],"oa_version":"Preprint","type":"journal_article","citation":{"short":"J.J. Matthee, D. Sobral, I. Oteo, P. Best, I. Smail, H. Röttgering, A. Paulino-Afonso, Monthly Notices of the Royal Astronomical Society 458 (2016) 449–467.","apa":"Matthee, J. J., Sobral, D., Oteo, I., Best, P., Smail, I., Röttgering, H., &#38; Paulino-Afonso, A. (2016). The CALYMHA survey: Lyα escape fraction and its dependence on galaxy properties at z = 2.23. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/stw322\">https://doi.org/10.1093/mnras/stw322</a>","ista":"Matthee JJ, Sobral D, Oteo I, Best P, Smail I, Röttgering H, Paulino-Afonso A. 2016. The CALYMHA survey: Lyα escape fraction and its dependence on galaxy properties at z = 2.23. Monthly Notices of the Royal Astronomical Society. 458(1), 449–467.","ama":"Matthee JJ, Sobral D, Oteo I, et al. The CALYMHA survey: Lyα escape fraction and its dependence on galaxy properties at z = 2.23. <i>Monthly Notices of the Royal Astronomical Society</i>. 2016;458(1):449-467. doi:<a href=\"https://doi.org/10.1093/mnras/stw322\">10.1093/mnras/stw322</a>","chicago":"Matthee, Jorryt J, David Sobral, Iván Oteo, Philip Best, Ian Smail, Huub Röttgering, and Ana Paulino-Afonso. “The CALYMHA Survey: Lyα Escape Fraction and Its Dependence on Galaxy Properties at z = 2.23.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2016. <a href=\"https://doi.org/10.1093/mnras/stw322\">https://doi.org/10.1093/mnras/stw322</a>.","ieee":"J. J. Matthee <i>et al.</i>, “The CALYMHA survey: Lyα escape fraction and its dependence on galaxy properties at z = 2.23,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 458, no. 1. Oxford University Press, pp. 449–467, 2016.","mla":"Matthee, Jorryt J., et al. “The CALYMHA Survey: Lyα Escape Fraction and Its Dependence on Galaxy Properties at z = 2.23.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 458, no. 1, Oxford University Press, 2016, pp. 449–67, doi:<a href=\"https://doi.org/10.1093/mnras/stw322\">10.1093/mnras/stw322</a>."},"publication":"Monthly Notices of the Royal Astronomical Society","date_created":"2022-07-14T08:51:37Z","year":"2016","article_processing_charge":"No","date_published":"2016-05-01T00:00:00Z","language":[{"iso":"eng"}],"author":[{"id":"7439a258-f3c0-11ec-9501-9df22fe06720","last_name":"Matthee","full_name":"Matthee, Jorryt J","first_name":"Jorryt J","orcid":"0000-0003-2871-127X"},{"last_name":"Sobral","full_name":"Sobral, David","first_name":"David"},{"full_name":"Oteo, Iván","first_name":"Iván","last_name":"Oteo"},{"last_name":"Best","full_name":"Best, Philip","first_name":"Philip"},{"last_name":"Smail","first_name":"Ian","full_name":"Smail, Ian"},{"first_name":"Huub","full_name":"Röttgering, Huub","last_name":"Röttgering"},{"last_name":"Paulino-Afonso","first_name":"Ana","full_name":"Paulino-Afonso, Ana"}],"page":"449-467","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87"}