{"publication":"Monthly Notices of the Royal Astronomical Society","publication_status":"published","abstract":[{"lang":"eng","text":"While traditionally associated with active galactic nuclei (AGN), the properties of the C II] (λ = 2326 Å), C III] (λ, λ = 1907, 1909 Å) and C IV (λ, λ = 1549, 1551 Å) emission lines are still uncertain as large, unbiased samples of sources are scarce. We present the first blind, statistical study of C II], C III] and C IV emitters at z ∼ 0.68, 1.05, 1.53, respectively, uniformly selected down to a flux limit of ∼4 × 10−17 erg s−1 cm−1 through a narrow-band survey covering an area of ∼1.4 deg2 over COSMOS and UDS. We detect 16 C II], 35 C III] and 17 C IV emitters, whose nature we investigate using optical colours as well as Hubble Space Telescope (HST), X-ray, radio and far-infrared data. We find that z ∼ 0.7 C II] emitters are consistent with a mixture of blue (UV slope β = −2.0 ± 0.4) star-forming (SF) galaxies with discy HST structure and AGN with Seyfert-like morphologies. Bright C II] emitters have individual X-ray detections as well as high average black hole accretion rates (BHARs) of ∼0.1 M⊙ yr−1. C III] emitters at z ∼ 1.05 trace a general population of SF galaxies, with β = −0.8 ± 1.1, a variety of optical morphologies, including isolated and interacting galaxies and low BHAR (<0.02 M⊙ yr−1). Our C IV emitters at z ∼ 1.5 are consistent with young, blue quasars (β ∼ −1.9) with point-like optical morphologies, bright X-ray counterparts and large BHAR (0.8  M⊙ yr−1). We also find some surprising C II], C III] and C IV emitters with rest-frame equivalent widths (EWs) that could be as large as 50–100 Å. AGN or spatial offsets between the UV continuum stellar disc and the line-emitting regions may explain the large EW. These bright C II], C III] and C IV emitters are ideal candidates for spectroscopic follow-up to fully unveil their nature."}],"doi":"10.1093/mnras/stx1712","author":[{"last_name":"Stroe","full_name":"Stroe, Andra","first_name":"Andra"},{"full_name":"Sobral, David","first_name":"David","last_name":"Sobral"},{"id":"7439a258-f3c0-11ec-9501-9df22fe06720","last_name":"Matthee","orcid":"0000-0003-2871-127X","first_name":"Jorryt J","full_name":"Matthee, Jorryt J"},{"last_name":"Calhau","first_name":"João","full_name":"Calhau, João"},{"last_name":"Oteo","first_name":"Ivan","full_name":"Oteo, Ivan"}],"_id":"11566","publication_identifier":{"issn":["0035-8711"],"eissn":["1365-2966"]},"volume":471,"date_updated":"2022-08-19T07:59:57Z","type":"journal_article","extern":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa":1,"page":"2558-2574","status":"public","external_id":{"arxiv":["1703.10169"]},"citation":{"apa":"Stroe, A., Sobral, D., Matthee, J. J., Calhau, J., &#38; Oteo, I. (2017). A 1.4 deg2 blind survey for C II], C III] and C IV at z ∼ 0.7–1.5 – I. Nature, morphologies and equivalent widths . <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/stx1712\">https://doi.org/10.1093/mnras/stx1712</a>","ista":"Stroe A, Sobral D, Matthee JJ, Calhau J, Oteo I. 2017. A 1.4 deg2 blind survey for C II], C III] and C IV at z ∼ 0.7–1.5 – I. Nature, morphologies and equivalent widths . Monthly Notices of the Royal Astronomical Society. 471(3), 2558–2574.","chicago":"Stroe, Andra, David Sobral, Jorryt J Matthee, João Calhau, and Ivan Oteo. “A 1.4 Deg2 Blind Survey for C II], C III] and C IV at z ∼ 0.7–1.5 – I. Nature, Morphologies and Equivalent Widths .” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2017. <a href=\"https://doi.org/10.1093/mnras/stx1712\">https://doi.org/10.1093/mnras/stx1712</a>.","ieee":"A. Stroe, D. Sobral, J. J. Matthee, J. Calhau, and I. Oteo, “A 1.4 deg2 blind survey for C II], C III] and C IV at z ∼ 0.7–1.5 – I. Nature, morphologies and equivalent widths ,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 471, no. 3. Oxford University Press, pp. 2558–2574, 2017.","short":"A. Stroe, D. Sobral, J.J. Matthee, J. Calhau, I. Oteo, Monthly Notices of the Royal Astronomical Society 471 (2017) 2558–2574.","ama":"Stroe A, Sobral D, Matthee JJ, Calhau J, Oteo I. A 1.4 deg2 blind survey for C II], C III] and C IV at z ∼ 0.7–1.5 – I. Nature, morphologies and equivalent widths . <i>Monthly Notices of the Royal Astronomical Society</i>. 2017;471(3):2558-2574. doi:<a href=\"https://doi.org/10.1093/mnras/stx1712\">10.1093/mnras/stx1712</a>","mla":"Stroe, Andra, et al. “A 1.4 Deg2 Blind Survey for C II], C III] and C IV at z ∼ 0.7–1.5 – I. Nature, Morphologies and Equivalent Widths .” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 471, no. 3, Oxford University Press, 2017, pp. 2558–74, doi:<a href=\"https://doi.org/10.1093/mnras/stx1712\">10.1093/mnras/stx1712</a>."},"date_created":"2022-07-12T12:33:16Z","month":"11","article_processing_charge":"No","acknowledgement":"We would like to thank the anonymous referee for her/his valuable input that helped improve the clarity and interpretation of our results. DS acknowledges financial support from the Netherlands Organisation for Scientific research (NWO), through a Veni fellowship. IO acknowledges support from the European Research Council in the form of the Advanced Investigator Programme, 321302, COSMICISM. CALYMHA data are based on observations made with the Isaac Newton Telescope (proposals 13AN002, I14AN002, 088-INT7/14A, I14BN006, 118-INT13/14B, I15AN008) 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 Astrofísica de Canarias. Also based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under ESO programme IDs 098.A-0819 and 179.A-2005. We are grateful to E. L. Wright and J. Schombert for their cosmology calculator. We would like to thank the authors of NUMPY (van der Walt et al. 2011), SCIPY (Jones et al. 2001), MATPLOTLIB (Hunter 2007) and ASTROPY (Astropy Collaboration et al. 2013) for making these packages publicly available. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is ","issue":"3","oa_version":"Preprint","main_file_link":[{"url":"https://arxiv.org/abs/1703.10169","open_access":"1"}],"title":"A 1.4 deg2 blind survey for C II], C III] and C IV at z ∼ 0.7–1.5 – I. Nature, morphologies and equivalent widths ","quality_controlled":"1","scopus_import":"1","intvolume":"       471","language":[{"iso":"eng"}],"date_published":"2017-11-01T00:00:00Z","article_type":"original","publisher":"Oxford University Press","year":"2017","day":"01","keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: active","galaxies: high-redshift","quasars: emission lines","galaxies: star formation","cosmology: observations"]}