Nadolny, JakubLara López, Maritza A.Cerviño, MiguelBongiovanni, ÁngelCepa, Jordide Diego, José A.Pérez García, Ana MaríaPérez Martínez, RicardoSánchez Portal, MiguelAlfaro, EmilioCastañeda, Héctor O.Gallego Maestro, JesúsGonzález, J. JesúsGonzález-Serrano, J. IgnacioPadilla Torres, Carmen P.Pintos-Castro, IrenePović, Mirjana2026-01-262026-01-262020-04Nadolny, Jakub, et al. «The OTELO survey: Nature and mass-metallicity relation for H α emitters at z ∼ 0.4». Astronomy & Astrophysics, vol. 636, abril de 2020, p. A84. DOI.org (Crossref), https://doi.org/10.1051/0004-6361/201936205.0004-636110.1051/0004-6361/201936205https://hdl.handle.net/20.500.14352/130985©ESO 2020Context. The OSIRIS Tunable Filter Emission Line Object (OTELO) survey is a very deep, blind exploration of a selected region of the Extended Groth Strip and is designed for finding emission-line sources (ELSs). The survey design, observations, data reduction, astrometry, and photometry, as well as the correlation with ancillary data used to obtain a final catalogue, including photo-z estimates and a preliminary selection of ELS, were described in a previous contribution. Aims. Here, we aim to determine the main properties and luminosity function (LF) of the [O III] ELS sample of OTELO as a scientific demonstration of its capabilities, advantages, and complementarity with respect to other surveys. Methods. The selection and analysis procedures of ELS candidates obtained using tunable filter pseudo-spectra are described. We performed simulations in the parameter space of the survey to obtain emission-line detection probabilities. Relevant characteristics of [O III] emitters and the LF ([O III]), including the main selection biases and uncertainties, are presented. Results. From 541 preliminary emission-line source candidates selected around z & x2004;=& x2004;0.8, a total of 184 sources were confirmed as [O III] emitters. Consistent with simulations, the minimum detectable line flux and equivalent width in this ELS sample are similar to 5 x 10(-19) erg s(-1) cm(2) and similar to 6 angstrom, respectively. We are able to constrain the faint-end slope (alpha & x2004;=& x2004;-1.03 +/- 0.08) of the observed LF ([O III]) at a mean redshift of z & x2004;=& x2004;0.83. This LF reaches values that are approximately ten times lower than those from other surveys. The vast majority (84%) of the morphologically classified [O III] ELSs are disc-like sources, and 87% of this sample is comprised of galaxies with stellar masses of M-& x22c6;& x2004;< & x2004;10(10) M-circle dot.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/journal article1432-0746https://doi.org/10.1051/0004-6361/201936205https://www.aanda.org/articles/aa/full_html/2020/04/aa36205-19/aa36205-19.htmlhttps://arxiv.org/abs/2003.07154open access52-33Galaxies-evolutionGalaxies-formationGalaxies-fundamental parametersGalaxies-star formationGalaxies- structureAstrofísica21 Astronomía y Astrofísica