SHARDS: A Global View of the Star Formation Activity at z ~ 0.84 and z ~ 1.23
Barro, Guillermo; Pérez-González, Pablo G.; Koekemoer, Anton M.; Tresse, Laurence; Daddi, Emanuele; Eliche-Moral, M. Carmen; Cava, Antonio; Cenarro, A. Javier; Alonso-Herrero, Almudena; Charlot, Stephane; Vidal-García, Alba; Huertas-Company, Marc; Esquej, Pilar; Hernán-Caballero, Antonio; Dessauges-Zavadsky, Miroslava; Rodríguez-Muñoz, Lucia; Cardiel, Nicolas; Ricciardelli, Elena; Alcalde Pampliega, Belen; Domínguez Sánchez, Helena; Espino-Briones, Nestor; Gallego, Jesus; Muñoz-Tunon, Casiana; Rodriguez-Espinosa, Jose M.; Villar, Victor
Switzerland, Spain, France, United States, Italy
Abstract
In this paper, we present a comprehensive analysis of star-forming galaxies (SFGs) at intermediate redshifts (z ∼ 1). We combine the ultra-deep optical spectro-photometric data from the Survey for High-z Absorption Red and Dead Sources (SHARDS) with deep UV-to-FIR observations in the GOODS-N field. Exploiting two of the 25 SHARDS medium-band filters, F687W17 and F823W17, we select [O ii] emission line galaxies at z ∼ 0.84 and z ∼ 1.23 and characterize their physical properties. Their rest-frame equivalent widths (EWrf([O ii])), line fluxes, luminosities, star formation rates (SFRs), and dust attenuation properties are investigated. The evolution of EWrf([O ii]) closely follows the SFR density evolution of the universe, with a trend of EWrf([O ii]) \propto (1 + z)3 up to redshift z ≃ 1, followed by a possible flattening. The SF properties of the galaxies selected on the basis of their [O ii] emission are compared with complementary samples of SFGs selected by their MIR and FIR emission, and also with a general mass-selected sample of galaxies at the same redshifts. We demonstrate observationally that the UVJ diagram (or, similarly, a cut in the specific SFR) is only partially able to distinguish the quiescent galaxies from the SFGs. The SFR-M* relation is investigated for the different samples, yielding a logarithmic slope ∼1, in good agreement with previous results. The dust attenuations derived from different SFR indicators (UV(1600), UV(2800), [O ii], IR) are compared and show clear trends with respect to both the stellar mass and total SFR, with more massive and highly star-forming galaxies being affected by stronger dust attenuation.