Evolution of Balmer jump selected galaxies in the ALHAMBRA survey^⋆

¹ Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Avda. Vicuña Mackenna 4860, 782-0436 Macul Santiago Chile
e-mail: ptroncos@astro.puc.cl
² Centro de Astro-Ingeniería, Pontificia Universidad Católica de Chile, Avda. Vicuña Mackenna 4860, 782-0436 Macul, Santiago, Chile
³ Centro de Estudios de Física del Cosmos de Aragón, Plaza de San Juan 1, 44001 Teruel, Spain
⁴ Department of Physics and Astronomy, Siena College, 515 Loudon Road, Loudonville, NY 12211, USA
⁵ Max Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany
⁶ Instituto de Astrofísica de Andalucía (IAA-CSIC), Glorieta de la Astronomía, 18008 Granada, Spain
⁷ Instituto de Astrofísica de Canarias, Vía Láctea s/n, 38200, La Laguna, Tenerife, Spain
⁸ Departamento de Astrofísica, Facultad de Física, Universidad de La Laguna, 38206 La Laguna, Spain
⁹ Unidad Asociada Observatorio Astronómico (IFCA-UV), 46980 Paterna, Spain
¹⁰ Instituto de Física de Cantabria (CSIC-UC), 39005 Santander, Spain
¹¹ Observatori Astronòmic, Universitat de València, C/ Catedràtic José Beltrán 2, 46980 Paterna, Spain
¹² Departament d’Astronomia i Astrofísica, Universitat de València, 46100 Burjassot, Spain
¹³ GEPI, Observatoire de Paris, CNRS, Université Paris Diderot, 61, Avenue de l’Observatoire, 75014 Paris, France
¹⁴ Instituto de Física y Astronomía, Universidad de Valparaíso, Avda. Gran Bretaña 1111, Valparaíso, Chile
¹⁵ APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/lrfu, Observatoire de Paris, Sorbonne Paris Cité, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France

Received: 13 October 2015
Accepted: 30 January 2016

Abstract

Context. Samples of star-forming galaxies at different redshifts have been traditionally selected via color techniques. The ALHAMBRA survey was designed to perform a uniform cosmic tomography of the Universe, and we here exploit it to trace the evolution of these galaxies.

Aims. Our objective is to use the homogeneous optical coverage of the ALHAMBRA filter system to select samples of star-forming galaxies at different epochs of the Universe and study their properties.

Methods. We present a new color-selection technique, based on the models of spectral evolution convolved with the ALHAMBRA bands and the redshifted position of the Balmer jump to select star-forming galaxies in the redshift range 0.5 <z< 1.5. These galaxies are dubbed Balmer-jump Galaxies (BJGs). We applied the iSEDfit Bayesian approach to fit each detailed spectral energy distribution and determined star-formation rate (SFR), stellar mass, age, and absolute magnitudes. The mass of the halos in which these samples reside were found through a clustering analysis.

Results. Five volume-limited BJG subsamples with different mean redshifts are found to reside in halos of median masses ~10^{12.5 ± 0.2} M_⊙ slightly increasing toward z = 0.5. This increment is similar to numerical simulations results, which suggests that we trace the evolution of an evolving population of halos as they grow to reach a mass of ~10^{12.7 ± 0.1} at z = 0.5. The likely progenitors of our samples at z ~ 3 are Lyman-break galaxies, which at z ~ 2 would evolve into star-forming BzK galaxies, and their descendants in the local Universe are galaxies with luminosities of 1–3 L_∗. Hence, this allows us to follow the putative evolution of the SFR, stellar mass, and age of these galaxies.

Conclusions. From z ~ 1.0 to z ~ 0.5, the stellar mass of the volume-limited BJG samples changes almost not at all with redshift, suggesting that major mergers play a minor role in the evolution of these galaxies. The SFR evolution accounts for the small variations of stellar mass, suggesting that star formation and possible minor mergers are the main channels of mass assembly.