2015/03/31 by Ali Ahmad Khostovan, David Sobral, Bahram Mobasher +5 · 1 citation
Physics and Astronomy · #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stv1474
24 pages, 14 figures, 7 Tables, MNRAS accepted
arxiv created 2015/07/13 · arxiv updated 2015/07/15
We investigate the evolution of the Hβ+[OIII] and [OII] luminosity functions from z ∼ 0.8 to ∼5 in four redshift slices per emission line using data from the High-\it z Emission Line Survey (HiZELS). This is the first time that the Hβ+[OIII] and [OII] luminosity functions have been studied at these redshifts in a self-consistent analysis. This is also the largest sample of [OII] and Hβ+[OIII] emitters (3475 and 3298 emitters, respectively) in this redshift range, with large co-moving volumes ∼ 1 × 106 Mpc-3 in two independent volumes (COSMOS and UDS), greatly reducing the effects of cosmic variance. The emitters were selected by a combination of photometric redshift and color-color selections, as well as spectroscopic follow-up, including recent spectroscopic observations using DEIMOS and MOSFIRE on the Keck Telescopes and FMOS on Subaru. We find a strong increase in L_⋆ and a decrease in ϕ_⋆ for both Hβ+[OIII] and [OII] emitters. We derive the [OII] star-formation history of the Universe since z∼5 and find that the cosmic SFRD rises from z ∼ 5 to ∼ 3 and then drops towards z ∼ 0. We also find that our star-formation history is able to reproduce the evolution of the stellar mass density up to z∼ 5 based only on a single tracer of star-formation. When comparing the Hβ+[OIII] SFRDs to the [OII] and Hα SFRD measurements in the literature, we find that there is a remarkable agreement, suggesting that the Hβ+[OIII] sample is dominated by star-forming galaxies at high-z rather than AGNs.