The VIMOS-VLT Deep Survey: Evolution of the galaxy luminosity function up to z=2 in first epoch data

TL;DR

This study analyzes the evolution of galaxy luminosity functions up to redshift 2 across multiple bands, revealing significant brightening and density increases of bright galaxies over cosmic time.

Contribution

It introduces the application of the Algorithm for Luminosity Function (ALF) to VVDS data, providing detailed measurements of luminosity function evolution across five rest-frame bands.

Findings

Brightening of M* by 1.0-2.5 magnitudes from z=0.05 to z=2

Increase in bright galaxy density by factors of 1.5 to 2.6 up to z=1

Steepening of the faint-end slope by ~0.3 between z=0.05 and z=1

Abstract

We investigate the evolution of the galaxy luminosity function from the VIMOS-VLT Deep Survey (VVDS) from the present to z=2 in five (U, B, V, R and I) rest-frame band-passes. We use the first epoch VVDS deep sample of 11,034 spectra selected at 17.5 <= I_{AB} <= 24.0, on which we apply the Algorithm for Luminosity Function (ALF), described in this paper. We observe a substantial evolution with redshift of the global luminosity functions in all bands. From z=0.05 to z=2, we measure a brightening of the characteristic magnitude M* included in the magnitude range 1.8-2.5, 1.7-2.4, 1.2-1.9, 1.1-1.8 and 1.0-1.6 in the U, B, V, R and I rest-frame bands, respectively. We confirm this differential evolution of the luminosity function with rest-frame wavelength, from the measurement of the comoving density of bright galaxies (M < M*(z=0.1)). This density increases by a factor of around 2.6, 2.2, 1.8, 1.5, 1.5 between z=0.05 and z=1 in the U, B, V, R, I bands, respectively. We also measure a possible steepening of the faint-end slope of the luminosity functions, with \Delta\alpha ~ -0.3 between z=0.05 and z=1, similar in all bands.