The VIMOS-VLT Deep Survey. Galaxy luminosity function per morphological type up to z = 1.2
Bondi, M.; Maccagni, D.; Ilbert, O.; Buat, V.; Burgarella, D.; Paltani, S.; Adami, C.; Bolzonella, M.; Ripepi, V.; Arnouts, S.; McCracken, H. J.; Rizzo, D.; Zanichelli, A.; Radovich, M.; Scaramella, R.; Zamorani, G.; Le Fèvre, O.; Garilli, B.; Pozzetti, L.; Bardelli, S.; Zucca, E.; Cappi, A.; Charlot, S.; Mazure, A.; Meneux, B.; Scodeggio, M.; Bongiorno, A.; Pello, R.; Contini, T.; Tresse, L.; Mellier, Y.; Franzetti, P.; Iovino, A.; Le Brun, V.; Marinoni, C.; Pollo, A.; Merluzzi, P.; Ciliegi, P.; Busarello, G.; Guzzo, L.; Vettolani, G.; Bottini, D.; Marano, B.; Foucaud, S.; Arnaboldi, M.; Gavignaud, I.; Lauger, S.; Picat, J. -P.; Mathez, G.; Merighi, R.
France, Italy, Germany
Abstract
Aims.We have computed the evolution of the rest-frame B-band luminosity function (LF) for bulge and disk-dominated galaxies since z=1.2.
Methods: .We use a sample of 605 spectroscopic redshifts with IAB≤ 24 in the Chandra Deep Field South from the VIMOS-VLT Deep Survey, 3555 galaxies with photometric redshifts from the COMBO-17 multi-color data, coupled with multi-color HST/ACS images from the Great Observatories Origin Deep Survey. We split the sample in bulge- and disk-dominated populations on the basis of asymmetry and concentration parameters measured in the rest-frame B-band.
Results: .We find that at z=0.4-0.8, the LF slope is significantly steeper for the disk-dominated population (α=-1.19 ± 0.07) compared to the bulge-dominated population (α=-0.53 ± 0.13). The LF of the bulge-dominated population is composed of two distinct populations separated in rest-frame color: 68% of red (B-I)AB>0.9 and bright galaxies showing a strongly decreasing LF slope α=+0.55 ± 0.21, and 32% of blue (B-I)AB<0.9 and more compact galaxies which populate the LF faint-end. We observe that red bulge-dominated galaxies are already well in place at z≃1, but the volume density of this population is increasing by a factor 2.7 between z∼ 1 and z∼ 0.6. It may be related to the building-up of massive elliptical galaxies in the hierarchical scenario. In addition, we observe that the blue bulge-dominated population is dimming by 0.7 mag between z∼ 1 and z∼ 0.6. Galaxies in this faint and more compact population could possibly be the progenitors of the local dwarf spheroidal galaxies.