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.
The VIMOS-VLT Deep Survey. Galaxy luminosity function per morphological type up to z = 1.2 / Ilbert O.; Lauger S.; Tresse L.; Buat V.; Arnouts S.; Le Fèvre O.; Burgarella D.; Zucca E.; Bardelli S.; Zamorani G.; Bottini D.; Garilli B.; Le Brun V.; Maccagni D.; Picat J.-P.; Scaramella R.; Scodeggio M.; Vettolani G.; Zanichelli A.; Adami C.; Arnaboldi M.; Bolzonella M.; Cappi A.; Charlot S.; Contini T.; Foucaud S.; Franzetti P.; Gavignaud I.; Guzzo L.; Iovino A.; McCracken H. J.; Marano B.; Marinoni C.; Mathez G.; Mazure A.; Meneux B.; Merighi R.; Paltani S.; Pello R.; Pollo A.; Pozzetti L.; Radovich M.; Bondi M.; Bongiorno A.; Busarello G.; Ciliegi P.; Mellier Y.; Merluzzi P.; Ripepi V.; Rizzo D.. - In: ASTRONOMY & ASTROPHYSICS. - ISSN 0004-6361. - STAMPA. - 453:(2006), pp. 809-815. [10.1051/0004-6361:20053632]
The VIMOS-VLT Deep Survey. Galaxy luminosity function per morphological type up to z = 1.2
MARANO, BRUNO;BONGIORNO, ANGELA;
2006
Abstract
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
