The VIMOS VLT Deep Survey. The Assembly History of the Stellar Mass in Galaxies: from the Young to the Old Universe

L. Pozzetti (1) , M. Bolzonella (1) , F. Lamareille (2, 3) , G. Zamorani (1) , P. Franzetti (1) , O. Le Fevre (4) , A. Iovino (1) , S. Temporin (5) , O. Ilbert (4) , S. Arnouts (4) , S. Charlot (6) , J. Brinchmann (1) , E. Zucca (1) , L. Tresse (4) , M. Scodeggio (1) , L. Guzzo (1) , D. Bottini (1) , B. Garilli (1) , V. Le Brun (4) , D. Maccagni (1) , J. P. Picat (2, 7) , R. Scaramella (1) , G. Vettolani (1) , A. Zanichelli (1) , C. Adami (4) , S. Bardelli (1) , A. Cappi (1) , P. Ciliegi (1) , T. Contini (2) , Sylvie Foucaud (8) , I. Gavignaud (2, 7, 9) , H. J. Mccracken (6) , B. Marano (1) , Christian Marinoni (4) , A. Mazure (4) , B. Meneux (4) , R. Merighi (1) , S. Paltani (4) , R. Pellò (2, 7) , A. Pollo (4) , M. Radovich (1) , M. Bondi (1) , A. Bongiorno (1) , O. Cucciati (1) , S. de La Torre (1) , L. Gregorini (1) , Y. Mellier (6, 10) , P. Merluzzi (1) , D. Vergani (1) , C. J. Walcher (4)

1 AUTRES
2 LATT - Laboratoire d'Astrophysique de l'Observatoire Midi-Pyrénées
3 OP - Observatoire de Paris - Site de Paris
4 LAM - Laboratoire d'Astrophysique de Marseille
5 DAPNIA - Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée
6 IAP - Institut d'Astrophysique de Paris
7 UMS 831 - Services communs OMP
8 Axe 1 : procédés céramiques
9 ESO - European Southern Observatory
10 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique

We present a detailed analysis of the Galaxy Stellar Mass Function of galaxies up to z=2.5 as obtained from the VVDS. We estimate the stellar mass from broad-band photometry using 2 different assumptions on the galaxy star formation history and show that the addition of secondary bursts to a continuous star formation history produces systematically higher (up to 40%) stellar masses. At low redshift (z=0.2) we find a substantial population of low-mass galaxies (<10^9 Msun) composed by faint blue galaxies (MI-MK=0.3). In general the stellar mass function evolves slowly up to z=0.9 and more significantly above this redshift. Conversely, a massive tail is present up to z=2.5. We find a decline with redshift of the overall number density of galaxies for all masses (59+-5% for M>10^8 Msun at z=1), and a mild mass-dependent average evolution (`mass-downsizing'). In particular our data are consistent with mild/negligible (<30%) evolution up to z=0.7 for massive galaxies (>6x10^10 Msun). For less massive systems the no-evolution scenario is excluded. A large fraction (>=50%) of massive galaxies have been already assembled and converted most of their gas into stars at z=1, ruling out the `dry mergers' as the major mechanism of their assembly history below z=1. This fraction decreases to 33% at z=2. Low-mass systems have decreased continuously in number and mass density (by a factor up to 4) from the present age to z=2, consistently with a prolonged mass assembly also at z<1. At z>1.5 we note a flattening in the number and mass density of massive galaxies, compared to previous surveys, produced by a population with extremely red colours (MI-MK=0.8).

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Astrophysique [astro-ph]

L. Pozzetti, M. Bolzonella, F. Lamareille, G. Zamorani, P. Franzetti, et al.. The VIMOS VLT Deep Survey. The Assembly History of the Stellar Mass in Galaxies: from the Young to the Old Universe. Astronomy and Astrophysics - A&A, 2007, 474, pp.443. ⟨hal-00149223⟩