The VIMOS VLT Deep Survey

Testing the gravitational instability paradigm at z ~ 1

¹ Centre de Physique Théorique, UMR 6207 CNRS-Université de Provence, Case 907, 13288 Marseille, France e-mail: marinoni@cpt.univ-mrs.fr
² INAF – Osservatorio Astronomico di Brera, via Brera 28, 20121 Milano, Italy
³ Max Planck Institut für extraterrestrische Physik, 85741 Garching, Germany
⁴ INAF – Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy
⁵ Laboratoire d'Astrophysique de Marseille, UMR 6110, BP8 Traverse du Siphon, 13012 Marseille, France
⁶ Astronomical Observatory of the Jagiellonian University, ul Orla 171, 30-244 Krakow, Poland
⁷ Institut d'Astrophysique de Paris, UMR 7095, 98 bis Bvd. Arago, 75014 Paris, France
⁸ INAF – Osservatorio Astronomico di Roma, via Osservatorio 2, 00040 Monteporzio Catone (Roma), Italy
⁹ INAF – IASF, via Bassini 15, 20133 Milano, Italy
¹⁰ LAT – Observatoire Midi-Pyrénées, UMR5572, 14 av. E. Belin, 31400 Toulouse, France
¹¹ INAF – Istituto di Radio-Astronomia, via Gobetti 101, 40129 Bologna, Italy
¹² School of Physics & Astronomy, University of Nottingham, University Park, Nottingham, NG72RD, UK
¹³ Astrophysical Institute Potsdam, An der Sternwarte 16, 14482, Potsdam, Germany
¹⁴ Institute for Astronomy, 2680 Woodlawn Dr., University of Hawaii, Honolulu, Hawaii, 96822, USA
¹⁵ Università di Bologna, Dipartimento di Astronomia, via Ranzani 1, 40127 Bologna, Italy
¹⁶ Integral Science Data Centre, ch. d'Écogia 16, 1290, Versoix, Switzerland
¹⁷ Geneva Observatory, ch. des Maillettes 51, 1290, Sauverny, Switzerland
¹⁸ INAF – Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy
¹⁹ Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762, Porto, Portugal
²⁰ Università di Milano-Bicocca, Dipartimento di Fisica, Piazza della scienza 3, 20126 Milano, Italy

Received: 22 October 2007
Accepted: 12 January 2008

Abstract

We have reconstructed the three-dimensional density fluctuation maps to using the distribution of galaxies observed in the VVDS-Deep survey. We use this overdensity field to measure the evolution of the probability distribution function and its lower-order moments over the redshift interval . We apply a self-consistent reconstruction scheme which includes a complete non-linear description of galaxy biasing and which has been thoroughly tested on realistic mock samples. We find that the variance and skewness of the galaxy distribution evolve over this redshift interval in a way that is remarkably consistent with predictions of first- and second-order perturbation theory. This finding confirms the standard gravitational instability paradigm over nearly 9 Gyr of cosmic time and demonstrates the importance of accounting for the non-linear component of galaxy biasing to consistently reproduce the higher-order moments of the galaxy distribution and their evolution.