The VIMOS Public Extragalactic Redshift Survey (VIPERS)

Environmental effects shaping the galaxy stellar mass function^⋆

¹ Aix-Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France
e-mail: iary.davidzon@lam.fr
² INAF–Osservatorio Astronomico di Bologna, via Ranzani 1, 40127, Bologna, Italy
³ Dipartimento di Fisica e Astronomia–Alma Mater Studiorum Università di Bologna, viale Berti Pichat 6/2, 40127 Bologna, Italy
⁴ INAF–Osservatorio Astronomico di Trieste, via G. B. Tiepolo 11, 34143 Trieste, Italy
⁵ Canada-France-Hawaii Telescope, 65–1238 Mamalahoa Highway, Kamuela, HI 96743, USA
⁶ INAF–Istituto di Astrofisica Spaziale e Fisica Cosmica Milano, via Bassini 15, 20133 Milano, Italy
⁷ INAF–Osservatorio Astronomico di Brera, via Brera 28, 20122 Milano, via E. Bianchi 46, 23807 Merate, Italy
⁸ Dipartimento di Fisica, Università di Milano-Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
⁹ INAF – Osservatorio Astronomico di Torino, 10025 Pino Torinese, Italy
¹⁰ Université de Toulon, CNRS, CPT, UMR 7332, 83957 La Garde, France
¹¹ Aix-Marseille Université, CNRS, CPT, UMR 7332, 13288 Marseille, France
¹² Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, via della Vasca Navale 84, 00146 Roma, Italy
¹³ INFN, Sezione di Roma Tre, via della Vasca Navale 84, 00146 Roma, Italy
¹⁴ INAF – Osservatorio Astronomico di Roma, via Frascati 33, 00040 Monte Porzio Catone (RM), Italy
¹⁵ Laboratoire Lagrange, UMR 7293, Université de Nice Sophia Antipolis, CNRS, Observatoire de la Côte d’Azur, 06300 Nice, France
¹⁶ Astronomical Observatory of the University of Geneva, Ch. d’Écogia 16, 1290 Versoix, Switzerland
¹⁷ Institut d’Astrophysique Spatiale, Université Paris-Sud, CNRS, UMR 8617, 91405 Orsay, France
¹⁸ Institute of Physics, Jan Kochanowski University, ul. Swietokrzyska 15, 25-406 Kielce, Poland
¹⁹ National Centre for Nuclear Research, ul. Hoza 69, 00-681 Warszawa, Poland
²⁰ INFN, Sezione di Bologna, viale Berti Pichat 6/2, 40127 Bologna, Italy
²¹ Institute d’Astrophysique de Paris, UMR 7095 CNRS, Université Pierre et Marie Curie, 98bis boulevard Arago, 75014 Paris, France
²² Astronomical Observatory of the Jagiellonian University, Orla 171, 30-001 Cracow, Poland
²³ Institute of Cosmology and Gravitation,Dennis Sciama Building, University of Portsmouth, Burnaby Road, Portsmouth, PO1 3FX  
²⁴ INAF–Istituto di Astrofisica Spaziale e Fisica Cosmica Bologna, via Gobetti 101, 40129 Bologna, Italy
²⁵ INAF–Istituto di Radioastronomia, via Gobetti 101, 40129 Bologna, Italy

Received: 5 August 2015
Accepted: 2 November 2015

Abstract

We exploit the first public data release of VIPERS to investigate environmental effects in the evolution of galaxies between z ~ 0.5 and 0.9. The large number of spectroscopic redshifts (more than 50 000) over an area of about 10 deg² provides a galaxy sample with high statistical power. The accurate redshift measurements (σ_z = 0.00047(1 + z_spec)) allow us to robustly isolate galaxies living in the lowest and highest density environments (δ< 0.7 and δ> 4, respectively) as defined in terms of spatial 3D density contrast δ. We estimate the stellar mass function of galaxies residing in these two environments and constrain the high-mass end (ℳ ≳ 10¹¹ ℳ_⊙) with unprecedented precision. We find that the galaxy stellar mass function in the densest regions has a different shape than was measured at low densities, with an enhancement of massive galaxies and a hint of a flatter (less negative) slope at z< 0.8. We normalise each mass function to the comoving volume occupied by the corresponding environment and relate estimates from different redshift bins. We observe an evolution of the stellar mass function of VIPERS galaxies in high densities, while the low-density one is nearly constant. We compare these results to semi-analytical models and find consistent environmental signatures in the simulated stellar mass functions. We discuss how the halo mass function and fraction of central/satellite galaxies depend on the environments considered, making intrinsic and environmental properties of galaxies physically coupled, hence difficult to disentangle. The evolution of our low-density regions is described well by the formalism introduced by Peng et al. (2010, ApJ, 721, 193), and is consistent with the idea that galaxies become progressively passive because of internal physical processes. The same formalism could also describe the evolution of the mass function in the high density regions, but only if a significant contribution from dry mergers is considered.