Stellar mass to halo mass relation from galaxy clustering in VUDS: a high star formation efficiency at z ≃ 3^⋆

¹ Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France
e-mail: anna.durkalec@lam.fr
² INAF–Osservatorio Astronomico di Bologna, via Ranzani,1, 40127 Bologna, Italy
³ INAF–IASF, via Bassini 15, 20133 Milano, Italy
⁴ INAF–Osservatorio Astronomico di Roma, via di Frascati 33, 00040 Monte Porzio Catone, Italy
⁵ University of Bologna, Department of Physics and Astronomy (DIFA), V.le Berti Pichat 6/2, 40127 Bologna, Italy
⁶ INAF–IASF Bologna, via Gobetti 101, 40129 Bologna, Italy
⁷ Institut d’Astrophysique de Paris, UMR7095 CNRS, Université Pierre et Marie Curie, 98bis Boulevard Arago, Paris, France
⁸ Institut de Recherche en Astrophysique et Planétologie – IRAP, CNRS, Université de Toulouse, UPS-OMP, 14 avenue E. Belin, 31400 Toulouse, France
⁹ Department of Astronomy, University of Geneva, ch. d’Écogia 16, 1290 Versoix, Switzerland
¹⁰ Geneva Observatory, University of Geneva, ch. des Maillettes 51, 1290 Versoix, Switzerland
¹¹ Centro de Estudios de Física del Cosmos de Aragón, 44001 Teruel, Spain
¹² Department of Astronomy, California Institute of Technology, 1200 E. California Blvd., MC 249–17, Pasadena, USA
¹³ Astronomy Department, University of Massachusetts, Amherst, MA 01003, USA
¹⁴ Max-Planck-Institut für Extraterrestrische Physik, Postfach 1312, 85741 Garching bei München, Germany
¹⁵ Research Center for Space and Cosmic Evolution, Ehime University, Bunkyo-cho 2-5, 790-8577 Matsuyama, Japan
¹⁶ SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, EH9 3HJ, UK
¹⁷ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
¹⁸ Instituto de Fisica y Astronomia, Facultad de Ciencias, Universidad de Valparaiso, Av. Gran Bretana 1111, Casilla 5030 Valparaiso, Chile
¹⁹ Astronomical Observatory of the Jagiellonian University, Orla 171, 30-001 Cracow, Poland
²⁰ National Centre for Nuclear Research, ul. Hoza 69, 00-681 Warszawa, Poland

Received: 17 December 2014
Accepted: 27 February 2015

Abstract

The relation between the galaxy stellar mass M_⋆ and the dark matter halo mass M_h gives important information on the efficiency in forming stars and assembling stellar mass in galaxies. We present measurements of the ratio of stellar mass to halo mass (SMHR) at redshifts 2 < z < 5, obtained from the VIMOS Ultra Deep Survey. We use halo occupation distribution (HOD) modelling of clustering measurements on ~3000 galaxies with spectroscopic redshifts to derive the dark matter halo mass M_h, and spectral energy density fitting over a large set of multi-wavelength data to derive the stellar mass M_⋆ and compute the SMHR = M_⋆/M_h. We find that the SMHR ranges from 1% to 2.5% for galaxies with M_⋆ = 1.3 × 10⁹ M_⊙ to M_⋆ = 7.4 × 10⁹ M_⊙ in DM halos with M_h = 1.3 × 10¹¹ M_⊙ to M_h = 3 × 10¹¹ M_⊙. We derive the integrated star formation efficiency (ISFE) of these galaxies and find that the star formation efficiency is a moderate 6−9% for lower mass galaxies, while it is relatively high at 16% for galaxies with the median stellar mass of the sample ~ 7 × 10⁹ M_⊙. The lower ISFE at lower masses may indicate that some efficient means of suppressing star formation is at work (like SNe feedback), while the high ISFE for the average galaxy at z ~ 3 indicates that these galaxies efficiently build up their stellar mass at a key epoch in the mass assembly process. Based on our results, we propose a possible scenario in which the average massive galaxy at z ~ 3 begins to experience truncation of its star formation within a few million years.