SARCS strong-lensing galaxy groups I. Optical, weak lensing, and scaling laws - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Article Dans Une Revue Astronomy and Astrophysics - A&A Année : 2013

SARCS strong-lensing galaxy groups I. Optical, weak lensing, and scaling laws

G. Foex
  • Fonction : Auteur
V. Motta
  • Fonction : Auteur
T. Verdugo
  • Fonction : Auteur
A. More
  • Fonction : Auteur
R. Cabanac
  • Fonction : Auteur
R. Gavazzi
R. P. Munoz
  • Fonction : Auteur

Résumé

We present the weak-lensing and optical analysis of the SL2S-ARCS (SARCS) sample of strong-lensing candidates. The sample is based on the Strong Lensing Legacy Survey (SL2S), a systematic search of strong-lensing systems in the photometric Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). The SARCS sample focusses on arc-like features and is designed to contain mostly galaxy groups. We briefly present the weak-lensing methodology that we used to estimate the mass of the SARCS objects. Among 126 candidates, we obtained a weak-lensing detection (at the 1 sigma level) for 89 objects with velocity dispersions of the singular isothermal sphere mass model (SIS) ranging from sigma(SIS) similar to 350 km s(-1) to similar to 1000 km s(-1) with an average value of sigma(SIS) similar to 600 km s(-1), corresponding to a rich galaxy group (or poor cluster). From the galaxies belonging to the bright end of the group's red sequence (M-i \textless -21), we derived the optical properties of the SARCS candidates. We obtained typical richnesses of N similar to 5-15 galaxies and optical luminosities of L similar to 0.5-1.5 x 10(12) L-circle dot (within a radius of 0.5 Mpc). We used these galaxies to compute luminosity density maps, from which a morphological classification reveals that a large fraction of the sample (similar to 45%) are groups with a complex light distribution, either elliptical or multi-modal, suggesting that these objects are dynamically young structures. We finally combined the lensing and optical analyses to define a sample of the 80 most secure group candidates, i.e. weak-lensing detection and over-density at the lens position in the luminosity map, to remove false detections and galaxy-scale systems from the initial sample. We use this reduced sample to probe the optical scaling relations in combination with a sample of massive galaxy clusters. We detect the expected correlations over the probed range in mass with a typical scatter of similar to 25% in sigma(SIS) at a given richness or luminosity, making these scaling laws interesting mass proxies.

Dates et versions

hal-01439499 , version 1 (18-01-2017)

Identifiants

Citer

G. Foex, V. Motta, M. Limousin, T. Verdugo, A. More, et al.. SARCS strong-lensing galaxy groups I. Optical, weak lensing, and scaling laws. Astronomy and Astrophysics - A&A, 2013, 559, ⟨10.1051/0004-6361/201321112⟩. ⟨hal-01439499⟩
113 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More