The cluster of galaxies LCDCS-S001 - II. r′ and i′ photometry, morphological analysis and improved kinematic parameters

• Published in: Monthly notices of the Royal Astronomical Society 2012-05, Vol.422 (1), p.719-730
• Main Authors: Rembold, S. B., Pastoriza, M. G.
• Format: Article
• Language: English
• Subjects: galaxies: clusters: general; galaxies: clusters: individual: LCDCS‐S001; galaxies: high‐redshift; Kinematics; Parameter estimation; Stars & galaxies
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2012.20651.x

We present photometric parameters of the galaxies in the direction of the galaxy cluster LCDCS-S001 and improved kinematic parameters from new spectroscopic observations. From GMOS multi-object spectroscopy, we have been able to confirm a new set of 10 cluster members, resulting in a total 22 objects from previous observations. With these data, a dispersion velocity of σ= 887 ± 249 km s−1, a virial radius R 200= 0.98 ± 0.22 Mpc and a mass of M 200= (5.4 ± 2.8) × 1014 M⊙ have been derived. From GMOS i′ and r′ images, we have extracted the individual sources and derived their magnitudes, relative positions and the bulge+disc brightness profile decomposition. We show that the cluster has an elongated morphology along the north-south direction, with ellipticity ɛ= 0.49 ± 0.14, well represented by a King model with a core radius R C= 283 ± 66 kpc, above the typical core radii of regular clusters. It shows at least one local overdensity, north-west from the cluster centre, very compact and with a very high central density. The i′ luminosity function of LCDCS-S001 has an almost flat faint-end, α=−1.16 ± 0.18. As for the constituent galaxies, we have found that a large fraction of the cluster galaxies are late-type systems. Extensive simulations were made in order to verify the validity of our conclusions. We discuss the implication of these results for the evolutionary status of LCDCS-S001 and conclude that this cluster is still dynamically young.