Low X-ray Luminosity Galaxy Clusters. III: Weak Lensing Mass Determination at 0.18 << z << 0.70

This is the third of a series of papers of low X-ray luminosity galaxy clusters. In this work we present the weak lensing analysis of eight clusters, based on observations obtained with the Gemini Multi-Object Spectrograph in the $g'$, $r'$ and $i'$ passbands. For this purpose, we have developed a pipeline for the lensing analysis of ground-based images and we have performed tests applied to simulated data. We have determined the masses of seven galaxy clusters, six of them measured for the first time. For the four clusters with availably spectroscopic data, we find a general agreement between the velocity dispersions obtained via weak lensing assuming a Singular Isothermal Sphere profile, and those obtained from the redshift distribution of member galaxies. The correlation between our weak lensing mass determinations and the X-ray luminosities are suitably fitted by other observations of the $M-L_{X}$ relation and models

Weak lensing measurement of the mass-richness relation using the SDSS database

We study the mass-richness relation using galaxy catalogues and images from the Sloan Digital Sky Survey. We use two independent methods: In the first one, we calibrate the scaling relation with weak-lensing mass estimates. In the second procedure, we apply a background subtraction technique to derive the probability distribution, P(M|N), that groups with N-members have a virialized halo mass M. Lensing masses are derived in different richness bins for two galaxy systems sets: the maxBCG catalogue and a catalogue based on a group finder algorithm developed by Yang et al. Results of maxBCG are used to test the lensing methodology. The lensing mass?richness relation for the Yang et al. group sample shows a good agreement with P(M|N) obtained independently with a straightforward procedure.Fil: Gonzalez, Elizabeth Johana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Rodriguez, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Garcia Lambas, Diego Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Merchan, Manuel Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Foëx, Gael. Max Planck Institute for Extraterrestrial Physics; AlemaniaFil: Chalela Garcia, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentin

Dynamical analysis of strong-lensing galaxy groups at intermediate redshift

20 pages, 5 figures in body, 7 figures in appendix, accepted by Astronomy and AstrophysicsInternational audienceWe present VLT spectroscopic observations of 7 discovered galaxy groups between 0:3 < z < 0:7. The groups were selected from the Strong Lensing Legacy Survey (SL2S), a survey that consists in a systematic search for strong lensing systems in the Canada- France-Hawaii Telescope Legacy Survey (CFHTLS). We give details about the target selection, spectroscopic observations and data reduction for the first release of confirmed SL2S groups. The dynamical analysis of the systems reveals that they are gravitationally bound structures, with at least 4 confirmed members and velocity dispersions between 300 and 800 km s1. Their virial masses are between 1013 and 1014 M , and so can be classified as groups or low mass clusters. Most of the systems are isolated groups, except two of them that show evidence of an ongoing merger of two sub-structures. We find a good agreement between the velocity dispersions estimated from the analysis of the kinematics of group galaxies and the weak lensing measurements, and conclude that the dynamics of baryonic matter is a good tracer of the total mass content in galaxy groups

Dissecting the Strong-lensing Galaxy Cluster MS 0440.5+0204. II. New Optical Spectroscopic Observations in a Wider Area and Cluster Dynamical State

International audienceWe present an optical study of the strong-lensing galaxy cluster MS 0440.5+0204 at z = 0.19593, based on CFHT/MegaCam g′, r′ photometry and GMOS/Gemini and CFHT/MOS/SIS spectroscopy in a broader area than previous works. We have determined new spectroscopic redshifts for the most prominent gravitational arcs surrounding the central galaxy in the cluster. The new redshifts and the information provided by the photometric catalog allow us to perform a detailed weak- and strong-lensing mass reconstruction of the cluster. The large number of member galaxies and the area covered by our observations allow us to estimate more accurately the velocity dispersion and mass of the cluster and to examine in detail the nature of the cluster and surrounding structures. The dynamical mass is in good agreement with the mass inferred from the lensing analysis and X-ray estimates. About 68% of the galaxies are located in the inner ≲0.86 Mpc region of the cluster. The galaxy redshift distribution in the inner region of the cluster shows a complex structure with at least three substructures along the line of sight. Other substructures are also identified in the galaxy density map and in the weak-lensing mass map. The member galaxies in the northeast overdensity are distributed in a filament between the clusters MS 0440.5+0204 and ZwCL 0441.1+0211, suggesting that these two structures might be connected. MS 0440.5+0204 appears to be dynamically active, with a cluster core that is likely experiencing a merging process, and with other nearby groups at projected distances of ≲1 Mpc that could be being accreted by the cluster

Weak lensing analysis of the galaxy clusterRX J1117.4+0743 ([VMF 98] 097)

We present a weak lensing analysis of the galaxy clusterRX J1117.4+0743 ([VMF 98] 097) at z=0.485, based on data collectedwith Gemini South Telescope. The cluster was formerly analyzed byCarrasco et al. (2007, ApJ, 664, 777), and they found a large discrep-ancy between the mass estimated from Xray observations and lensingestimates, exceeding the X-ray mass by more than a factor three. Ourresult for the mass from the weak lensing analysis is lower than the massobtained by Carrasco et al. and closer to the X-ray mass.Presentamos el analisis de lente debil del cumulo de galaxias RX J1117.4+0743 ([VMF 98] 097) situado enz= 0.485, utilizando observaciones obtendias por el Telescopio Gemini Sur. El cumulo fue anteriormente analizado por Carrasco et al. (2007, ApJ, 664, 777), quienes encontraron una gran discrepancia entre la masa estimada a partir de observaciones en rayos X y la obtenida a partir del analisis de lente debil,siendo la masa de lentes mas de tres veces mayor. La masa que obtuvimos a partir del analisis de lente debil es menor que la obtenida por Carrasco et al. y mas cercana a la masa obtenida en X.Fil: Gonzalez, Elizabeth Johana. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomia Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomia Teórica y Experimental; ArgentinaFil: Dominguez Romero, Mariano Javier de Leon. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomia Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomia Teórica y Experimental; Argentina. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Garcia Lambas, Diego Rodolfo. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomia Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomia Teórica y Experimental; ArgentinaFil: Moreschi, Osvaldo Mario. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Foëx, Gael. Pontificia Universidad Católica de Valparaíso; ChileFil: Nilo Castellon, Jose Luis Emilio. Universidad de la Serena; ChileFil: Alonso, Maria Victoria. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomia Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomia Teórica y Experimental; Argentin