KNOBEL , C.

We present a group-galaxy cross-correlation analysis using a group catalog produced from the 16,500 spectra from the optical zCOSMOS galaxy survey. Our aim is to perform a consistency test in the redshift range 0.2 \textless= z \textless= 0.8 between the clustering strength of the groups and mass estimates that are based on the richness of the...

We identify 42 "candidate groups" lying between 1.8\textlessz\textless3.0 from a sample of 3502 galaxies with spectroscopic redshifts in the zCOSMOS-deep redshift survey within this same redshift interval. These systems contain three to five spectroscopic galaxies that lie within 500 kpc in projected distance (in physical space) and within 700...

International audience

International audience

Our goal is to develop a new and reliable statistical method to classify galaxies from large surveys. We probe the reliability of the method by comparing it with a three-dimensional classification cube, using the same set of spectral, photometric and morphological parameters.We applied two different methods of classification to a sample of...

We use the overdensity field reconstructed in the volume of the COSMOS area to study the nonlinear biasing of the zCOSMOS galaxies. The galaxy overdensity field is reconstructed using the current sample of ~8500 accurate zCOSMOS redshifts at I(AB)<22.5 out to z~1 on scales R from 8 to 12 Mpc/h. By comparing the probability distribution function...

We present new improved constraints on the Hubble parameter H(z) in the redshift range 0.15 \textless z \textless 1.1, obtained from the differential spectroscopic evolution of early-type galaxies as a function of redshift. We extract a large sample of early-type galaxies ( 11000) from several spectroscopic surveys, spanning almost 8 billion...