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« Cluster galaxy luminosity functions in the CFHTLS »

Florian Sarron
Institut d'Astrophysique de Paris (Paris, France)

Obtaining large samples of galaxy clusters is important for cosmology, since cluster counts as a function of redshift and mass can constrain the parameters of our Universe. They are also useful to understand the formation and evolution of clusters.

We develop an improved version of the AMACFI cluster finder (now AMASCFI) and apply it to the 154 deg2 of the Canada France Hawaii Telescope Legacy Survey (CFHTLS) to obtain a large catalogue of 1371 cluster candidates with redshift z < 0.7 and mass greater than 10^14 solar masses.

We study the evolution of these clusters with mass and redshift by computing the i-band galaxy luminosity functions (GLFs) for the early- (ETGs) and late-type galaxies (LTGs). This sample is 90\% pure and 70\% complete, and therefore our results are representative of a large fraction of the cluster population in these redshift and mass ranges.

Our large sample allows us to break the degeneracy between mass and redshift, finding that the redshift evolution is more pronounced in high-mass clusters, but that there is no significant dependence of the faint end of the GLF on mass for a given redshift.
This allow us to conclude about the main physical processes that seems to drive galaxy evolution in clusters.
mercredi 15 novembre 2017 - 17:00
Salle Entresol Daniel Chalonge, Institut d'Astrophysique
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