Séminaire Doctoral / Seminar PhD |
| « Clusters of galaxies in the cosmic web : influence of environment on galaxy evolution » |
|
Florian Sarron |
|
Observations using spectroscopic redshifts have been showing for several decades that galaxies are not evenly distributed in the sky but rather along filaments and sheets, at the intersection of which lie galaxy clusters. Such large scale structures (LSS) for the repartition of matter in the universe has also been seen in numerical simulations, where clusters of galaxies lie at the intersection of several filaments and are accreting galaxies and groups of galaxies along these preferred directions throughout cosmic time.
However, large sample of galaxy clusters up to medium-high redshift and study of galaxy populations within them have been rare so far. In this talk, I will present a method based on kernel density estimation to detect galaxy clusters using photometric redshifts (photo-z) up to z ~ 1.1. Using this method on the Canada France Hawaii Telescope Legacy Survey (CFHTLS) - a survey covering more than 170 deg2 - we detected more than 3000 candidate clusters. I will present very preliminary results on the influence of environment on galaxy evolution obtained from the study of this sample. I will then outline the challenge that is detecting filaments of galaxies with using such photo-z. |
|
mercredi 8 février 2017 - 17:00 Salle Entresol Daniel Chalonge, Institut d'Astrophysique |
| Page web du séminaire / Seminar's webpage |