Evolution des propriétés physiques des galaxies centrales les plus brillantes des amas de galaxies

Galaxy clusters are the largest gravitationally bound structures of the Universe. At the center of these clusters generally reside the most massive galaxies observable today. These galaxies are refered to as Brightest Cluster Galaxies (BCGs), and are the final products of 10 Gyrs of consecutive galactic mergers in the densest regions of the cosmic web. In this thesis, we focus our attention on these very peculiar objects, excellent tracers of cluster formation, and ideal to study the impact of environmental processes on galactic formation. The characterization of the physical properties of BCGs is important to obtain better knowledge of these galaxies. Previous studies have found contradicting results concerning their growth: while some studies find that they are still evolving today, others find that they may have stopped growing a long time ago. In order to put things in perspective, I present here new catalogues of BCGs which have allowed me to conduct a deeper analysis of the formation of BCGs, thanks to the bigger statistics we reached. My work on the characterization of the physical properties of BCGs has shown a lack of evo- lution of their sizes and luminosities in the last 10 Gyrs, hinting at an earlier formation epoch and absence of recent significant growth. However, their structures may have changed over time, as hinted by the observation of a second component at recent epoch. This may only be due to observational biases, but deeper surveys such as the ones expected from the Euclid or the Ru- bin Observatory’s Legacy Survey of Space and Time (LSST) missions should enable us to confirm this. BCGs, because of their central locations, are more likely to undergo mergers in their lifetimes, which leave marks on their shapes. As a result, we confirm the special bond between BCGs and their host clusters as inferred from their alignments. I also offer new tools for automatic detections of BCGs on optical images. These may be ap- plied to large surveys with the u