Presentation 
The visible universe is highly inhomogeneous at small scales, being the luminous matter condensed in stars, which are grouped forming galaxies. The galaxies can evolve in isolation, forming the so called field population, or they can be gravitationally bounded with other galaxies forming galaxy associations which goes from small groups up to massive galaxy clusters or superclusters. These are the biggest virialized structures known in the Universe. During decades, galaxy clusters have been used in order to determine large-scale properties of the Universe, and confirm or refuse cosmological theories. They have also been used in order to understand the evolutive processes of galaxies. While field galaxies evolved passively, galaxies in clusters evolved depending on the environment. One of the challenges of modern Astrophysics is to obtain a good theory about galaxy evolution, and one of the keys of this theory will be to explain the role placed by the environment in this evolution.
It has been known since the earliest observations of rich clusters that the properties of galaxies in clusters are quite distinct from field galaxies. The cluster population is dominated by early-type morphologies, primary ellipticals and S0s. They are the most abundant and homogeneous family of galaxies in clusters, following tight relations as: fundamental plane or the color-magnitude relation, and dominate the cores of the clusters and should been in place before cluster virialization. They have an old stellar population, which indicates that the population of Elliptical galaxies in clusters are evolving passively from high redshift. In contrast, late-type galaxies in clusters are less abundant than in field and are located in the outermost regions where the local density is not very high. This distribution of the morphologies in clusters is called the morphology-density or morphology-clustercentric radius relations.
The differences between galaxies in field and clusters suggested that galaxies in clusters may have an intrinsically different formation process to field galaxies. However, since the general acceptance of the hierarchical process as the preferred model of structure formation, in which bright galaxies would be the result of successive mergers and interactions, much attention has been focused on mechanisms that could transform late-type star forming galaxies in dense environments. Actually, the most accepted theoretical framework about cluster evolution claims that galaxies are continuously falling into the cluster potential, and stars and gas are striped from them due to fast encounters between galaxies and with the cluster gravitational potential. This is the so-called harassment scenario. This process can be active until the present epoch and gives a number of observational properties in the galaxies that can be tested. In particular, the harassment scenario proposes that: discs of galaxies in clusters should be different than in field due to the stop of the star formation and the striped of stars; dwarf galaxies would be not primordial objects being modified bright late-type galaxies due to close interactions between galaxies or with the cluster gravitational potential. The striped stars from galaxies should be located in the intracluster region, free flying in the cluster potential, forming the so-called diffuse light. This cluster component should be nonrelaxed, and more important in clusters with more harassed galaxies. The goal of the present project is to measure those observational predictions of the harassed theory for a sample of nearby galaxy clusters with different physical properties. This will be done by studying: the quantitative morphology of galaxies in clusters, and the properties of the diffuse light.
This research project will provide strong observational constrains to theories about galaxy evolution in galaxy clusters. This project will also be an important milestone for future works about galaxy clusters at higher redshift.