On a "small" scale (up to hundreds of millions of light years) the Universe is far from homogeneous. Galaxies are distributed on long sheets and filaments, and avoid the large and empty cosmic voids. At the crossing between filaments we find the most massive structures in the Universe: galaxy clusters, each hosting thousands of galaxies inside a small volume. To this day, clusters continue to pull more and more galaxies towards them thanks to their gravitational attraction. Galaxies falling into clusters undergo rapid evolution as they collide with one another and feel the pressure of the hot (up to hundreds of millions of degrees) ambient gas. Eventually, these interactions deprive galaxies of their own cold gas (from which new stars would form) and thus shut down their star formation. From that point on these galaxies evolves "passively", that is, they continue to age without forming new stars.
This ERC project, called FORNAX, investigates the exact physical mechanisms that determine the evolution of galaxies in clusters. In particular, as clusters come in different size and mass, we want to understand down to what cluster mass events such as galaxy collision and interaction with the cluster hot ambient gas are relevant. To do so we will study the nearest small cluster, called Fornax. We will do so using a brand new radio telescope, MeerKAT, located in South Africa. This telescope will allow us to observe the cold gas of galaxies in Fornax with unprecedented sensitivity and resolution, and answer the questions of whether, through what processes and how quickly this gas is being removed from them.
