Céline Gouin
Institut d'Astrophysique de Paris (Paris, France)
Galaxy clusters sit at the nodes of the cosmic web, linked by filaments that funnel matter from the surrounding universe. These structures are key to unlocking the secrets of galaxy evolution, gas accretion, and the growth of cosmic structures.
After outlining the central issues surrounding clusters and their connected filaments—such as cluster tension and the missing baryons problem—I will first show that the local connectivity of clusters is not only related to their mass but also traces their dynamical state and mass assembly history.
Next, I will demonstrate how anisotropic accretion shapes the gas flowing from filaments into clusters. While hot plasma is virialized inside clusters, the warm–hot intergalactic medium (WHIM) accumulates and slowly infalls at cluster peripheries. At the bridge between warm filaments and the intracluster medium, the gas emits soft X-rays, as revealed by simulations and recent observations.
Finally, the connection between clusters and the cosmic web also impacts galaxy properties, including star formation activity and morphology. Using Euclid Q1 data, I show that the cosmic web doesn’t just feed clusters—it also shapes the morphology of their galaxy members.
Clusters are thus natural laboratories, offering an unprecedented window onto the formation of large-scale structures and their impact on baryons, both gas and galaxies. With Euclid’s upcoming data, mapping filaments and clusters with unprecedented precision, along with eROSITA, XRISM, and NewAthena, we are poised to make major strides in understanding how the large-scale structure drives cluster evolution and baryonic properties.
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris