Title: CALIMA: Opening the window to the imprint of formation and evolution of H2, CO, dust and PAHs on the ISM

Abstract:  The thermodynamical state of the interstellar medium (ISM) in the local Universe is now understood to arise from a tightly coupled network of processes. Much of this progress, however, has been driven by theoretical frameworks that remain incomplete in their ability to self-consistently predict the co-evolution of all these components. Modern galaxy formation simulations have reached a remarkable level of sophistication, yet they typically rely on simplified treatments of radiative processes and of the microphysical mechanisms governing ISM heating and cooling. Conversely, photo-chemical models such as CLOUDY provide a detailed description of interactions between radiation, ions, molecules, and dust, but lack the ability to capture the dynamical, multi-scale nature of the ISM. Understanding the processes regulating the formation and evolution of molecules, dust, and polycyclic aromatic hydrocarbons (PAHs) is therefore crucial for galaxy evolution across cosmic time. These mechanisms remain poorly constrained under the low-metallicity, high star formation rate conditions characteristic of the high-redshift Universe. To address this gap, I will present the first fully self-consistent model of dust, CO, and H₂ implemented within the RAMSES code. This framework is coupled to radiative transfer, non-equilibrium thermochemistry, and a realistic multi-phase ISM description, and explicitly tracks carbonaceous and silicate grains together with PAHs. I will highlight applications ranging from high-resolution simulations of isolated galaxies probing the link between dust and PAH properties and local ISM conditions, to cosmological simulations exploring the origin and evolution of dust in the first galaxies.

Where? ENS Monod, Amphi C