Years of astrophysical studies have placed interactions between galaxies and the circumgalactic medium at the centre of our quest to understand galaxy evolution. However, determining what drives the physical processes at play in the circum-galactic medium still remains a complex problem in galaxy formation, in large part due to the lack of significant observational constraints. This ISSI International Team initiative proposes to transform our understanding of the multi-phase circum-galactic medium gas of intermediate redshift galaxies (z~1). The team we are putting together includes more than 10 researchers from three different continents with expertise ranging from instrument building and telescopes operation, spacebased data advanced processing and analysis, observations ranging from mm to optical domains as well as advanced cosmological simulations. An important component of the project relies on over 130 orbits of observations with the Hubble Space Telescope secured by our team. The project combines a statistical approach in absorption with dedicated emission observations of remarkable targets. The main goal of the survey is to reveal and understand the physical processes responsible for the rapid transformation of baryons in and out of galaxies to address the following important questions:
- What is the physical relation between galaxies and their gaseous haloes?
- How is the circum-galactic medium enriched with metals?
- What is the dynamical structure of gas flows in the circum-galactic medium?
- Which future observational programs and space-based facility development should we aim for?