Galaxy evolution across cosmic time

Massive galaxies provide a unique laboratory to investigate physical mechanisms driving galaxy evolution. While the initial condition for their formation is provided by their cosmological environment, observations have revealed that galaxies have acquired diverse structures, colours and kinematics already in the first few billion years after the Big Bang. Galaxy evolution is thus driven by a myriad of processes on different scales, such as gravity, heating and cooling, feedback, and phase transition. While our characterization of distant galaxies has improved in recent years with observations using the Hubble Space Telescope and the Atacama Large Millimeter Array, fundamental questions remain. What processes regulate star formation in galaxies? What is the role of supermassive blackholes in shaping their host galaxies? I will discuss how these questions are best tackled with a multi-wavelength approach, enabling a comprehensive census of gas and stars in galaxies. The research area of galaxy evolution is entering a transformative era with the launch of the James Webb Space Telescope in 2021, as it will detect the first galaxies and provide unprecedented details on galaxies at their peak of formation. Canada is well-positioned to make great strides in this field given its access to the most powerful telescopes and the construction of the Gemini Infrared Multi-Object Spectrograph, the first instrument of its kind that provides sharp, 3D views of distant galaxies. I will describe a vision for harnessing these facilities to answer the most pressing questions in galaxy formation and evolution.