Chris Harrison : De-mystifying galactic outflows driven by supermassive black holes

Speaker : Dr. Chris Harrison (Newcastle University)
Date : 24th June 2025
Title : De-mystifying galactic outflows driven by supermassive black holes
Abstract : Episodes of supermassive black hole growth are known as “active galactic nuclei” (AGN). These are crucial periods in the life cycle of all massive galaxies. One way in which AGN can influence galaxies, is by driving multi-phase outflows of gas. However, the orders-of-magnitude ranges in spatial, temporal, and temperature scales makes this a very challenging process to constrain observationally. Questions remain on the properties, potential impact, and physical drivers of these outflows. I will present our work exploring these questions by combining cosmological simulations, high-resolution simulations of individual galaxies, and multi-wavelength observations. The power of this combined approach is understanding how specific observational experiments can (or cannot) test specific aspects of different theoretical models. Indeed, I will show how some published observational evidence that is in apparent contradiction with models, can be explained away once accounting for missing/unknown information in the data, and with a clearer understanding of which measurements can be robustly compared to simulations. I will finish by presenting new observational results highlighting a connection between dust, radio emission, and AGN outflows that now requires a physical explanation.