Simulating the evolution of the cold interstellar medium in galaxies hosting bright quasars


Observations of the dynamics of stars and interstellar clouds in the nuclei of the Milky Way and neighbouring galaxies show that most galaxies contain a supermassive black hole at their centre with typical mass 10^6 - 10^10 times that of the Sun. The energy released during the growth of such supermassive black holes is more than a few hundred times higher than necessary to unbind their entire host galaxy, suggesting that black hole growth is able to profoundly influence galaxy evolution. The physical processes that are responsible for mediating the energy released by active galactic nuclei (AGN) to the interstellar medium (ISM), known as ‘AGN feedback’, however, remain largely unknown. The main gap in our understanding is the fate of the cold (T = 10^2 - 10^4 K) component of the ISM when exposed to AGN winds and ionising radiation. The cold ISM is where star formation occurs and it therefore plays a crucial role in determining a galaxy’s evolution. This key aspect of the problem has been overlooked due to (1) the absence of a treatment for the AGN radiation field and (2) incomplete modelling of the thermochemical processes that govern its evolution. In this project, we propose to combine two novel numerical tools: the fully radiation-hydrodynamic code RAMSES-RT (Rosdahl et al., 2013; Rosdahl & Teyssier, 2015) and a comprehensive model for non-equilibrium chemistry and cooling (Richings et al., 2014a&b) in order to explore for the first time the interaction between AGN radiation and the cold ISM in simulations of galaxy formation.


Project number


Main applicant

Dr. T.A. Fernandes Gomes da Costa

Affiliated with

Universiteit Leiden, Faculteit der Wiskunde en Natuurwetenschappen, Sterrewacht Leiden


04/10/2017 to 08/11/2017