Sweeping galaxies clean: how do black holes drive powerful molecular outflows? (astronomy)

In order to reproduce the tight correlations observed between galaxies and the supermassive black holes that lie in their hearts, galaxy formation and evolution models require accretion powered active galactic nuclei (AGN) to drive large outflows and quench galaxies. In order to shut down star formation on short timescales these outflows must strongly affect the cold gas: destroying it, or driving it out of the galaxy entirely. Recently a series of observational studies have shown that AGN can drive cold gas from galaxies, however these studies leave a large number of open questions. This project aims to address these questions, using (magneto-)hydrodynamic simulations with molecular chemistry to predict the properties of cold gas in outflows, and how these properties change with e.g. differing ejection
mechanisms and gas conditions. Initially the student will explore simple molecular chemistry in the outflow, focusing on H2 and CO. The chemical networks for these species are already implemented in our version of the Arepo astrophysical fluid code. She/he will then have the opportunity to look at more complex species using a ’tracer particle’ method. The student can then compare these simulations with existing and new observational data (from world leading facilities such as the Atacama Large Millimetre/submillimetre Array) to shed light on these complex processes that shape the evolution of galaxies. The student who takes on this project will pick up a wide range of research skills, including numerical modelling (fluids codes/radiative transfer/chemical modelling) and observational techniques.