Periodic Reporting for period 3 - KETJU (Post-Newtonian modelling of the dynamics of supermassive black holes in galactic-scale hydrodynamical simulations (KETJU))
Reporting period: 2022-07-01 to 2023-12-31
Understanding the formation and impact of supermassive black holes on the evolution of galaxies is a key open question in astrophysical research. Black holes are the most extreme gravitationally bound objects in the Universe, and as such very good testbeds for gravitational physics in extreme conditions. Thus, understanding better the impact of black holes also on galactic scales could potentially lead to new insights in our fundamental understanding of physics and the Universe in which we live.
The overall objective of this project is to simulate at unprecedented accuracy the dynamical evolution of supermassive black holes and their surrounding stars in galaxies that are formed in a full cosmological setting. In doing so we will be able to produce very high precision predictions of the gravitational wave signal from merging supermassive black holes in gas-rich galaxies. This will important when making predictions for future space-borne gravitational wave observatories, such as the European Space Agency’s LISA mission, which is planned to be launched in the mid-2030s.
Using the KETJU code we will study the formation of cores in cosmologically forming massive galaxies for the first time, as we are able to now resolve both the gaseous component and the strong gravitational interactions between the supermassive black hole binary and the surrounding stars. We will also simulate a large cosmological volume that resolves the formation of thousands of galaxies, and now for the first time also includes detailed dynamical modelling of their supermassive black holes. This will enable us to produce predictions of the expected gravitational wave background at unprecedented fidelity. Finally, we will study the formation of massive stellar clusters in merging gas-rich galaxies and using KETJU resolve for the first time also their internal dynamics in a gas-rich environment.
This project is thus expected to produce several landmark results in dynamical and gravitational astrophysics, especially related to the dynamics of supermassive black holes, the emission of gravitational waves and the formation and evolution of massive stellar clusters.