Abstract:
Massive black holes (MBHs) are found in the centres of most massive galaxies. When two galaxies merge, their respective MBHs are brought together, some of them will eventually coalesce and become powerful sources of gravitational waves (GWs). The detection of GWs from stellar-mass black hole binaries by the Laser Interferometer Gravitational-Wave Observatory (LIGO) marked the dawn of the GW astronomy era. Within the next 10-15 years, the Laser Interferometer Space Antenna (LISA) is expected to detect GWs from MBHB mergers with masses in the range of 10^4-10^7 solar masses out to high redshifts. In order to make predictions of the merger rate of LISA MBHs as well as interpreting the upcoming LISA data, we need to build a solid theoretical framework for the evolution of MBHBs to understand their dynamical behaviour and GW signatures. I will talk about the newest progress on MBH dynamics modelling and give a brief review on what else we have learnt from simulations about LISA MBHs, including the formation of MBH seeds, their growth channels, and their mergers, which will be very important for LISA. In this talk, I will particularly focus on our new model: RAMCOAL, which tracks on-the-fly MBHB evolution and coalescence in galaxy simulations. With RAMCOAL, we can better estimate MBHB coalescence rates and the GW background, while providing insights into the electromagnetic counterparts of GW sources. This approach bridges the gap between electromagnetic observations and GW detection, offering a more comprehensive understanding of MBHB evolution in cosmological simulations.
