Speaker
Description
Accreting black holes span a wide range of physical regimes across the full mass scale, from stellar-mass X-ray binaries to supermassive active galactic nuclei. Different theoretical approaches are often used to describe each regime. Within the ERC-funded project BlackHollisitic, our long-term goal is to bridge these approaches to create unified models that describe black hole accretion across different physical states.
One of the main empirical motivations for such unification is the fundamental plane of black hole activity (Merloni et al. 2003; Falcke et al. 2004) — an observed correlation between radio and X-ray luminosities in sub-Eddington accreting black hole systems. This relation suggests that similar physical processes govern both X-ray binaries (XRBs) in the low/hard state and radio-loud active galactic nuclei (AGN).
To investigate this, we employ General Relativistic Magneto-Hydrodynamical (GRMHD) simulations, which are widely used to interpret Event Horizon Telescope (EHT) observations of radio-loud AGN. Because these radiatively inefficient models are computed in a scale-free manner, they offer an ideal framework to test whether the same physical principles can reproduce the observed scaling relations that link XRBs and AGN along the fundamental plane.
In this study, we use the General Relativistic Radiative Transfer (GRRT) code RAPTOR (Bronzwaer et al. 2020) to compute synthetic radio and X-ray luminosities from GRMHD simulations and derive the corresponding correlation coefficients of the fundamental plane. These results are then compared with observational data to assess the universality of accretion physics across black hole mass scales.