Black holes (BHs) are extreme cosmic objects where gravity is so intense that it warps spacetime and challenges our understanding of physics. They are not just endpoints of stellar evolution but powerful engines that shape galaxies and influence the universe's evolution. At their core, BHs test the limits of general relativity (GR) and quantum mechanics, making them key to understanding fundamental physics.
Contrary to their popular image as passive voids, BHs are dynamic systems. They accrete matter, launch relativistic jets, and emit radiation across the electromagnetic spectrum. These processes affect their surroundings on scales billions of times larger than the BH itself. However, our understanding of these phenomena is limited by the range of scales involved—from stellar-mass BHs (SBHs) to supermassive BHs (SMBHs)—and by fragmented observations across different wavelengths and communities.
The Event Horizon Telescope (EHT) has provided the first direct images of BHs, revealing the shadow of M87* and soon Sgr A*. These images mark a milestone but are static and blurred by turbulent plasma. To truly understand BHs and test GR, we must move beyond snapshots to dynamic, multi-wavelength observations that capture the full complexity of BH environments.
The BlackHolistic project proposes a transformative approach: creating the first high-resolution, multi-color BH movies of BHs across all relevant scales. By integrating data from the EHT, the new Africa Millimetre Telescope (AMT), and other facilities like the Cherenkov Telescope Array (CTA), MeerKAT, and the Square Kilometre Array (SKA), we aim to bridge the gap between micro- and macro-scale BH phenomena. These observations will be interpreted using advanced simulations incorporating general relativistic magnetohydrodynamics (GRMHD) and particle acceleration physics.
Our overarching goal is to develop the first holistic paradigm of BH astrophysics, connecting the inner accretion flow near the event horizon to the outermost jet structures. This includes:
Imaging BH dynamics: Capturing time-resolved, multi-wavelength movies to study accretion and jet formation in real time.
Understanding particle acceleration: Identifying where and how high-energy flares and radiation originate.
Quantifying energy output: Measuring how BHs convert infalling matter into radiation, particles, and kinetic energy, and assessing the role of BH spin.
Unifying BH classes: Using scaling laws to transfer insights between SBHs and SMBHs.
Developing predictive models: Creating a publicly available “BH model atlas” linking observable properties to fundamental parameters like mass, spin, and magnetization.
The expected impact is substantial. Scientifically, we will improve tests of GR by an order of magnitude, clarify the origin of high-energy cosmic particles, and understand BHs’ role in galaxy evolution. Technologically, we will develop new observational infrastructure and high-performance computing tools. Strategically, the AMT will secure Europe’s leadership in global BH research.
By integrating data across the electromagnetic spectrum and mass scales, BlackHolistic will answer long-standing questions in astrophysics and lay the groundwork for future space-based interferometry missions. The project’s interdisciplinary nature—combining observational astronomy, theoretical physics, numerical modeling, and data science—ensures broad scientific relevance.
In summary, BlackHolistic transforms our approach from static imaging to dynamic, multi-scale, and multi-messenger exploration. It offers a comprehensive understanding of BHs and their cosmic influence, setting the stage for a new era in black hole research.
