Using cutting-edge simulations, scientists at Goethe University Frankfurt revealed that not just magnetic fields, but a process called magnetic reconnection, helps extract energy from a spinning black hole to launch jets of matter stretching thousands of light-years. These immense cosmic beams, moving at nearly light speed, scatter energy and matter across galaxies, shaping their evolution.

From a “Nebula Without Stars” to a Giant Galaxy
For nearly 200 years, astronomers were uncertain about the true nature of the bright object in the constellation Virgo that Charles Messier recorded in 1784 as “87: Nebula without stars.” What appeared to be a fuzzy patch of light was later revealed to be an enormous galaxy. When a mysterious jet of light was spotted coming from its center in 1918, scientists had no idea what could be producing it.

At the core of this massive galaxy, now known as M87, lies the supermassive black hole M87*, containing about six and a half billion times the mass of the Sun. This black hole spins rapidly, and its rotation powers a stream of charged particles that shoots out at nearly the speed of light, stretching some 5,000 light-years into space. Similar jets are seen around other rotating black holes, helping to scatter energy and matter throughout the universe and shape the growth of galaxies.

Cracking the Code of Black Hole Power
A research team from Goethe University Frankfurt, led by Prof. Luciano Rezzolla, has developed a new computational tool called the Frankfurt particle-in-cell code for black hole spacetimes (FPIC). This simulation code precisely models how a spinning black hole transforms its rotational energy into a powerful jet. The researchers discovered that, in addition to the well-known Blandford–Znajek mechanism, long thought to explain how black holes extract rotational energy through magnetic fields, another key process also plays a role: magnetic reconnection. In this phenomenon, magnetic field lines snap and reconnect, converting magnetic energy into heat, radiation, and bursts of plasma.

Using the FPIC code, the team simulated the behavior of countless charged particles and extreme electromagnetic fields influenced by the intense gravity surrounding the black hole. Dr. Claudio Meringolo, the main developer of the code, explained, “Simulating such processes is crucial for understanding the complex dynamics of relativistic plasmas in curved spacetimes near compact objects, which are governed by the interplay of extreme gravitational and magnetic fields.”

Running these simulations required extraordinary computing resources, totaling millions of CPU hours on Frankfurt’s “Goethe” supercomputer and Stuttgart’s “Hawk.” Such immense processing power was needed to solve Maxwell’s equations and the equations of motion for electrons and positrons within the framework of Albert Einstein’s general theory of relativity.