London – Black holes at the center of galaxies are not just matter-consuming giants; they are cosmic architects. This is the conclusion of an international research team led by the University of Florence and INAF – Arcetri Astrophysical Observatory, whose work has been published in Nature Astronomy. The study has, for the first time, demonstrated that winds generated by black holes experience a sudden acceleration as they move away from the galactic center, playing a crucial role in the evolution of galaxies.

"Every galaxy hosts a supermassive black hole at its core," explain the study’s lead authors, Cosimo Marconcini and Alessandro Marconi, respectively a PhD student and a professor of astrophysics at the Department of Physics and Astronomy of the University of Florence. "These active galactic nuclei (AGN) consume matter while generating powerful gas winds that spread into the surrounding space."

The researchers made a surprising discovery: within the first 3,000 light-years (1 kiloparsec) from the source, the winds either move at a constant speed or even slow down slightly; but after that, they undergo a dramatic expansion, heat up, and accelerate, reaching speeds capable of expelling all the gas they encounter from the galaxy.

This discovery was made by analyzing the winds of 10 galaxies observed using the Very Large Telescope (VLT) of the European Southern Observatory in Chile—the world's most important astronomical facility—and with a new 3D data modeling tool called MOKA3D, developed by the research team.

Why is this discovery so important? Because supermassive black holes can drive gas out of galaxies, halting star formation and influencing their evolution. "In fact," the researchers explain, "AGN winds regulate star formation: if the wind sweeps away too much gas, the galaxy will have less 'fuel' to form new stars. They can influence the distribution of gas and chemical elements and even halt the galaxy's growth: if the wind is strong enough to eject gas into intergalactic space, the galaxy itself may stop expanding."

The next frontier is to study other galaxies, including those at great distances, to determine whether this phenomenon is common across the universe, further establishing black holes as key shapers of their host galaxies. (9colonne)