Do AGN winds teach galaxies to breathe and grow?
In the heart of most galaxies sits a supermassive black hole, quietly feasting on gas until it erupts in an outflow that can sweep across thousands of light-years. For decades, astronomers have wrestled with a simple question: when these winds surge outward, do they snuff out star formation or do they set the conditions for galaxies to evolve in surprising ways? A new study, led by Cosimo Marconcini and Alessandro Marconi, teams up Italian and international researchers from Università degli Studi di Firenze and INAF’s Arcetri Observatory, along with collaborators across Trento, Pisa, and beyond, to offer a detailed, three-dimensional view of these winds as they travel from the nuclear region into the galactic suburbs. The result is not just a better map of gas; it’s a sharper probe of how black holes and their hosts grow together, sometimes in a push-pull dance rather than a simple tug-of-war.
What makes this work stand out is a new way of looking at the gas clouds that make up the winds. The team uses MOKA3D, a three-dimensional kinematic model designed to handle the clumpy, messy reality of gas in galaxies. Instead of forcing the data into smooth, idealized shells, MOKA3D treats the outflow as a swarm of clouds moving outward in a conical geometry, while a rotating disk of gas ripples beneath. That approach lets the researchers recover the true, intrinsic motions of the wind, free from the distortions of how we happen to view the galaxy from Earth. The study builds on the MAGNUM survey and observations with the MUSE instrument on the Very Large Telescope, stretching from the nucleus out to several kiloparsecs. And the authors don’t stop at “how fast?” They ask, “how does the wind evolve as it travels, and what does that mean for the fate of the host galaxy?”
A new lens on winds Earthside: MOKA3D and the clumpy ISM
The wind physics at play around active galactic nuclei is a long-running mix of elegant theory and messy reality. Theory has long predicted that a fast, nuclear wind first charges outward, then slows and transfers its energy to the surrounding gas in a way that changes its cooling. Depending on how efficiently the shocked gas can radiate away energy, the wind can be momentum-driven—like a push that keeps a constant speed—or energy-driven, where thermal pressure accelerates the swept-up gas to higher speeds. The difference matters a lot: in an energy-driven regime, the wind has more oomph to sweep gas out of the galaxy and suppress future star formation.
Marconcini and colleagues deploy MOKA3D to tackle a chronic challenge in this field: the interstellar medium (ISM) in galaxies is clumpy, irregular, and full of structure. Traditional models often assume a smooth gas distribution, which can blur the real kinematics and produce biased inferences about how much gas is being ejected and how fast it’s moving. MOKA3D, instead, builds a 3D representation of many clouds arranged in a bi-conical outflow, sliced into shells. For each shell, two parameters—outflow velocity and inclination relative to our line of sight—are fit so that the model reproduces the observed line profiles and velocity maps. In practice, that means we can peel back projection effects and see the wind’s intrinsic speed as a function of distance from the black hole.
One of the paper’s strongest demonstrations comes from NGC 1365, a nearby Seyfert II galaxy. The authors’ model reconstructs an outflow that is not simply fast near the core and then slow outward; instead, the wind starts with high speeds close to the center and accelerates with distance, a trend that emerges clearly once you account for the clumpy gas and the galaxy’s own rotation. They divide the outflow into eight concentric shells, tracing how the intrinsic velocity climbs from roughly 900 km/s near the nucleus to about 1500 km/s a few kiloparsecs out. The result is striking: even when the observed emission looks chaotic, the intrinsic velocity field behaves like a smooth, radially driven wind once you correct for geometry and clumpiness.
The accelerating wind and the shock physics
Across the MAGNUM sample, the same pattern keeps showing up. The outflows rise with distance from the black hole in a fairly uniform way: for the first ~1 kiloparsec, the velocity is roughly constant or only slowly declining; beyond that, the gas undergoes rapid acceleration, roughly doubling its radial speed over the next few kiloparsecs. The researchers emphasize that this acceleration is not a quirky feature of any single galaxy but a shared trait among ten nearby active galaxies. The scale—about 1 kpc—maps neatly onto the theoretical boundary between momentum-driven and energy-driven winds described in earlier models. At smaller radii, Compton cooling is efficient; the post-shock gas loses energy quickly and the wind remains momentum-driven. Once the wind travels beyond roughly 1 kpc, cooling becomes inefficient, the thermal pressure of the shocked gas builds up, and the system becomes energy-driven, accelerating the shells outward.
To connect the dots, the team also decouples the outflow from the rotating galactic disk. By fitting the disk and outflow simultaneously, they extract the true velocity needed for gas to escape the host galaxy’s gravitational pull. In several galaxies, the measured outflow speeds exceed the local escape velocity by factors of up to four, which means the wind is not just stirring the ISM; it can remove gas from the galaxy altogether, potentially shutting down future star formation and choking the black hole’s fuel supply in a self-regulating loop.
In their analysis, the authors situate their observations within a broader theoretical framework that links black hole growth with the bulge of the host galaxy—the famous M-σ relation. The 1 kpc threshold aligns with the idea that a sufficiently powerful, energy-driven wind can push gas out beyond the galaxy’s effective radius, effectively “clearing” the central regions and limiting further accretion. The team’s escape-velocity calculations, derived from two independent mass models, reinforce a consistent story: many winds move fast enough to escape the disk’s grip, carrying gas into the halo and potentially into intergalactic space.
What this means for galaxies and the cosmos
There’s a practical takeaway woven through all of this: to truly understand AGN feedback, we need to measure intrinsic gas velocities and how they evolve with radius, not just the plumes of light we see projected on the sky. The study makes a strong case that high-resolution, three-dimensional modeling is essential to reveal the energy that winds deposit into their surroundings. If we underestimate the wind’s speed because we neglect projection effects or ignore the clumpy nature of the ISM, we risk underestimating the wind’s kinetic power and its ability to alter a galaxy’s fate. The authors are explicit about this caveat, and their work underscores why future observations—especially at higher redshift where the most vigorous quasar-era feedback is thought to have happened—will require both better spatial detail and more sophisticated modeling.
Beyond the technical achievement, the results matter for the bigger questions about galaxy evolution. AGN winds have long been proposed as a mechanism that can clear gas, quench star formation, and keep black holes from overgrowing relative to their hosts. The finding that acceleration occurs beyond ~1 kpc and that the fastest shells reach or exceed escape velocity provides a plausible, physically grounded path for winds to sculpt the structure and content of galaxies on multi-kiloparsec scales. It also helps explain why some galaxies in the local universe look as if they’ve suffered dramatic, galaxy-wide feedback while their central engines stayed active—the energy from the AGN reaches far beyond the nucleus, shaping the surrounding ISM and, in some cases, the halo.
Another layer of significance is methodological. The study demonstrates that 3D kinematic modeling, when combined with high-quality IFU data, can turn what used to be a mass- and geometry-laden guessing game into a principled reconstruction of how winds move through real, messy galaxies. In this sense, MOKA3D is more than a tool; it’s a new lens through which to view feedback processes in action. By capturing the clumpy ISM and by deprojecting the outflow geometry shell by shell, the researchers show that the observed complexity is not a signature of chaotic winds but a reflection of a relatively orderly radial flow wrapped in a patchwork of clouds.
From local laboratories to cosmic history
When we zoom out, the implications reach toward the cosmic story of galaxy formation. At the peak of galaxy assembly, around redshifts z ~ 1–3, AGN-driven winds are thought to play a central role in regulating star formation and shaping the metal enrichment of galaxies. The new results give us a more concrete picture of how energy is transferred from the AGN into the host, and how that energy can drive gas to the outer regions or even beyond the galaxy. They also highlight a practical risk for high-redshift studies: if we’re not resolving the energy-driven phase or if we’re missing the faint, extended emission that accompanies it, we may systematically underestimate the wind’s power and its potential to impact the galaxy’s life cycle. The authors call for more robust measurements of ejected mass rates and for larger samples that can reveal how common these accelerating winds are across different galaxy types and cosmic epochs.
The collaboration behind the work is a tapestry of institutions: Università degli Studi di Firenze and INAF – Osservatorio Astrofisico di Arcetri in Italy anchor the core efforts, with partners at the University of Trento, Scuola Normale Superiore, and international allies at Max Planck Institute for Extraterrestrial Physics, University of Leicester, University of Amsterdam, and Leiden University. The lead author, Cosimo Marconcini, together with Alessandro Marconi, also emphasize that this is a team achievement—one that leverages the sophistication of MOKA3D and the depth of the MAGNUM survey to push forward our understanding of AGN feedback in the local universe and beyond.
Looking ahead, the researchers plan to apply MOKA3D to more galaxies across a range of distances, building a statistics-driven view of how common the acceleration regime is and how it depends on the properties of the black hole and its host. If the pattern holds across a broader sample, it would strengthen the case that AGN winds are not episodic disruptors but steady shapers of galactic ecosystems, capable of driving gas out to the halo and beyond, while letting new stars still form in reservoirs that resist the wind’s reach. In other words, the wind doesn’t just clear a path for the black hole; it helps the galaxy breathe, adapt, and grow in a universe where gas is the currency of both life and light.
In a sense, we’re watching the universe’s most powerful engines negotiate a delicate balance: black holes grow by feeding, galaxies grow by forming stars, and the winds that connect them choreograph a dance that can tilt a galaxy toward quiet quietude or toward renewed vigor. The new study gives us a more faithful map of that dance—and a sharper sense of just how far the music can carry.
