In just a few hours, astronomers recorded one of the fastest and most dramatic wind outflows from the immediate vicinity of a supermassive black hole ever observed. Two leading space X-ray observatories, ESA's XMM-Newton and the Japanese-European-American XRISM, tracked a short-lived but extremely intense X-ray flash in the heart of the spiral galaxy NGC 3783 almost in real-time. As the flash faded, a gust of ionized gas emerged from the accretion disk around the black hole, rushing outward at speeds of about 60,000 km/s – approximately one-fifth the speed of light. Such "ultra-fast outflows" (UFOs) have rarely been observed in such a clear temporal sequence: flash → wind formation → fading of the flash with simultaneous strengthening of absorption traces in the spectrum.

What happened in NGC 3783?

NGC 3783 is an active spiral galaxy located about 130 million light-years away. At its core lies a supermassive black hole with an estimated mass of about 30 million Suns. As it feeds on surrounding gas and dust, it creates an active galactic nucleus (AGN) that shines across the entire electromagnetic spectrum – from radio waves to X-rays. At the moment when the accretion flow temporarily accelerates or magnetic fields in the disk suddenly reconfigure, a short but extremely energetic X-ray flash can erupt. This is precisely what was seen: the flash first shone, then began to fade, and in its wake, the formation of winds followed, which – almost "overnight" – reached relativistic speeds of about 0.2c.

Crucially, XMM-Newton and XRISM observed the object synchronously. XMM-Newton tracked the evolution of the flash with its Optical Monitor and spectroscopy using EPIC cameras, while XRISM's high-energy resolution spectrometer Resolve "dissected" the wind spectrum – measuring their structure, ionization, and speed. Thanks to such a combination, the team reliably linked a short-lived flash with the almost instantaneous formation of ultra-fast winds for the first time: the formation process took place within a single day, which is astonishingly fast for AGNs.

Magnetism as a trigger: "unwinding" of fields

The most accepted explanation lies in the magnetic fields of the accretion disk. In more stable conditions, the fields are entangled, and energy is transferred by friction and turbulence. But when a sudden reorganization occurs – a process analogous to magnetic reconnection in the solar corona – part of the field "snaps" and releases immense amounts of energy. This sudden energy transfer simultaneously boosts X-ray radiation and "pulls" ionized gas from the disk, accelerating it into winds. The geometry and spectroscopic signature of the wind in NGC 3783 point exactly to this: lines of highly ionized iron (Fe XXV, Fe XXVI) and other elements show shifts and widths corresponding to high speeds and increased turbulence immediately after the flash.

For this diagnosis, the energy resolution offered by XRISM's Resolve was key – a micro-calorimeter capable of distinguishing subtle shifts and broadenings of absorption lines. At lower energies, absorption features of silicon, sulfur, and argon were also recorded. The combination of line widths and their shifts reveals a multi-layered structure of outflow streams with different ionizations and turbulent velocities, while the fastest, broad component reaches a relativistic regime. XMM-Newton continuously monitored the drop in the X-flash and the appearance of absorption features, "connecting" the phenomena into a clear temporal whole.

Why a speed of about 0.2c is crucial

A speed of approximately 60,000 km/s places the recorded winds among the most extreme AGN outflows. Such speeds mean that the winds carry significant kinetic luminosity relative to the total brightness of the accretion disk. Earlier campaigns on NGC 3783 and related objects have already shown that ultra-fast winds can carry percentages of bolometric brightness – enough to reshape the galaxy's environment in the long term: heating and thinning the gas, suppressing the formation of new stars, and "regulating" the growth of the black hole itself through feedback. The event in NGC 3783 goes a step further because it directly shows how a short-lived episode (flash) can trigger an energetically powerful gust within hours to days.

In practice, this means that energy in galaxy centers is not transferred smoothly and continuously, but in bursts – short episodes during which the black hole "breathes" a strong shock into the surrounding gas. On cosmic timescales, a multitude of such episodes can decide whether a galaxy becomes a "quiet" system without young stars or retains reservoirs of cold gas from which stars can be born.

Comparison with the Sun: why the analogy helps

Scientists have compared this event to coronal mass ejections (CMEs) on the Sun – vast clouds of plasma and magnetic fields that the Sun occasionally ejects into interplanetary space. The analogy is not accidental: in both cases, sudden changes in magnetic topology trigger eruptive ejections. The scales are, of course, completely different. Our stellar system experienced a strong X-class flare on November 11, 2025, followed by a CME with an initial speed of about 1,500 km/s – fast enough to cause a strong geomagnetic storm around Earth a day later. In NGC 3783, however, speeds are about a hundred times greater, and the consequences act on the level of entire galaxies. But the common physical motif – magnetic reconnection and the release of stored magnetic charge in an eruptive act – makes these phenomena easier to understand.

The campaign that enabled the discovery

Such insights are not a result of chance, but of carefully planned multi-year campaigns. NGC 3783 was a key "performance verification target" for the XRISM mission, so in July 2024, multi-day simultaneous observations were coordinated with multiple observatories: XRISM (about 430 ks), XMM-Newton (about 380 ks), NuSTAR (about 220 ks), Chandra/HETGS (about 155 ks), as well as with Hubble's COS spectrograph and fast X-ray platforms Swift and NICER. Such a network of data enabled the first systematic cross-calibration between instruments – essential for bringing measurements of speeds, ionization, and fluxes from different telescopes onto a common energy scale.

Based on these campaigns, extensive papers detailing the kinematics and ionization structure of highly ionized outflows in NGC 3783 have been published. Results suggest a multi-component, "hybrid" wind: part is driven by magnetic mechanisms (reconnection, magnetocentric launching), and part is driven by radiation pressure and thermal instabilities. Interestingly, spectroscopic lines show that the highest degrees of ionization are also of a broader profile – a sign that turbulence increases with ionization. Such "graininess" and layering of the wind are consequences of clumpy structures that likely extend from X-rays to ultraviolet absorption traces registered by Hubble.

Technology behind the discovery: XMM-Newton and XRISM

XMM-Newton (in orbit since 1999) remains the reference instrument for sensitivity and long-duration continuous observations in X-rays. Its EPIC camera precisely tracks brightness changes and captures a broadband spectrum, while the Optical Monitor allows simultaneous measurements in ultraviolet and visible light. XRISM, launched in September 2023, carries Resolve, a micro-calorimeter that measures the energy of every single photon with such precision that it resolves even very narrow spectroscopic details. In the case of NGC 3783, it was Resolve that enabled the separation of multiple absorption components – from modest hundreds of km/s to thousands and tens of thousands of km/s – and the reliable measurement of their ionization states.

What the event tells us about galaxy development

AGNs are the "thermostats" of galactic nuclei. When strong winds blow from them, interstellar gas is heated and dispersed. If this happens often enough, supplies of cold gas – raw material for creating new stars – are depleted. Events like the one in NGC 3783 show that the wind-triggering mechanism is fast and efficient: a single short flash can be enough to trigger a gust that temporarily dampens star-forming processes in the center. A key question here is how often such flashes and winds occur during a galaxy's life and how the accumulated effect of many episodes changes its evolution. This is precisely why measuring kinetic luminosity relative to bolometric brightness is so important: it shows what proportion of energy the AGN "returns" to its environment.

NGC 3783 in the broader context of ultra-fast winds

NGC 3783 is not the only AGN with a "UFO" signature, but it is among the best studied. Even earlier, XMM-Newton and other telescopes recorded very fast winds in a range of galaxies, sometimes up to 0.24c. However, only with the arrival of XRISM has the possibility opened up to precisely distinguish the contribution of magnetic and radiation mechanisms and to bring results onto a common "energy scale" through cross-calibration between multiple observatories. NGC 3783 thus becomes a sort of laboratory for studying the feedback of black holes and galaxies – and a model example of how a short-lived flash turns into global action on the interstellar medium.

The value of observing "at the right time"

The latest event in NGC 3783 highlights the importance of sustained, coordinated campaigns and rapid instrument response. Short X-flashes give no warnings; without simultaneous observations by multiple observatories, the cause-and-effect relationship is easily missed. Here, however, it luckily coincided: XRISM sensed the flash, XMM-Newton tracked it as it faded, and high-resolution spectroscopy immediately showed the formation of wind. Scientifically, this is a turning point: from static "photographs" we are moving to AGN dynamics, with temporal sensitivity allowing the reconstruction of processes as they unfold.

What follows

How often do similar flashes occur? Is 0.2c the upper speed limit in NGC 3783 or a "working" regime sometimes surpassed by even faster gusts? What is the actual mass flux of the winds and how much energy do they deliver to the interstellar medium? How collimated are the winds, and how isotropic? These questions will be answered by longer temporal monitoring and repeated, coordinated recordings of the same objects, combining XRISM's spectral sharpness with XMM-Newton's sensitivity and NuSTAR's hard X-ray insights. Future missions and upgrades to existing instruments should further deepen the understanding of magnetic processes that "switch on" and "switch off" AGN winds.

Touch with Hubble and ultraviolet traces

Absorption line profiles in X-rays show similarities with ultraviolet absorption lines (e.g., Ly-α and C IV) registered by Hubble, suggesting that the winds are of a "grainy" or clumpy character: consisting of many dense "lumps" immersed in a rarer, hot component. Such a structure can affect the efficiency of energy transfer to the environment and how winds mix with interstellar gas. Simultaneous UV and X-ray spectroscopy is therefore invaluable: different ionic traces "capture" different layers of the wind and enable a more complete picture.

Methodological lesson: cross-calibration is necessary

More instruments also mean more systematic differences. XRISM's campaign on NGC 3783 served as a "workshop" for cross-calibration: researchers developed a procedure that takes XRISM/Resolve as the energetic "gold standard" and aligns the responses of other instruments using multi-point splines. This ensures that results from different telescopes can stand next to each other without misleading shifts. Thanks precisely to such background work, today's claims about wind speeds, ionizations, and energetics have a solid instrumentation foundation.

How to "read" the wind spectrum

An X-ray spectrum is not an image but a series of "fingerprints" of elements and their ionization states. When the wind moves towards us, absorption lines are blue-shifted to higher energies; when the gas is more turbulent, the lines are broader. By measuring these shifts and widths, we get the speed and "unrest" of the gas. If we simultaneously track how lines change as the flash fades, we can also calculate the density and distance of absorbing layers from the black hole: a fast reaction of lines means the gas is densely packed and close to the source; a slow reaction points to a rarer or more distant layer. Such tomography in time turns the spectrum into a dynamic map of the wind.

Broader lesson: universality of physics

Paradoxically, the event from the heart of a galaxy 130 million light-years away brings us back – to the Sun. The same concepts of magnetism, reconnection, and plasma connect activities on stellar surfaces and in accretion disks around black holes. The difference is in scale and energy, but the equations are the same. When on November 11, 2025, our star was followed by a CME with an estimated initial speed of about 1,500 km/s, terrestrial technology felt the consequences. When an AGN like NGC 3783 "blows" a hundred or two hundred times faster, entire galaxies change in the long term. That is the beauty of astrophysics: from the laboratory in the solar corona to the edges of accretion disks – nature uses the same laws, just at different scales.

Context of date and source

By December 10, 2025, consolidated summaries and official announcements confirm key figures and interpretations: relativistic speeds of about 0.2c, a timeline where winds form within a day of the X-flash, and the interpretation of magnetic reconnection as the trigger. In doing so, the new analysis builds on multi-year campaigns and recently published papers on XRISM and NGC 3783 that standardized instruments and paved the way for such "live" studies of AGNs. Thus, this event crosses the threshold of sensational news and becomes a reference point for future models of black hole and galaxy feedback.

For readers eager for a deeper dive, it is worth emphasizing that further progress in understanding such episodes is directly linked to the quality and duration of simultaneous observations. Every additional hour of high-resolution spectroscopy on XRISM, every additional night of broadband monitoring on XMM-Newton, and every comparative UV spectrum from Hubble puts another point on the curve connecting the flash, the wind, and their effect on the galactic environment.