A quasar’s black hole drives winds 100 times stronger than models predicted

The black hole at the center of quasar H1821+643 has a mass roughly 2.6 billion times the Sun’s. That alone places it among the heaviest objects measured in the nearby universe. But the more startling number is this: the winds it drives outward carry roughly a hundred times the energy that standard models of black hole feedback had predicted — and they push that energy 300,000 light-years into the surrounding intracluster gas, far beyond the boundaries of the host galaxy.

That measurement, made by Japan’s XRISM X-ray telescope and published in Nature Astronomy, fundamentally changes how astronomers must think about the role of supermassive black holes in sculpting their cosmic surroundings.

“Black holes influence the broader cosmic environment through a shock wave of astonishing power,” said Satoshi Yamada of Tohoku University’s Frontier Institute for Interdisciplinary Sciences, who led the research.

How XRISM measured winds across 300,000 light-years

XRISM — the X-ray Imaging and Spectroscopy Mission — is a JAXA/NASA collaboration that launched in 2023. Its core instrument, the Resolve calorimeter, measures X-ray spectra with a precision far beyond earlier satellite observatories. That precision matters because the hot gas filling galaxy clusters — called the intracluster medium — does not radiate in optical light. It glows in X-rays, and the only way to measure how turbulent it is, and therefore how much energy it contains, is through high-resolution spectroscopy of specific emission lines.

Yamada’s team targeted H1821+643 by studying iron-ion emission at 6.7 kiloelectronvolts. When gas moves turbulently, those spectral lines broaden and shift in ways that encode the gas velocity. By mapping this broadening across the cluster, the team reconstructed both the spatial extent and the energy content of the wind-driven disturbance. The result: turbulent energy in the intracluster medium roughly a hundred times greater than estimates built into current models of quasar-mode feedback.

Why 100 times more is a problem for the models

Galaxy clusters are among the most massive gravitationally bound structures in the universe. Left to their own thermodynamics, the hot gas within them would cool, rain down, and trigger runaway star formation. Observations show this catastrophic cooling does not generally happen. The leading explanation is that supermassive black holes in active phases — quasar phases — inject energy into the surrounding gas, keeping it hot. This is quasar-mode feedback, and it is built into virtually every large-scale model of galaxy cluster evolution.

The previous estimates for how much energy quasars inject were based on older X-ray data that could not resolve turbulence in the intracluster medium directly. The XRISM measurement suggests those estimates, repeated across dozens of models, were off by two orders of magnitude.

To put the corrected figure in context: the energy now attributed to H1821+643’s quasar winds is equivalent to several billion simultaneous supernova explosions. The quasar itself sits approximately 3.4 billion light-years from Earth in the constellation Draco. The 300,000-light-year reach of its wind-driven turbulence extends well beyond the host galaxy — roughly three times the Milky Way’s diameter — and covers a substantial fraction of the cluster’s inner volume.

What this result does not settle

One quasar at one moment in cosmic time is a single data point. H1821+643 is a radio-quiet quasar, meaning its relativistic jets are relatively weak compared to radio-loud systems. Whether the extreme turbulence measured here represents typical quasar-mode feedback or an unusually powerful episode cannot be determined from this observation alone.

The team also notes that the XRISM data captures a snapshot, not a time-averaged history. Quasar activity is episodic — black holes cycle between high-accretion and dormant phases over timescales of millions to hundreds of millions of years. The winds currently tearing through the intracluster medium may reflect an active peak rather than a characteristic state.

Perhaps most importantly, the pathway by which quasar winds couple their energy to the intracluster gas remains uncertain. Direct momentum injection, turbulent cascades, and shock heating are all plausible mechanisms. Distinguishing among them requires measuring the gas at multiple scales and temperatures simultaneously — something future missions are designed to do.

Common questions about black hole quasar winds

How do astronomers measure winds from a black hole 3.4 billion light-years away?

Hot plasma near a supermassive black hole glows in X-rays. When that gas moves rapidly, the spectral lines of specific ions shift and broaden in measurable ways. XRISM’s Resolve instrument measures those line shapes with enough precision to deduce both the velocity and the energy of the turbulence.

What is quasar-mode feedback, and why does it matter for galaxy formation?

Supermassive black holes in their active quasar phase release energy into surrounding gas, heating it and preventing runaway star formation. Models of galaxy cluster evolution require this feedback to explain why massive clusters contain far fewer stars than the available gas would allow. The H1821+643 result implies that feedback energy may be far greater than those models assumed.

Could this explain why cluster simulations struggle to match observations?

Possibly. Simulations of galaxy cluster evolution have long disagreed with observed gas distributions and star formation rates in ways that feedback models could not fully resolve. If quasar-mode feedback is two orders of magnitude stronger than assumed, that discrepancy now has a plausible energy source — though the coupling mechanism still needs to be traced.

What comes next for XRISM observations of quasars?

Follow-up observations of other radio-quiet quasar hosts with XRISM are planned for late 2026 and 2027, building the sample needed to establish whether H1821+643 is representative. The team also expects ESA’s next-generation X-ray observatory, NewAthena — with a collecting area roughly ten times larger than XRISM’s — to expand such measurements to hundreds of quasar systems within the next decade.

The paper was published in Nature Astronomy on July 28, 2026. Follow-up XRISM observations targeting additional radio-quiet quasar hosts are scheduled to begin in late 2026 as part of the mission’s ongoing program.

Yamada et al., “Vigorous turbulence driven by quasar-mode feedback in a cluster core,” Nature Astronomy, 2026. DOI: 10.1038/s41550-026-02939-x

Tags: astronomy, black holes, H1821+643, intracluster medium, quasar, XRISM