An international team of astronomers led by Camille Poitras, a Ph.D. student in the Faculty of Science and Engineering at Laval University, has produced the most detailed X-ray view ever obtained of the jet launched by the supermassive black hole in the galaxy M87. By combining observations from NASA's Chandra X-ray Observatory acquired between 2012 and 2025 with advanced image-processing techniques, the researchers were able to track the evolution of jet structures with unprecedented detail.

Located about 55 million light-years from Earth, M87 hosts the famous supermassive black hole whose image was first released by the Event Horizon Telescope in 2019. As matter falls toward this black hole, part of the released energy is expelled in the form of enormous particle jets that extend thousands of light-years throughout the galaxy.

Until now, X-ray observations could not resolve some jet structures as clearly as observations obtained at other wavelengths. Using an image-processing technique known as deconvolution, the Chandra images now reveal much finer details. The improved X-ray view shows much closer agreement with features seen in optical and infrared observations from the Hubble and James Webb Space Telescopes, allowing astronomers to track their motions more accurately.

"We could already see changes in the jet, but never with this level of detail in X-rays," said Camille Poitras. "Structures that previously appeared blended together can now be distinguished, allowing us to better follow the jet's evolution over more than a decade of observations."

Some structures appear nearly stationary, while others move rapidly through the jet, revealing a more complex and dynamic flow than previously recognized in X-rays. The fastest feature was measured moving at an apparent speed approaching five times the speed of light. This phenomenon, known as superluminal motion, is an optical illusion that occurs when material travels at speeds close to that of light in a direction roughly toward Earth. As a result, astronomers can watch changes unfold on human timescales in a jet located tens of millions of light-years away.

The motions and brightness variations observed in the new X-ray view of the jet represent another step forward in understanding how particles are accelerated to extreme energies. These observations are consistent with computer models in which shocks (like sonic booms from supersonic plans), produced when different parts of the flow collide, plus magnetic fields surrounding the jet, play an important role in driving the structure of the jet.

"These results demonstrate how uniquely powerful Chandra remains for tracking the evolution of extreme phenomena over long timescales," said Gerrit Schellenberger, astrophysicist at the Center for Astrophysics | Harvard & Smithsonian (CfA) and co-author of the study. "They help us better understand how energy released near a supermassive black hole is carried through its jet and deposited into the surrounding galaxy."

The results obtained by Camille Poitras and collaborators are being presented at the 248th meeting of the American Astronomical Society. The study, Resolving the Temporal Evolution of the M87 Jet with ≲0.1-arcsec Chandra Observations, is also available as a preprint on arXiv: https://arxiv.org/abs/2606.13800.

This work was supported by NASA through Chandra Award GO1-22095X issued by the Chandra X- ray Center and by the Fonds de recherche du Québec through awards 346450 and 2003876.