Produced by: Tarun Mishra
Astronomers revisited decades-old data from NASA’s Chandra X-ray Observatory, discovering bright, clumped “knots” in an energy jet from a nearby black hole. These knots appear faster in X-rays than in radio wavelengths, puzzling scientists.
Credit: D. Bogensberger et al. Astrophys. J. (2024), CC-BY 4.0
The study’s lead author, David Bogensberger of the University of Michigan, highlighted that the X-ray view provided details not visible in other wavelengths. This approach, he said, offers new insights into studying black hole jets.
The study, published in The Astrophysical Journal on October 18, coincides with NASA's budget uncertainties, which could impact the Chandra X-ray Observatory's future. NASA’s budget for 2025 remains undetermined, partly depending on the U.S. presidential election outcome.
Researchers analysed 20 years of Chandra’s data on Centaurus A, a galaxy about 12 million light-years from Earth. This active galaxy harbours a supermassive black hole that releases powerful jets of particles.
One knot observed in X-rays reached 94% of the speed of light, faster than the 80% recorded in radio data. This finding suggests X-ray and radio data may capture different aspects of the jet’s dynamics.
Credit: NASA
Centaurus A has been studied since the mid-1800s, but its jet structures became visible only in the 20th century with radio telescopes. Its twin jets, one pointing toward Earth, help scientists observe black hole activity up close.
Over 20 years, the knots showed brightness changes, with one knot brightening and another fading. A similar pattern was previously observed in a black hole in the M87 galaxy, suggesting a potentially common behaviour in such jets.
Future studies aim to determine if the varied speeds and brightness in these jets are intrinsic to the black hole’s jets or influenced by external factors like interstellar matter. Understanding how different wavelengths reflect different jet components may be key, Bogensberger noted.