- Astronomers have found a giant spiral galaxy with massive jets. They didn’t think a spiral galaxy would be able to retain its shape with such powerful jets.
- Our Milky Way is a spiral galaxy, and it once had jets from its central black hole. But at the moment the black hole is in a quiet stage.
- If our Milky Way produced massive jets, they could spread cosmic rays, gamma rays and X-rays throughout the galaxy, possibly causing a mass extinction on Earth.
The Royal Astronomical Society published this original article on March 21, 2025. Edits by EarthSky.
Cosmic anomaly hints at frightening future for Milky Way
A terrifying glimpse at one potential fate of our Milky Way galaxy has come to light thanks to the discovery of a cosmic anomaly that challenges our understanding of the universe. An international team of astronomers led by CHRIST University, Bangalore, found that a massive spiral galaxy almost 1 billion light-years away from Earth harbors a supermassive black hole billions of times the sun’s mass. And it’s powering colossal radio jets stretching 6 million light-years across.
That is one of the largest known for any spiral galaxy and upends conventional wisdom of galaxy evolution, because such powerful jets are almost exclusively found in elliptical galaxies, not spirals.
It also means the Milky Way could potentially create similar energetic jets in the future. And the cosmic rays, gamma rays and X-rays they produce could wreak havoc in our solar system with increased radiation and the potential to cause a mass extinction on Earth.
A re-think of galaxy evolution
Lead author Joydeep Bagchi of CHRIST University, Bangalore, said:
This discovery is more than just an oddity. It forces us to rethink how galaxies evolve, and how supermassive black holes grow in them and shape their environments. If a spiral galaxy cannot only survive but thrive under such extreme conditions, what does this mean for the future of galaxies like our own Milky Way? Could our galaxy one day experience similar high-energy phenomena that will have serious consequences for the survival of precious life in it?
The peer-reviewed Monthly Notices of the Royal Astronomical Society published the new study on March 20, 2025. In it, researchers unraveled the structure and evolution of the spiral galaxy 2MASX J23453268-0449256. This behemoth is three times the size of the Milky Way.
Cosmic anomaly of a powerful jet in a delicate spiral
The team used observations from the Hubble Space Telescope, the Giant Metrewave Radio Telescope, the Atacama Large Millimeter Wave Array and multi-wavelength analyses. With these observations, they detected an enormous supermassive black hole at the galaxy’s heart. And they also found radio jets that are among the largest known for any spiral galaxy, making it a rare phenomenon.
Traditionally, scientists believed that the violent activity of such colossal jets of supermassive black holes would disrupt the delicate structure of a spiral galaxy.
Yet, against all odds, 2MASX J23453268-0449256 has retained its tranquil nature with well-defined spiral arms, a luminous nuclear bar, and an undisturbed stellar ring. And it does all this while hosting one of the most extreme black holes we’ve ever observed in such a setting.
Adding to the enigma, the galaxy is surrounded by a vast halo of hot, X-ray-emitting gas, providing key insights into its history. While this halo slowly cools over time, the black hole’s jets act like a cosmic furnace, preventing new star formation despite the presence of abundant star-making material.
How this compares to Milky Way
Our own Milky Way has a 4-million-solar-mass black hole – Sagittarius A (Sgr A*) – at its center. But it’s currently in an extremely quiet and dormant state.
But the researchers said if our galaxy’s central black hole ate a a gas cloud, star or even a small dwarf galaxy, that could change. This could potentially trigger significant jet activity. Astronomers call these events Tidal Disruption Events (TDE) and they’ve observed several in other galaxies, but not in the Milky Way.
If large jets like this were to emerge from Sgr A*, their impact would depend on their strength, direction, and energy output, the researchers said.
One pointed near our solar system could strip away planetary atmospheres, damage DNA and increase mutation rates because of radiation exposure. If Earth were exposed to a direct or nearby jet, it could degrade our ozone layer and lead to a mass extinction.
A third possibility is that a powerful jet could alter the interstellar medium and affect star formation in certain regions, which is what has happened in the galaxy the new paper focused on.
Astronomers believe the Milky Way likely had large-scale radio jets in the past. Although it could potentially generate them again in the future, experts aren’t able to say exactly when because it depends on many factors.
Dark matter clues
The team of researchers also discovered that J23453268-0449256 contains 10 times more dark matter than the Milky Way, which is crucial for stability of its fast spinning disc.
By revealing an unprecedented balance between dark matter, black hole activity and galactic structure, the experts said their study opens new frontiers in astrophysics and cosmology.
Co-author Shankar Ray, a PhD student at CHRIST University, Bangalore, said:
Understanding these rare galaxies could provide vital clues about the unseen forces governing the universe, including the nature of dark matter, the long-term fate of galaxies and the origin of life. Ultimately, this study brings us one step closer to unravelling the mysteries of the cosmos, reminding us that the universe still holds surprises beyond our imagination.
Bottom line: Astronomers have spotted a cosmic anomaly: a huge, delicate spiral galaxy with massively powerful jets. What does this mean for our Milky Way galaxy?
Via Royal Astronomical Society
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