Hundreds of black holes may be clustered just 3.3 light-years from the Milky Way’s core.
Key Takeaways:
- Scientists have found evidence that hundreds of black holes may be densely packed around Sagittarius A*.
- X-ray data from the Chandra Observatory suggests at least 12 x-ray binaries near the galactic core.
- These binaries serve as tracers, hinting at the presence of 300-500 isolated black holes nearby.
- The discovery supports long-standing theories that supermassive black holes collect smaller black holes over time.
- Understanding these systems could help scientists learn how black holes form and evolve in dense environments.
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For decades, astronomers have theorized that smaller black holes could be swarming around the supermassive black hole at the center of the Milky Way. Now, new research using data from NASA’s Chandra X-ray Observatory has uncovered the strongest evidence yet that hundreds of these hidden objects may exist within just a few light-years of Sagittarius A* (Sgr A*), our galaxy’s central black hole. The findings, led by astrophysicist Charles Hailey of Columbia University, were published in Nature.
Clues from X-ray Observations
Sgr A* is a colossal black hole located about 26,000 light-years from Earth, and scientists have long suspected that it is surrounded by a dense collection of smaller black holes. However, direct evidence of this population has remained elusive—until now.
Hailey’s team analyzed 12 years of x-ray data and identified a cluster of high-energy x-ray sources concentrated within 3.3 light-years of Sgr A*. Many of these sources match the signature of x-ray binaries, systems where a black hole or neutron star orbits a companion star and feeds on its material, emitting x-rays in the process. Since neutron star binaries often show variability in their x-ray emissions over time, and these sources remained stable, researchers believe they likely contain black holes instead.
At least six of these systems are confirmed x-ray binaries with black hole companions, but astronomers suspect there are hundreds more isolated black holes that remain undetectable. The presence of these binaries suggests that between 300 and 500 solitary black holes could be lurking nearby, blending into the darkness of space.
Unlocking Galactic Evolution
This discovery adds crucial evidence to models suggesting that supermassive black holes grow by pulling in surrounding matter—including smaller black holes. It also sheds light on the formation of x-ray binaries, which may be more common in the dense galactic core than in other regions of the Milky Way.
The findings open new questions about the life cycle of black holes and the conditions that lead to their pairing with stars. Future studies using even more sensitive telescopes could confirm the existence of these hidden black holes, offering deeper insight into how galaxies and their massive central black holes evolve over billions of years.
