Astronomers have discovered a remarkable black hole that has been sending out powerful radio waves for more than eight years, something never seen before.
The unusual object could help scientists better understand how black holes grew in the early universe and how they produce enormous jets of energy.
The discovery comes from an international team of researchers led by the Max Planck Institute for Radio Astronomy in Germany.
Their findings were published in The Astrophysical Journal.
The black hole is located at the center of a spiral galaxy called SDSS J110546.07+145202.4, about 1.8 billion light-years from Earth in the constellation Leo.
Although that sounds incredibly far away, it is relatively close compared with many galaxies from the early universe.
Scientists first noticed that the galaxy’s radio signal suddenly became much stronger. In a short period, its radio emission increased by more than 20 times. Even more surprising, the powerful signal has continued for over eight years without showing signs of fading.
Most radio outbursts from black holes last only a few days or weeks. This makes the newly discovered galaxy the first known example of a black hole producing such a long-lasting radio explosion.
Radio waves are a type of invisible light that can travel across space. Astronomers use radio telescopes to detect these signals and study objects that cannot be seen with ordinary telescopes.
To investigate the mystery, the researchers combined new observations with older data collected across many wavelengths, from low-energy radio waves to high-energy X-rays.
They used several major observatories, including the 100-meter Effelsberg Radio Telescope in Germany, the Australia Telescope Compact Array, and space-based telescopes.
The team believes the radio waves are coming from material falling into the black hole. As gas and dust spiral inward, the black hole grows larger. At the same time, it can launch enormous jets of particles that travel at nearly the speed of light. These jets produce powerful radio waves that can be detected across vast distances.
What makes this black hole especially interesting is that it is relatively small compared with many supermassive black holes, yet it is growing extremely quickly. Scientists think black holes in the early universe may have had similar characteristics.
Because this galaxy is much closer to Earth than ancient galaxies, it gives astronomers a rare opportunity to study processes that may have been common billions of years ago. In a way, it acts like a nearby laboratory for understanding the young universe.
The researchers still do not know exactly why so much material has been falling into the black hole or why the radio outburst has lasted so long. Future observations may provide the answers.
New telescopes, including the Very Long Baseline Array and the upcoming Square Kilometre Array (SKA), will allow astronomers to observe the jet in much greater detail.
Scientists hope these powerful instruments will discover many more long-lasting radio outbursts, helping them better understand how black holes grow, how energetic jets form, and how galaxies evolved in the earliest chapters of the universe.
Source: Max Planck Society.
