Hidden giant: Black hole spotted far from galaxy's heart
Astronomers have discovered two massive black holes in a galaxy 2 billion light-years away. This marks the first time one of these black holes has been found outside the center of its galaxy.
Key Information
- Two massive black holes have been discovered in a single galaxy.
- One of the black holes is positioned outside the galaxy's center.
- The phenomenon, AT2024tvd, was detected in August 2024.
Astronomers from the University of California, Berkeley, have made an extraordinary discovery. They identified two massive black holes within a galaxy located 2 billion light-years from Earth. Notably, one of these black holes is situated outside the galaxy's center, a rarely observed phenomenon.
The phenomenon AT2024tvd, which facilitated this discovery, was observed on August 25, 2024, by the Zwicky Transient Facility. This led to the detection of the second black hole, which boasts a mass of approximately 1 million solar masses and is located 8,500 light-years from the galaxy's center.
This discovery is significant for further research on black holes. As Yuhan Yao from the University of California explains, the typical location for such objects is the center of a galaxy. However, this discovery challenges that norm by identifying a black hole in an atypical location.
The tidal disruption phenomenon
The second detected black hole was hiding in the outer regions of the central galactic bulge. Astronomers found its trace due to the light radiation caused by the destruction of a star. Because of the tidal forces exerted by the black hole, the star elongated into a stream of matter, some of which began to fall into the black hole, generating radiation in the process.
The presence of a massive black hole wandering alone within a galaxy has two possible explanations. It might have originated from the core of a small galaxy that was previously absorbed by a larger one. It could either be moving along a trajectory that will take it out of the galaxy, or it may be in an orbit that could eventually lead it to merge with the supermassive black hole at the galaxy's center. The second scenario suggests that there were initially three black holes in the galaxy's center; two merged, and the third was ejected to a more distant region of the galaxy.
