Astronomers have found signs of a medium-sized black hole. These M copies of Friends are almost untraceable yet.
Evidence of a black hole’s presence has been seen in strong bursts of radiation from distant galaxies. Medium-sized black holes are heavier than the small black holes seen around the universe, but they are much less dense than the supermassive black holes found in the centers of galaxies.
Copies of this M mate are hard to find. That’s because they don’t emit radiation like supermassive black holes, and are too large for gravitational-wave detectors to measure.
Astrophysicist Rachel Webster discovered the cosmic mean weight with her team from the University of Melbourne in Australia. They examined data from an archive of 2,700 gamma-ray bursts. These are exceptionally bright flashes of radiation believed to come from massive explosions in other galaxies.
Astronomers searched the data for evidence of gravitational lenses. This phenomenon occurs when a heavy, compressed object deflects light around it.
Researchers found one example of a gravitational lens. In addition, gamma-ray light is deflected by an object of mass 55,000 times the mass of the sun. The very heavy, but not bright, object should be an almost black hole. If so, it is much smaller than the smallest known supermassive black hole, and much larger than the largest “normal” black hole.
“We can’t be 100 percent sure this is a black hole, but all other potential objects are either not compact enough or not common enough,” Webster says. Her team estimates that if the object was truly a black hole, there would likely be one black hole of this mass for every 15 billion cubic light years in the universe.
These types of creatures may be the missing link between tiny black holes and extremely large holes. “We have tiny black holes and we have supermassive black holes, but there was nothing in the middle,” said study co-author James Paynter. Studying all these different sizes can help us understand how supermassive black holes form – an important mystery in astrophysics today.