Astronomers have found a new supermassive black hole that is 17 billion times more massive than our sun in an unexpected region. Findings of the study were published in the journal Nature. Following the discovery, researchers believe that the supermassive black holes could be much more common than previously thought.
It lives in ‘a cosmic backwater’
In the past, all known giant black holes were found in massive galaxies clustered in large groups of galaxies. But the newly discovered one is located in a modestly sized galaxy called NGC 1600 that is about 200 million light years from Milky Way. The biggest ever known black hole is 21 billion times more massive than the sun. By comparison, the Sagittarius black hole at the center of Milky Way is just 4 million times the mass of the sun.
Lead author Chung-Pei Ma of the University of California, Berkeley says the new supermassive black hole lives in a “cosmic backwater” or a modest-looking group of galaxies. You expect to find skyscrapers in Manhattan, but this one is like finding a skyscraper in a Kansas wheat field, said Chung-Pei Ma. The black hole was spotted using the 8-meter Gemini North telescope in Hawaii.
How the supermassive black hole formed
Jens Thomas of Max Planck Institute for Extraterrestrial Physics, the co-author of the study, said the center of the galaxy that harbors this black hole is strangely empty. It appears as if the galaxy had eaten up most of its neighbors over time, making it the brightest galaxy in the region. The NGC 1500 outshines other members of the group by at least three times.
As NGC 1600 consumed its neighboring galaxies, its black hole merged with that of others. The supermassive black hole that we observe today would be the result of two or more coalescing into one. Scientists like to study extreme examples like this one because it helps them test existing theories. Astronomers now wonder, “Is this just the tip of an iceberg?” There are several galaxies the size of NGC 1600 in modest-size galaxy groups.