There are some galaxies in the cosmos with tentacles extending like hungry jellyfish, and now researchers have found that active supermassive black holes are at the centre of six of them. A new study released showed that the huge black holes are taking in lots of gas, and what keeps them properly fed is a mechanism that is similar to that which forms jellyfish galaxies.
What makes this discovery surprising is that most supermassive black holes in the universe are thought to be dormant and don’t devour much gas. Hence, the new findings published in Nature can help scientists understand why some black holes take in lots of matter while some don’t – and since black holes and galaxies are interconnected, we can also better understand how galaxies and our Universe has evolved and will continue to evolve.
Jellyfish galaxies actually get their name from their long “tentacles” that are made of gas. According to Swinburne University of Technology, these are formed when the galaxy goes into a cluster of hundreds of galaxies. These clusters are in hot, dense gas which is why when a galaxy falls into it, the gas is being experienced as “wind”. It strips away the gas contained within the galaxy, blowing it into tentacle-like shapes in a process called ram-pressure stripping.
These galaxies are losing gas because of this process, which in turn creates a problem. When gas has been removed, new stars can’t form in the galaxies. This is why this discovery surprised the team at INAF – Astronomical Observatory of Padova. Initially, scientists were looking to learn more about how the gas is stripped away. Instead, they discovered active supermassive black holes in the centre of the Jellyfish galaxies. The team found six of the seven galaxies had an active black hole in its centre. This is unusually higher since only 3 percent of regular galaxies within clusters have active black holes in it.