Supermassive black holes grew from mysterious ‘seeds’ that are yet to be found

• Scientists at NASA have a theory that supermassive black holes grow from groups of smaller black holes.
  
• These ‘intermediate’ black holes are ‘seeds’ for supermassive black holes, supplemented by dust and gas.
  
• But NASA is yet to confirm any sightings of black holes this size.
  

Black holes are one of the most mysterious objects in outer space whose origins continue to perplex scientists.

One theory is that supermassive black holes, which have a mass of billions of Suns, grew from a set of smaller black holes. But these black hole ‘seeds’ — nourished by dust and gas — have never been seen.

In order to find these elusive entities, scientists at the National Aeronautics and Space Administration (NASA) and other space agencies around the world have their telescopes hunting for ‘intermediate’ black holes.

Intermediate black holes

NASA has found hundreds of black holes but none of them fit the bill to be seeds for supermassive black holes.

Smaller black holes that are a result of exploding supernova, are only between 1 to 100 times the mass of the Sun.

On the other hand, supermassive black holes serve as anchors for large galaxies. The Milky Way’s black hole — Sagittarius A* — is equivalent to around 4.1 million Suns.

The intermediate black holes that are meant to be the ‘seeds’ for supermassive black holes would fall somewhere in between. Scientists are currently looking for blackholes that have a mass of 100 to 100,000 Suns.

Invisible or just really hard to find

Scientists believe that during the formative days of the universe, exploding stars were not as ‘polluted’ with heavy elements. So, a supernova explosion could result in an intermediate black hole since the only materials available were pure hydrogen and helium.

It’s possible that all of the intermediate black holes that had to merge have already completed the process, according to NASA. But, it’s also possible that space technology just needs a few more tweaks in order to locate them.

Either way, finding a black hole in itself is a task since they don’t emit any light. The only way black holes show up on specialised telescopes is when they’re feeding and the resulting energy emits light.

Currently, the most promising candidate that NASA has is HLX-1. Discovered in 2009, the black hole has a mass of around 20,000 Suns with a cluster of young stars in its orbit.

See also:
Black holes could be making the universe expand using cores of pure dark energy

Hubble has found a black hole disk that should be non-existent

Millions of black holes are speeding around the Milky Way after being kicked at birth