Merger of three jumbo black holes spotted

Merger of three jumbo black holes spotted

Part of: GS Prelims and Mains GS-III – Awareness in Space 

Context: A rare merging of three supermassive black holes has been spotted by a team of astrophysicists in India.

Key takeaways 

• All three merging black holes were part of galaxies in the Toucan constellation.
• The discovery was made using data from the Ultraviolet Imaging Telescope (UVIT) onboard the first Indian space observatory ASTROSAT, the European integral field optical telescope called MUSE mounted on the Very Large Telescope (VLT) in Chile and infrared images from the optical telescope (IRSF) in South Africa.

What is the significance of the discovery? 

• Presence of a third black hole solves the final parsec problem.
  • If two galaxies collide, their black hole will also come closer by transferring the kinetic energy to the surrounding gas. 
  • The distance between the blackholes decreases with time until the separation is around a parsec (3.26 light-years).
  • The two black holes are then unable to lose any further kinetic energy to get even closer and merge. 
  • This is known as the final parsec problem.

How does the presence of a third black hole solve this problem?

• The two black holes can come closer when another black hole or a star passes by and takes away some of their combined angular momentum. 
• Thus, the dual merging blackholes merge with each other in the presence of a third.

What is a black hole?

• A black hole is an object in space that is so dense and has such strong gravity that no matter or light can escape its pull. 
• The boundary at the edge of a black hole is called the event horizon, which is the point of no return. 
• Anything that crosses the event horizon is destined to fall to the very centre of the black hole and be squished into a single point with infinite density, called the singularity.