Indian-origin astrophysicist discovers mysterious ‘intermediate-mass’ black hole that should not exist
New Delhi | Lakshay Raja: An Indian-origin astrophysicist is among the international team of gravitational-wave astronomers that has discovered a first-of-its-kind elusive intermediate-mass black hole, weighing about 142 solar masses, using a trio of gravitational-wave detectors.
The detected black hole was formed nearly seven billion years ago when two stellar black holes weighing about 66 and 85 solar masses, merged in a region in space-time nearly 17 billion light-years from Earth. The ripples produced in space-time due to the collision traveled across the cosmos at the speed of light and were captured by detectors LIGO and Virgo on March 21, 2019.
Dr. Karan Jani, an astrophysicist from Vadodara, who was part of the team, told Jagran English that the discovery has altered our current understanding of the formation of black holes and how the universe operates.
“It appears that the universe has a preference of making black holes through a way that we still do not fully understand,” Jani told Jagran English. “The discovery has altered our understanding of the universe and reflected gaps in our existing knowledge.”
A black hole is a region of space-time where gravity is so strong that nothing, not even light, can escape from it. While the prediction of a black hole was made nearly 250 years ago, it was not until 1971 that the first candidate Cygnus X-1, was discovered. Astronomers cannot directly observe black holes with telescopes that detect x-rays, light, or other forms of electromagnetic radiation, so they infer their presence by observing their surroundings.
The recent discovery will help astronomers understand how supermassive black holes are formed. Over the past few decades, astronomers have discovered black holes at both ends of the spectrum -- stellar black holes weighing less than 100 solar masses as well as the supermassive ones weighing billion of times the mass of our sun and found at the centre of galaxies — though there was still no concrete evidence about the existence of intermediate black holes.
Scientists do not know for certain how supermassive black holes are formed. One theory suggests that smaller black holes merge over and over, consolidating to become enormous. This school of thought, known as the hierarchical merger model, was marred by the absence of the proof for the existence of intermediate black holes so far.
Does the discovery provide strong evidence in support of the hierarchical merger model of the black hole? “It is something we cannot rule out,” remarked Jani.
The discovery is a triumph for the emerging branch of gravitational-wave astronomy. The branch had emerged in 2016, when the first direct observation of gravitational waves was publicly announced by the LIGO and Virgo collaborations, nearly a hundred years after Albert Einstein predicted the existence of these waves.
“There was a vast universe that was still invisible to us until we came across the gravitational waves,” Jani said. “This is just the start. I believe, in the next twenty years we will be able to answer some of the deepest mysteries surrounding the black holes.”
(Disclaimer: This article has been written by Lakshay Raja, sub-editor, English Jagran)
Posted By: Lakshay Raja