Scientists using data from India's first dedicated astronomy satellite, AstroSat and NASA's Chandra X-ray Observatory have found that a black…
Scientists using data from India’s first dedicated astronomy satellite, AstroSat and NASA’s Chandra X-ray Observatory have found that a black hole in the binary star system 4U 1630-47 spins near the maximum possible speed.
Relatively smaller black holes are exotic final states of massive star nuclei, astronomers led by the Tata Institute for Basic Research (TIFR) in Mumbai. The gravity of such a collapsing core is so strong that its entire mass is crushed to a point, according to the research approved for publication in The Astrophysical Journal . However, this point can not be seen directly because nothing, not even light, can fly from a region around it, which justifies the object’s name.
Surprisingly, astronomical black holes are the simplest known objects in the universe, as they can be characterized by only two properties, mass and centrifugation speed. Therefore, measurements of these two characteristics are uniquely important for seeking some extreme aspects of the universe, and the basic physics that are related to them, researchers say.
“The scientific measurement of the rotational speed of the black hole, an extremely exotic but simplest object of the universe, comes out close to the maximum possible value,” Sudip Bhattacharyya, TIFR’s Teacher and Chief Researcher in the AstroSat Soft X-ray Telescope (SXT). told PTI . “It is generally very important to prove some extreme aspects of the universe, and the basic physics (such as gravitation theory) that are related to them.”
“Such measurements, especially the spinning speed, are very difficult to do and can only be done by high quality X-ray observations in the correct state of the binary system, where the black hole is gobbling matter from its companion star,” said Mayukh Pahari, who started this work at TIFR, before joining the University of Southampton in Britain.
“SXT and Large Area X-ray Proportional Counter (LAXPC) aboard the first dedicated Indian astronomical satellite AstroSat played a key role in measuring the black hole rotational speed, which was in accordance with the results of our simultaneous Chandra satellite data, “added Bhattacharyya.
” From this first joint AstroSat-Chandra study of a black hole that can lead to further such collaborations, we have found that the black hole in 4U 1
630-47 spins very fast, at a speed that is not m ycket less than the maximum possible speed, making it even more exotic, “added Professor AR Rao of TIFR.
AstroSat was launched in 2015 by the Indian Space Research Organization (ISRO). It is the first dedicated astronomy satellite in India, and SXT aboard AstroSat is the first Indian X-ray telescope.
“In addition to Japan, I think India is the first Asian country to build an X-ray telescope (for example, China could not build such telescope until now),” said Bhattacharyya.
He noted that this “first cooperation between India and the United States with AstroSat and Chandra satellites on black hole studies should open up ways for future such collaborations.”