• In a vital discovery which may help understand the mystery behind declining star formation activity in the Milky Way, a team of astronomers from the Pune-based National Centre for Radio Astrophysics (NCRA-TIFR) and Raman Research Institute (RRI) in Bengaluru have used the upgraded Giant Metrewave Radio Telescope (GMRT) to measure the atomic hydrogen content of galaxies seen as they were eight billion years ago when the universe was young.
• Galaxies are made up mostly of gas and stars, with gas being converted into stars during the life of a galaxy. Understanding galaxies thus requires determining how the amounts of both gas and stars change with time.
• Star formation activity in galaxies peaked about 8-10 billion years ago and has been declining steadily till today.
• Cause of this decline was unknown as there had been no information regarding amount of atomic hydrogen gas (primary fuel for star formation) in galaxies in these early times.
• Now, Astronomers from National Centre for Radio Astrophysics (NCRA) and Raman Research Institute have measured atomic hydrogen gas content of star forming galaxies.
• Given the intense star formation in these early galaxies, their atomic gas would be consumed by star formation in just one or two billion years. And, if galaxies could not acquire more gas, their star formation activity would decline, and finally cease.
• Measurement of atomic hydrogen content was done by using Giant Metrewave Radio Telescope, set up by NCRA for investigating astrophysical problems ranging from nearby Solar system to edge of observable Universe.
Mains Paper 3: Science and Tech
Prelims level: Giant Metrewave Radio Telescope
Mains level: Read the newsfeed