IISc experts detect radio signal from atomic hydrogen in distant galaxy

Source: The post is based on the article “IISc experts detect radio signal from atomic hydrogen in distant galaxy” published in The Hindu on 23rd January 2023.

What is the News?

Astronomers from McGill University in Canada and the Indian Institute of Science (IISc) in Bengaluru have used data from the Giant Metrewave Radio Telescope(GMRT) in Pune to detect a radio signal originating from atomic hydrogen in an extremely distant galaxy.

What is Atomic Hydrogen?

Atomic hydrogen is the basic fuel required for star formation in a galaxy.

When hot ionised gas from the surrounding medium of a galaxy falls onto the universe, the gas cools and forms atomic hydrogen. This then becomes molecular hydrogen and eventually leads to the formation of stars. 

Atomic hydrogen emits radio waves of 21 cm wavelength, meaning the wavelength is a direct tracer of the atomic gas content in nearby and distant galaxies. 

However, this radio signal is feeble and nearly impossible to detect the emission from a distant galaxy using current telescopes due to their limited sensitivity.

What is the Giant Metrewave Radio Telescope(GMRT)?

GMRT is a low-frequency radio telescope that helps investigate various radio astrophysical problems ranging from nearby solar systems to the edge of the observable universe. 

Located at: Pune, Maharashtra

Operated by: National Centre for Radio Astrophysics(NCRA), a part of the Tata Institute of Fundamental Research, Mumbai.

What have the researchers discovered?

Astronomers have used data from the GMRT to detect a radio signal originating from atomic hydrogen in an extremely distant galaxy.

This detection was made possible by a phenomenon called gravitational lensing.