A team of astronomers has discovered and measured hydrogen gas content that fused to form stars and later became galaxies, which are presently located about 4 billion light years away from Earth.
The joint study by researchers from city-based TIFR-National Centre for Radio Astrophysics (NCRA) and Indian Institute of Science, Education and Research (IISER), Mohali, has also confirmed that the efficiency of star formation of galaxies and the cosmological gas mass density have remained significantly unchanged during the last billions of years.
Until now, limitations in the available radio telescopes prevented researchers from capturing the weak hydrogen emissions from the extremely far off celestial bodies.
“Most atomic gas found within galaxies is present in the form of hydrogen and it emits spectral lines at a radiowavelength measuring 21.11 cm. These hydrogen emissions could be added to the field of view of the uGMRT, which offers wide frequency coverage,” said Apurba Bera from IISER, Mohali.
As part of the study, the scientists could make measurements of the atomic gaseous matter from the time when the universe was just two-thirds of its present age.
Jayaram Chengalur, senior scientist at NCRA, said the measurements are crucial and require simultaneous measurements of multiple galaxies.
“The uGMRT’s large bandwidth allowed to cover over 400 galaxies simultaneously,” Chengalur said.