Star-forming galaxies help in understanding 'universe'

Scientists have made a better understanding of how the universe began, by studying radiation leaks of star-forming galaxies in the universe.

The researchers from the Johns Hopkins University used the radiation leak measurement method to help find the ideal star-forming galaxy that contained holes in its cold gas cover. Studying the radiation that seeped through these holes had been a conundrum for scientists for years.

Sanchayeeta Borthakur, an assistant research scientist, said that it was like the ozone layer, but in reverse. The ozone layer protected us from the Sun's radiation but they wanted the gas cover the other way around. The star forming regions in galaxies were covered with cold gases so the radiation could not come out. If they could find out how the radiation got out of the galaxy, they could learn what mechanisms ionized the universe.

Borthakur said scientists knew that these leaky galaxies existed, but finding one had been a problem. This made it difficult for researchers to have a clearer understanding of how the reionization process worked.

For star-gazers, reionization is core to the history of the cosmos as it marked the birth of the very first stars and galaxies.

Moments after the Big Bang, the hot, newly born universe began to expand and quickly cool. Several hundred thousand years later, free proton and electron particles in the universe began to connect to each other and form neutral hydrogen atoms. The neutral gas began to collapse into the first stars and galaxies, which then began to radiate brightly.

Using observations made with the Cosmic Origins Spectrograph onboard the Hubble Space Telescope, the research team found the right galaxy to study. In the study, the researchers credit a combination of unusually strong winds, intense radiation and a massive, highly star-forming galaxy for proving the validity of the indicator.

This method first created by Heckman in 2001, could sort out what gas was present and also accurately measured the percentage of holes in the gas cover, said Borthakur.

The study is published in the journal Science.