Astronomers used fast radio bursts to detect universe's missing matter

In a significant development, atronomers have succeeded in solving a decades-old mystery of "missing matter" by using mysterious fast radio bursts. It is to be noted that this 'missing matter' has been long predicted to exist in the universe, but was not detected by astronomers so far.

According to the researchers, all of the unaccounted normal matter exists in the vast space between stars and galaxies. The findings of the study are published in the journal Nature.

Lead author Associate Professor Jean-Pierre Macquart, from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR) said a team of astronomers have been searching for the missing matter for around three decades

"We know from measurements of the Big Bang how much matter there was in the beginning of the universe. But when we looked out into the present universe, we couldn't find half of what should be there. It was a bit of an embarrassment. Intergalactic space is very sparse. The missing matter was equivalent to only one or two atoms in a room the size of an average office. So it was very hard to detect this matter using traditional techniques and telescopes," he was quoted as saying by Phys.org.

The astronomers managed to directly detect the missing matter using the phenomenon of fast radio bursts, said Associate Professor Macquart. He added that the fast radio bursts were used as "cosmic weigh stations."

"The radiation from fast radio bursts gets spread out by the missing matter in the same way that you see the colours of sunlight being separated in a prism. We've now been able to measure the distances to enough fast radio bursts to determine the density of the universe. We only needed six to find this missing matter," he added.

The missing matter in this case is baryonic, or 'normal' matter—like the protons and neutrons that make up stars, planets and humans. 

Co-author Professor J. Xavier Prochaska, from UC Santa Cruz, said, "The discovery of fast radio bursts and their localisation to distant galaxies were the key breakthroughs needed to solve this mystery."