Universe’s ‘missing' matter discovered

The cosmological model detailing the density of matter in the Universe has been confirmed by an international team of scientists.

Using a combination of optical and radio telescopes, the team were able to identify the location of a fast radio burst (FRB), that lasted only a few milliseconds in 2015. From this they were able to calculate how much matter the FRB had interacted with since leaving an elliptical galaxy six billion light years away. This is the seventeenth FRB ever detected.

Dr Evan Keane, lead study author, from the Square Kilometre Array Organisation (SKA) said: “It’s the first time we’ve been able to identify the host galaxy of an FRB and the first time a FRB has been used to conduct a cosmological measurement.”

The Universe is believed to be composed of 70% dark energy, 25% dark matter and 5% matter. Scientists have only been able to observe half of the amount of matter in the Universe. By observing the way the FRB travelled through space, the researchers have found the ‘missing’ matter.

On April 19, 2015 the FRB was detected in Australia, with a signal to alert other international partners to begin attempts to identify the direction of the FRB. This set up allowed the telescopes across the world to carry out follow up observations of where the FRB came from using redshift measuring.

FRBs display a frequency-dependent dispersion, this can be used to show how much matter it has interacted with while it has travelled through the Universe. Dr Simon Johnston, study co-author, from the Commonwealth Scientific and Industrial Research, said: “Until now, the dispersion measure is all we had. By also having a distance we can now measure how dense the material is between the point of origin and Earth, and compare that with the current model of the distribution of matter in the Universe. Essentially this lets us weigh the Universe, or at least the normal matter it contains.”

The study was published in Nature.