Real-time detection of an extreme scattering event: Constraints on Galactic plasma lenses

The small matter of our missing bits of universe

4 January 2017

An Australian team has detected lumps of invisible gas in the Milky Way that could be the key to unravelling a universal mystery that scientists have been working on for years.

In a paper published in Science, the scientists described how the lumpy structures worked like lenses and strengthening and weakening radio signals from far-off galaxies.

Using the Australia Telescope Compact Array, they were able to observe variation in radio signals from a distant quasar for more than a year and used that information to estimate the size and shape of the lenses.

“We could be looking at a flat sheet, edge on, or we might be looking down the barrel of a hollow cylinder like a noodle, or at a spherical shell like a hazelnut," Cormac Reynolds from Curtin University said in a press release.

The team believes these structures may provide part of the answer to the missing baryon problem – the approximate five per cent of the universe unaccounted for by known or dark matter.

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References

1. Science 351, 354–356 (2016). doi: 10.1126/science.aac7673