fbpx

#Science

ASKAP telescope picks up radio transmission older than our Solar System

By  | 

Scientists using the Australian SKA Pathfinder telescope (ASKAP) have peaked into a little-explored period of the Universe’s history and have picked up a signal transmitted by a galaxy some five billions years ago.

The galaxy was uncovered in radio emission travelling to Earth using CSIRO’s Australian SKA Pathfinder telescope (ASKAP), located at the Murchison Radio-astronomy Observatory (MRO). CSIRO’s Dr James Allison led a research team using ASKAP and the MRO’s unique radio quietness and using a special technique detected a change in radio waves coming from within the bright centre of the galaxy PKS B1740-517, located near the Ara constellation.

The five-billion-year-old radio emission was stamped with the ‘imprint’ of hydrogen gas it had travelled through on its way to Earth.

The gas absorbs some of the emission, creating a tiny dip in the signal. “At many observatories, this dip would have been hidden by background radio noise, but our site is so radio quiet it stood out clearly,” Dr Allison said.

Dr Allison, pictured below, is an affiliate of the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), which is led by Professor Elaine Sadler of the University of Sydney.

The radio galaxy PKS B1740-517. The galaxy has a black hole at centre; jets flowing away from the black hole create the strong radio source detected with ASKAP. The green markings show the position of the radio galaxy PKS B1740-517, the orange blob near the centre of this image.

The radio galaxy PKS B1740-517. The galaxy has a black hole at centre; jets flowing away from the black hole create the strong radio source detected with ASKAP. The green markings show the position of the radio galaxy PKS B1740-517, the orange blob near the centre of this image.

Both researchers are part of a team that will use the absorption technique with ASKAP to find hundreds of galaxies that are up to ten billion light years away and determine how much hydrogen gas they contain.

This will help astronomers understand why star formation, which is fuelled by hydrogen gas, has dropped off in the Universe since its peak 10 billion years ago.

At the UK meeting Dr Allison will also talk about ASKAP’s studies of pulsars (small stars that emit pulsed radio signals) and giant starless clouds of hydrogen gas.

“These latest research findings are demonstrating that ASKAP can do what other telescopes can’t,” Dr Allison said.