Astronomers publish new radio sky survey revealing about 300,000 unknown galaxies

The map was created using data collected through the Low Frequency Array telescope

An international team of astronomers has published a new radio sky survey revealing about 300,000 unknown galaxies in the Universe.

The map was created using data collected through the Low Frequency Array (LOFAR) telescope, installed in the Netherlands and some other countries.

According to astronomers, the telescope observed just 25 per cent of the northern hemisphere in the first part of the sky survey, and only ten per cent of the data has been released to the public domain. The first 26 research papers providing the details of the survey and the results have been published in a special issue of the scientific journal Astronomy & Astrophysics.

The research team claims that the survey mapped around 300,000 radio frequency sources, almost all of which are galaxies in the distant Universe. The radio signals from these sources have travelled billions of light years before arriving at Earth.

The survey also helped astronomers discover some clusters of galaxies merging, causing particles to accelerate.

"With radio observations we can detect radiation from the tenuous medium that exists between galaxies," said Dr Amanda Wilber of the University of Hamburg.

"This radiation is generated by energetic shocks and turbulence. LOFAR allows us to detect many more of these sources and understand what is powering them," she added.

The research team now plans to complete a survey of the entire northern sky, which will reveal 15 million more radio sources in total. Through this survey, astronomers also expect to discover the first massive black holes that came into existence when the Universe was in its early stage.

Radio astronomy is the branch of astronomy which focuses on detecting radio waves emitted by celestial objects, enabling astronomers to discover processes in the Universe that can't be seen through optical instruments.

LOFAR telescope is a big network of radio antennas located in the Netherlands, France, Germany, Sweden, the UK, Poland, Italy and Ireland.

LOFAR is operated by ASTRON, the Dutch astronomy institute in the Netherlands, and is capable of mapping the sky at metre wavelengths. A supercomputer processes the signals obtained through more than 100,000 antennas of the telescope to create a virtual radio telescope dish measuring about 1,900 kilometres in diameter.

"This sky map will be a wonderful scientific legacy for the future," said Carole Jackson, director general of ASTRON. "It is a testimony to the designers of LOFAR that this telescope performs so well."