4.4 million galaxies revealed by scientists in new study

Durham: It is not an unknown fact that our universe has millions of galaxies, of which, we live in one: the Milky Way galaxy. But is it possible to find out how many galaxies are there? In a piece of surprising news, a Durham University astronomer collaborating with a team of international scientists has mapped more than a quarter of the northern sky using the Low-Frequency Array (LOFAR), a pan-European radio telescope.
The study titled, ‘The LOFAR Two-metre Sky Survey (LoTSS)’ was published in ‘Astronomy & Astrophysics’.
The map revealed an astonishingly detailed radio image of more than 4.4 million objects and a very dynamic picture of our Universe, which has been made public for the first time.
The vast majority of these objects are billions of light-years away and are either galaxies that harbour massive black holes or are rapidly growing new stars. Rarer objects that have been discovered include colliding groups of distant galaxies and flaring stars within the Milky Way.
To produce the map, scientists deployed state-of-the-art data processing algorithms on high-performance computers all over Europe to process 3,500 hours of observations that occupy 8 petabytes of disk space – the equivalent to roughly 20,000 laptops.
This data release, which was by far the largest from the LOFAR Two-metre Sky Survey, presented about a million objects that have never been seen before with any telescope and almost four million objects that are new discoveries at radio wavelengths.