An astronomer from the University of Durham (England), in collaboration 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. LOFAR detects radio waves, as opposed to optical light captured by telescopes like NASA’s Hubble Space Telescope. The result is a fantastic map that reveals details of 4.4 million objects ranging from galaxies to black holes.
A new map of the universe
The map presents a picture of a dynamic universe, with the vast majority of objects located billions of light-years from Earth. We will be able to see around a million objects that have never been seen before with any telescope and almost four million objects that are totally new in radio wavelengths. The rarest objects that have been discovered include colliding clusters of distant galaxies and blazing stars within our Milky Way galaxy.
“It is very exciting to work on this project. Every time we create a map, our screens are filled with new discoveries and objects that have never before been seen by human eyes. Exploring the unknown phenomena that shine in the radio-energy universe is an incredible experience and our team is delighted to be able to publish these maps,” said Timothy Shimwell of ASTRON and Leiden University and co-author of the paper published in the journal Astronomy and Astrophysics.
The task of creating a 3D map of the universe
To produce the map, scientists deployed state-of-the-art data processing algorithms on high-performance computers across Europe to process 3,500 hours of observations that took up up to 8 petabytes of disk space , the equivalent of roughly 20,000 laptops. An overwhelmingly large number.
The telescope used in this task is essentially a large antenna that stretches across Europe, built up from smaller antennas. Although it doesn’t seem very innovative at first glance, in fact the machine that detects higher frequencies is essentially “a big Styrofoam box with a bow-tie antenna inside it”, the real brains of LOFAR are in the processing that follows . “It’s almost like a software telescope,” says Shimwell.
What can be done with this data?
Among the possible studies to be carried out with these LOFAR data, which represent only 27% of the entire survey, include “examining how the largest structures in the universe grow, how black holes form and evolve, the physics that governs the formation of stars in distant galaxies and even detail the most spectacular phases of the life of stars in our galaxy”, clarifies the expert.
Scientists are convinced that the findings are likely to result in many scientific breakthroughs in the future, after other scientists examine each of the individual discoveries.
Dr Leah Morabito, a scientist at the University of Durham, also involved in the LOFAR project, said the work “opens the door to new discoveries”.
whale galaxy
An example of what they have been able to extract from the LOFAR data. It is an optical, X-ray, and radio composite image of the “Whale Galaxy” NGC 4631. In this galaxy, star formation produces hot gas that is visible in X-rays (blue), as well as highly energetic particles that they spiral in the galaxy’s magnetic field that are visible in the LoTSS radio image (orange). The high levels of star formation are possibly due to an interaction with a companion galaxy.
Crédito: Volker Heesen y Michael Stein
Referencia: Timothy. W. Shimwell, et al, The LOFAR Two-metre Sky Survey, Astronomy & Astrophysics (2022). DOI: 10.1051/0004-6361/202142484 , aanda.org/articles/aa/pdf/forth/aa42484-21.pdf
