LOFAR radio telescope delivers a very deep image of the sky
· BehindLines newsroom
An international team based at Leiden University has produced a radio image of the ELAIS-N1 field that it presents as the deepest ever made below 1.28 GHz. According to Phys.org, which relays the release from the Netherlands Research School for Astronomy, the work is led by Jurjen de Jong, a postdoctoral researcher at Leiden Observatory and ASTRON, and has been accepted for publication in Astronomy & Astrophysics. A preprint was posted on arXiv on November 4, 2026.
What the image shows
The data come from the LOFAR network, which observes at low frequencies: 200 hours of observations between 115 and 168 MHz, about 400 terabytes, for an image of 8 billion pixels. It covers a square 2.5 degrees on a side, which Phys.org equates to about 25 times the area of the full Moon. Its sharpness would be enough to pick out a coin about 10 kilometers away, and it is 20 times sharper than the best previous LOFAR image of the region.
The authors report a central sensitivity of about 5.3 microjanskys per beam. Combining the data with earlier, coarser images gives a catalogue of roughly 62,900 distinct radio sources; Phys.org says nearly 63,000. They are mostly active galactic nuclei, powered by matter falling toward a supermassive black hole, and small star-forming galaxies.
Why it matters
The high resolution helps separate overlapping galaxies and tell jet emission apart from emission linked to star formation. Because radio waves pass through dust, the image also offers an unobscured view of star formation in distant galaxies. Co-author Reinout van Weeren says it gives a new window on how these jets interact with their surroundings.
Computing that became affordable
Phys.org reports that better calibration methods have cut processing costs by more than a factor of ten in recent years: the whole set was processed in a few months on the Spider platform, hosted by SURF in the Netherlands. The data are public. The arXiv paper presents the result as a benchmark for future surveys with the LOFAR2.0 upgrade and for the Square Kilometre Array era. The figures quoted are the authors' own.