Listening to the origins of our universe

The largest radio telescope in the world is located on a mound in Drenthe. LOFAR, the Low Frequency Array, consists of a network of over a hundred thousand antennas that are so powerful that they can even capture low frequencies from the early days of our universe. Dr. Paulus Kruger will speak about the technology behind the world-famous telescope during the RF Technology event.

Register for free for the lecture and event

Kruger is a physicist and engineer by training, a combination that comes in handy in his work as an RF system engineer for the Netherlands Institute for Radio Astronomy (ASTRON), part of the NWO. ASTRON developed LOFAR together with researchers from all over the world, but the core of the super telescope is located in the Netherlands. As an RF engineer, Kruger is mainly responsible for the technical side of the project.

Millions of stars
“LOFAR is not only the largest low frequency-telescope in the world, but also the most sensitive,” Kruger begins enthusiastically. “These low frequencies are particularly interesting, because they carry the furthest, allowing us to look deep into the universe. Thanks to LOFAR, astronomers have discovered millions of objects that we did not know existed.” Most of these objects are in fact complete star systems consisting of millions of stars. Kruger: “With LOFAR, we can observe very interesting phenomena such as pulsating 'stars', enormous explosions and black holes.”

Skymap universe
LOFAR works differently than the classic radio telescope. Instead of one huge dish, LOFAR consists of stations (fields) full of antennas spread over different countries in Europe. By placing the stations in the cloud to each other and to point the antennas at the same point in the universe at the same time, it creates a kind of gigantic European super telescope. The data is collected and analyzed by a very powerful computer in Groningen and converted into images that astronomers can understand.

“With the data we have a detailed skymap of the universe, which has given us much more insight into the composition and origins of our universe,” Kruger explains. “One of the biggest challenges is to interpret the many petabytes of data correctly. Receiving data is one thing, but if you don’t know what the data means, you can’t do anything with it.”

Noise
For a correct interpretation, it is important that the quality of the data is optimal. To achieve this, the team had to eliminate environmental influences as much as possible. Kruger: “A difficult task, because although Drenthe is a sparsely populated province by Dutch standards, there is still a relatively large amount of 'noise' that can influence the operation of the telescope. Think of FM radio, mobile phone communication, aircraft and satellite communication as well as radiation from wind and solar parks. Ideally, you place LOFAR in a remote area in the desert with as few external influences as possible, but that is not desirable for logistical reasons. Without good infrastructure, the telescope cannot function. During my presentation, I will show some techniques that we have developed to be able to detect the weak galactic signals between the enormous amount of 'noise' that is sometimes billions of times stronger.”

Social impact
Despite the technical nature of the presentation, Kruger emphasizes the great social importance of the radio telescope. Kruger: “The technology that forms the basis of LOFAR is not only interesting for scientists and astronomers, but for a wide range of organizations, including commercial companies. For example, Wi-Fi is based on technology that was developed for radio telescopes. The technology of our receivers is also used to improve MRI equipment and telecom companies use it to keep the air 'clean' and prevent unnecessary radio noise. This improves the reception of mobile phones when the signal is weak. In short: LOFAR has a huge impact on our daily lives.”

Come to the lecture
Want to learn more about the technology behind the largest low frequency radio telescope in the world? Then come to the RF Technology event in Leusden. Kruger's plenary lecture is free of charge, but you must register in advance via the website.
NB: Dr. Kruger will speak during the afternoon program at 3 p.m.