Bypass the disturbance of the Earth’s atmosphere with new calibration technology

ENGINEERINGNET.BE – For the first time, this technology ensures that astronomers can capture clear radio images of the universe at frequencies between 16 and 30 megahertz.

Until now, this was always thought to be impossible, because the ionosphere at an altitude of about 80 km above Earth interferes with observations at these frequencies.

The researchers used the LOFAR telescope located in the Dutch province of Drenthe. It is currently one of the world’s best low-frequency radio telescopes.

To test their technique, they studied a number of galaxy clusters that until now could only be seen in detail at higher frequencies.

The new images show that the radio emissions from these clusters are not evenly distributed over the entire cluster, but there is a localized pattern. “It’s as if you’re wearing glasses for the first time and your vision is no longer blurry,” says study leader Christian Groeneveld of Leiden University in the Netherlands.

The reason for researching the new technology was that many improvements in calibration had already been made in recent years at higher frequencies, around 150 MHz.

“We hoped that we could also extend this technology to lower frequencies, below 30 MHz,” says Reinout van Wieren of Leiden University, who came up with the idea. “This is busy.”

Researchers are currently processing more data so they can map the entire northern sky at low frequencies. They have already studied plasma from ancient black hole explosions with the new method.

According to the researchers, the new calibration technique also makes it possible to study phenomena that were previously hidden. It may be possible to discover exoplanets orbiting small stars. Grunfeld: “There is of course also the chance that we might discover something unexpected.”

Partners in the research are the English SKA Observatory, the Italian Institute of Radio Astronomy, and the German company Hamburger Sternorte.