Radio astronomers go beyond Earth’s ionosphere with new calibration technique Urania

An international team of scientists has created the first detailed low-frequency radio maps of the universe. To achieve this, they developed a new calibration technique that allowed them to bypass interference caused by the Earth’s ionosphere.

The new method was used to study plasma from ancient explosions black holes. The researchers hope that this technology will also be useful for detection in the future egzoplanet It revolves around small stars. Scientists described His technique is published in the journal Nature Astronomy.

This technology allowed astronomers to take clear radio images of the universe at frequencies from 16 to 30 megahertz for the first time. He thought this was impossible because… Ionosphere At an altitude of about 80 km above Earth, it interferes with observations at these frequencies.

Scientists used a telescope Promises In Drenthe, Netherlands. It is currently one of the best low-frequency radio telescopes in the world. To test their method, they examined a series Galaxy clusterswhich had previously been studied in detail only at higher frequencies.

The new images reveal that the radio emissions from these clusters are not evenly distributed throughout the cluster, but rather appear in a dotted pattern. It’s like wearing glasses for the first time and your vision is not blurry anymore – said Christian Groeneveld (Leiden University, Netherlands), who led the research.

The motivation for conducting the research was that at higher frequencies, around 150 MHz, many improvements in calibration have already been made in recent years. We hoped to expand this technology to include lower frequencies, below 30 MHz – said the creator, Renaut van Wieren (Leiden University). And we did it.

Scientists are currently processing more data to map the entire northern sky at lower frequencies.

According to scientists, the new calibration technique makes it possible to study phenomena that were previously hidden. It can be used to detect exoplanets orbiting small stars. Groeneveld concluded: There is, of course, a chance that we might eventually discover something unexpected.

development:
Agnieszka Novak

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Source: Astronomie.nl

Pictured: The left side shows an image of a portion of the sky observed using the best calibration technique ever. On the right you can see the same part of the sky that was made using new technology. More detail is now visible, and once large spots became blurry they now appear as single dots. Source: Lofar/Grunfeld et al