Scientists want to see the light of the “Cosmic Dawn” – the period at the beginning of the Universe when the first stars ignited. It is expected that the giant Square Kilometre Array (SKA) radio telescope will be able to do this.
Cosmic Dawn
Scientists have calculated what the light of the “Cosmic Dawn” would look like for the giant Square Kilometre Array (SKA) telescope. The latter is currently under construction and will consist of a huge number of antennas that will work as a single unit and have the same sensitivity as a single spherical mirror with a diameter of 3,000 meters.
“Cosmic Dawn” is the term scientists use to describe the moment after the “dark ages,” the time when the reionization of interstellar hydrogen had already taken place, space had become transparent, and the light of newborn stars was able to travel freely through it. This occurred 200-600 million years after the Big Bang. Scientists are particularly interested in hydrogen radiation at a wavelength of 21 cm.
Wavelength shift
Since the Cosmic Dawn, the expansion of the Universe has caused the frequency of photons flying through space to shift toward the red end of the spectrum. And now this signal can be heard at a wavelength of 106-196 Hz.
However, the signal is very weak. It is precisely in this range that sources in both the Milky Way and other galaxies actively emit radiation. That is why researchers had to calculate how they would all appear to SKA in order to understand whether it would see anything other than them.
Research shows that if we take into account all sources that emit at these frequencies with an intensity of up to 1 microJy, then it will be possible to see the light of the “Cosmic Dawn” behind them.
According to phys.org
