We Finally Know How The Lights Switched on at The Dawn of Time
Finally, we can know what illuminates the cosmic dawn in the first universe.
According to the data obtained from Hubble and James Webb space telescopes, the origins of free flying photons in the early cosmic dawn were small dwarf galaxies flaming life and cleaned the dark hydrogen of the interjalactic gap. A paper The research was published in February 2024.
“This discovery shows the important role played by ultra -superficial galaxies in the evolution of the early universe.” he said astrophysicist irryna chemerynska Institute D’Astrophysique de Paris.
“They produce ionizing photons that convert neutral hydrogen into ionized plasma during cosmic reionization. It emphasizes the importance of understanding low -mass galaxies in shaping the history of the universe.”
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At the beginning of the universe, in a few minutes Large explosionThe gap was filled with hot, dense ionized plasma fog. How little light did not penetrate these fogs; The photons would disintegrate free electrons floating around and effectively make the universe dark.
As the universe cools down, after about 300,000 years, protons and electrons began to come together to form neutral hydrogen (and a little helium) gas.
Most light wavelengths can penetrate this neutral environment, but there was little in the way of light sources to produce it. However, the first stars of this hydrogen and helium were born.
These first stars gave radiation enough to remove electrons from their seeds and re -monitor the gas. However, at this point, the universe was so enlarged that the gas was scattered and could not prevent the glow of light.
Approximately 1 billion years after the end of the period known as the cosmic dawn, the universe was completely reorganized. Ta-da! The lights were open.
But because there were too many murk in the cosmic dawn and it was too dim and far away in time and space, we had difficulty seeing what happened there.
Scientists think that cleansing should be strong resources responsible for most of them – black holes Accumulation, for example, produces large galaxies in the burning light and star formation (baby stars produce too much UV light).
JWST was partially designed to look at the cosmic dawn and see what is hidden there. He was very successful, and he created all kinds of surprises about this important time in the formation of our universe. Surprisingly, the observations of the telescope now show that dwarf galaxies are key players in reionization.
An international team led by the astrophysicist Judge Atek from the Institute D’Astrophysique de Paris returned to JWST data on a galaxy cluster called Abell 2744, supported by Hubble data.
Abell 2744 is so intense that it fights around space-time and forms a cosmic lens; During this space-time, distant lights traveling to us are enlarged. This enabled researchers to see small dwarf galaxies close to the cosmic dawn.
Later, they used JWST to obtain detailed spectra of these small galaxies. The analysis revealed that these dwarf galaxies are not only the most abundant galaxy species in the early universe, but they are much brighter than expected.
In fact, the team’s research shows that dwarf galaxies are more than 100 to 1 to 100 galaxies, and that their collective outputs are usually four times the assumed ionizing radiation for larger galaxies.
“These cosmic power centers are spreading enough energy to do the job,” Atek said.
“Despite their small size, these low -mass galaxies are productive energetic radiation manufacturers, and their abundance in this period is so important that their collective effects can transform the whole situation of the universe.”
The best evidence for the power behind the reionization, but there is more work to do. The researchers looked at a small patch of the sky; Examples should be sure that there is not only an abnormal dwarf galaxies cluster, but also a representative example of the entire population in the cosmic dawn.
They plan to examine the more cosmic lens areas of the sky to obtain a wider example of early galactic populations. But only in this example, the results are incredibly exciting. Scientists chase the answers to the reonionization as long as we know it. Finally, we’re on the verge of flying fog.
“Now we have entered the undiscovered area with JWST,” he said astrophysicist Themiya Nanayakkara The University of Swinburne Technology in Australia.
“This work, this work, our attempts to draw the evolutionary history of our beginnings, we need to answer more exciting questions.”
The research has been published there Nature.
A version of this article was initially published in March 2024.
