New research led by the Swinburne University of Technology shows that the amount of warm carbon suddenly increased by a factor of five over a period of only 300 million years.
The formation of the first galaxies marked an important turning point in cosmic history.
Massive stars released high energy photons which commenced the reionization of the Universe, and stellar nucleosynthesis led to the production of the first heavy elements, which were then released into the surrounding gas via supernova explosions.
However, relatively little is known about the timing of the formation of the first galaxies and how they shaped the properties of their surrounding environments.
“We found that the fraction of carbon in warm gas increased rapidly about 13 billion years ago, which may be linked to large-scale heating of gas associated with the phenomenon known as the Epoch of Reionization,” said lead author Dr. Rebecca Davies, an astronomer at the Swinburne University of Technology and the ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions.
While previous studies have suggested a rise in warm carbon, much larger samples were needed to provide statistics to accurately measure the rate of this growth.
“That’s what we’ve done here. And so, we present two potential interpretations of this rapid evolution,” Dr. Davies said.
“The first is that there is an initial increase in carbon around galaxies simply because there is more carbon in the Universe.”
“During the period when the first stars and galaxies are forming, a lot of heavy elements are forming because we never had carbon before we had stars.”
“And so, one possible reason for this rapid rise is just that we’re seeing the products of the first generations of stars.”
“However, we also found evidence that the amount of cool carbon decreased over the same period.”
“This suggests that there might be two different phases in the evolution of carbon — a rapid rise while reionization…
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