Physicists have created a computer model of the epoch of reionization. This is the last great change in the shape of matter in the Universe. It occurred from 550 to 800 million years after the Big Bang. The new model contains feedback processes.
New model of the epoch of reionization
Researchers from the University of Austin in Texas have created a new computer model of the epoch of reionization. They modeled the Universe as it was 600 million years after the Big Bang. At this time, the homogeneous environment was filled with ultraviolet radiation, which ionized matter. The first stars were born, and began to gather into galaxies.
However, it is very difficult to study this process, because little relic radiation has been preserved since then. Therefore, research is conducted mainly on models. The last of them consists of 81,923 dark matter particles and the same number of gas and radiation cells. At the same time, the interaction of these elements was simulated for 300 million years.
To implement such a large-scale project, it took 24,576 graphics and 131,072 conventional processors connected to the Summit supercomputer. At the same time, the calculation process took 10 days.
What is special about the new model?
According to one of the authors of the study, Paul Shapiro, the new model differs from the previous ones not only in its scale. Tracking the evolution of galaxy formation and reionization requires accounting for a mutual feedback process. The radiation coming from the galaxies heats up the environment.
This extra heat, in turn, compresses the gas enough to resist the gravitational pull of nearby galaxies. Otherwise, the gas would fuel star formation; ultimately, this leads to a decrease in the number of luminaries.
In previous models, these processes were considered separately. However, the new simulation is able to take into account the feedback loop as a whole. Thanks to this, it was possible to reconcile some differences between theory and observational data. In particular, the predictions made from previous models did not coincide with the absorption spectrum of quasars. The new model has no contradictions with observations.
According to Рhys.org
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