Scientists create cosmic dawn to understand dark matter

In an attempt to understand dark matter Scientists have used a computer simulation to predict what the very early Universe would be like 500 million years after the Big Bang.

One of the cosmic dawn images shows the Universe 590 million years after the Big Bang

The researchers hope their findings, which highlight star forming galaxies, will improve their understanding of dark matter - a mysterious substance believed to make up 80% of the mass in the Universe.

Lead author, Alvaro Orsi, a research postgraduate in Durham University’s Institute for Computational Cosmology (ICC), said: “We are effectively looking back in time and by doing so we hope to learn how galaxies like our own were made and to understand more about dark matter.
“The presence of dark matter is the key to building galaxies - without dark matter we wouldn’t be here today.”

The images, produced by scientists at Durham University’s Institute for Computational Cosmology, show the “cosmic dawn” - the formation of the first big galaxies in the Universe. The cosmic dawn began as galaxies began to form out of the debris of massive stars which died explosively shortly after the beginning of the Universe. The Durham calculation predicts where these galaxies appear and how they evolve to the present day, over 13 billion years later.

The work combined a massive simulation showing how structures grow in dark matter with a model showing how normal matter, such as gas, behaves to predict how galaxies grow. Gas feels the pull of gravity from dark matter and is heated up before cooling by releasing radiation and turning into stars.
The simulation images show which galaxies are forming stars most vigorously at a given time. Although the galaxies are biggest at the present day, the rate at which they are making new stars has dropped greatly compared with the rate in the early Universe.
The calculations of the Durham team, supported by scientists at the Universidad Catolica in Santiago, Chile, can be tested against new observations reaching back to early stages in the history of the Universe almost one billion years after the Big Bang.