Milky Way survived ancient heat wave because of dark matter

Washington, July 1 (ANI): A new theory by scientists says that our Milky Way galaxy survived intense heat generated by the "ignition" of the Universe about half-a-billion years after the Big Bang, because it was already immersed in a large clump of dark matter that trapped gases inside it.

Tiny galaxies, inside small clumps of dark matter, were blasted away by the heat that reached approximate temperatures of between 20,000 and 100,000 degrees centigrade, according to the scientists, including experts at Japan's University of Tsukuba.

The researchers said that the early Milky Way, which had begun forming stars, held on to the raw gaseous material from which further stars would be made.

This material would otherwise have been evaporated by the high temperatures generated by the "ignition".

Using computer simulations carried out by the international Virgo Consortium (which is led by Durham), the scientists examined why galaxies like the Milky Way have so few companion galaxies or satellites.

Astronomers have found a few dozen small satellites around the Milky Way, but the simulations revealed that hundreds of thousands of small clumps of dark matter should be orbiting our galaxy.

Dark matter is thought to make up 85 per cent of the Universe's mass and is believed to be one of the building blocks of galaxy formation.

The scientists said the heat from the early stars and black holes rendered this dark matter barren and unable to support the development of satellite star systems.

According to Joint lead investigator Professor Carlos Frenk, Director of the Institute for Computational Cosmology, at Durham University, "The validity of the standard model of our Universe hinges on finding a satisfactory explanation for why galaxies like the Milky Way have so few companions."

"The simulations show that hundreds of thousands of small dark matter clumps should be orbiting the Milky Way, but they didn't form galaxies," he explained.

"We can demonstrate that it was almost impossible for these potential galaxies to survive the extreme heat generated by the first stars and black holes," he added.

"The heat evaporated gas from the small dark matter clumps, rendering them barren. Only a few dozen front-runners which had a head start on making stars before the Universe ignited managed to survive," he further added.

By providing a natural explanation for the origin of galaxies, the simulations support the view that cold dark matter is the best candidate for the mysterious material believed to make up the majority of our Universe. (ANI)