Dark matter can be heated and moved say scientists

Scientists have been researching dark matter for years in an attempt to better understand the universe. Researchers have now found evidence that dark matter can be heated up and moved around as a result of star formation in galaxies. These findings are the first observational evidence for the effect called "dark matter heating."

Scientists working on the project say that the new observational evidence gives clues on what makes up dark matter. Scientists working on the project are from the University of Surrey, Carnegie Mellon University and ETH Z├╝rich. The team searched for dark matter at the center of nearby dwarf galaxies.

Dwarf galaxies are small and faint galaxies that typically orbit larger galaxies and could hold clues to help scientists understand the nature of dark matter. Science believes that dark matter makes up most of the mass of the universe.

The challenge in studying dark matter is that it doesn't interact with light in the same way as normal matter making it only observational via its gravitational effects. The team says that when stars form, strong winds can push gas and dust away from the heart of a dwarf galaxy leaving less mass in the center of the galaxy.

With less mass, how much gravity is felt by the remaining dark matter is impacted. Lead author of the study Professor Justin Read of the University of Surrey said, "We found a truly remarkable relationship between the amount of dark matter at the centers of these tiny dwarfs, and the amount of star formation they have experienced over their lives. The dark matter at the centers of the star-forming dwarfs appears to have been 'heated up' and pushed out." The findings give a new constraint on dark matter models, dark matter must be able to form dwarf galaxies with a range of central densities, and the densities must relate to the amount of star formation.

Professor Matthew Walker, a co-author from Carnegie Mellon University, added: "This study may be the "smoking gun" evidence that takes us a step closer to understanding what dark matter is. Our finding that it can be heated up and moved around helps to motivate searches for a dark matter particle."