Monday , April 19 2021

Baby stars can change strange things around dwarf galaxies • The registry

Dark matter may be even more elusive than previously thought, because scientists believe the mysterious material hidden in the heart of the galaxy can be moved with the power of heat.

The process described as "dark matter warming" occurs in dwarf galaxies that are often found around larger galaxies such as the Milky Way. A group of international astrophysicists at the University of Surrey, Carnegie Mellon University and ETH Zurich, studied a total of 16 dwarf galaxies divided into two forms: irregular, amorous and spheroidal. All were in different stages of evolution, and the researchers estimated the amount of dark matter contained in each.

They found that older galaxies with lower star formation rates had denser nuclei of dark matter than younger galaxies. Galaxies, more than six billion years ago, had more than one thousand hundred million solar masses worth dark matter at their center, while the youngest three billion years had "cores" of dark cores. The results were published yesterday in Monthly Notifications of the Royal Astronomical Society.

Researchers believe that the abundant energy emitted by the growing stars warms up in the center of the galaxy and pushes the dark matter away. As the stars form, powerful gullies of electromagnetic radiation emit the gases and dust away, leaving the core less mass. Decreased mass means that there is less gravitational attraction, and dark matter gains enough energy to move away from the center of the galaxy.

"We have discovered a truly remarkable relationship between the amount of dark matter in the centers of these small dwarves and the amount of star formation they have experienced in their lives," said Justin Read, lead author of the study and professor of Physics at the University of Surrey. "Dark matter from the center of the dwarf that forms stars seems to have been" heated "and pushed.

Dark matter accounts for about 27% of the universe, and although it is more abundant than visible baryon, it has not yet been directly detected. It does not interact with light but is affected by gravity. The dynamic nature of the material has led scientists to believe that dark matter is, in fact, "a cool, collision-free fluid that can be" kneaded and moved ". ®

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