Simulations find ghostly whirlpools of black rear tail of galaxy arm

“Basically, what you do is that you create a pile of particles that represent things like stars, gas and dark matter, and you let them evolve for millions of years,” says Bernet. “Human lives are far too short to attend what is happening in real time. We need simulations to help us see more than the present, which is as one snapshot in the universe. ”

Several other groups already had galaxy simulations they used to do other sciences, so the team asked to see their data. When they found the imprint of the dark matter they were looking for, they checked it in the simulation of another group. They found it, then in a third simulation too.

The spirals of dark matter are much less pronounced than their stellar counterparts, but the team noted a distinct imprint on the movements of black matter particles in simulations. The dark spiral arms are lagging behind behind the stellar arms, forming a sort of invisible shadow.

These results add a new layer of complexity to our understanding of the evolution of galaxies, which suggests that dark matter is more than a passive and invisible scaffold holding galaxies together. Instead, it seems to react to the gravity of the stars of the spiral arms of the galaxies in a way that can even influence the formation of stars or galactic rotation on cosmic time scales. This could also explain the relatively Excess mass found Along a spiral arm nearby in the Milky Way.

The fact that they have seen the same effect in differently structured simulations suggest that these black matter spirals can be common in galaxies like the Milky Way. But following them in the real universe can be delicate.

Bernet says scientists could measure dark matter on the Milky Way disc. “We can currently measure the density of dark matter near us with enormous precision,” he said. “If we can extend these measurements to the whole disc with sufficient precision, spiral models should emerge if they exist.”

“I think these results are very important because it changes our expectations to find out where to look for black matter signals in galaxies,” explains Brooks. “I could imagine that this result could influence our expectations on the way in which dense dark matter is close to the solar district and could influence the expectations for laboratory experiences that try to directly detect dark matter.” This is a goal that scientists have been pursuing for almost 100 years.

Ashley writes on the space for an entrepreneur for the Goddard Space Flight Center of NASA and freelancers in his free time. She holds a master's degree in space studies from the University of Dakota in the North and the scientific writings of Johns Hopkins University. She writes most of her articles with a baby on her lap.