Researchers are pushing the boundaries of our understanding of galaxies by simulating millions of years of cosmic evolution. According to physicist Bernet, these simulations involve creating numerous particles that embody various cosmic entities, including stars, gas, and dark matter. “Human lives are much too short to witness this happening in real time. We need simulations to help us see more than the present, which is like a single snapshot of the Universe,” he explains.
The research team collaborated with other groups that had previously conducted galaxy simulations for different scientific projects. Upon examining the data from one of these groups, they identified a dark matter pattern they had been searching for. This pattern was subsequently found in additional simulations, reinforcing their initial findings.
While the dark matter spirals are less distinct than the spirals formed by stars, the researchers noted a specific influence on the movement of dark matter particles in their simulations. The dark spiral arms tend to lag behind their stellar counterparts, creating a subtle but significant “shadow” effect.
This discovery adds depth to our comprehension of galactic evolution, indicating that dark matter may play a more active role than previously thought. Rather than simply being an invisible framework, dark matter appears to interact with the gravitational pull from stars, potentially affecting star formation rates and the rotation of galaxies over vast timescales. This phenomenon may also provide insight into a recently identified excess mass along a nearby spiral arm of the Milky Way.
The replication of these effects across various simulation architectures suggests that dark matter spirals could be a common feature in galaxies akin to the Milky Way. However, detecting these spirals in the actual cosmos poses a considerable challenge.
Bernet suggests that researchers could measure the dark matter density within the Milky Way’s disk. “We can currently measure the density of dark matter close to us with significant precision,” he notes. “If we can extend these measurements across the entire disk with enough accuracy, spiral patterns should become evident if they exist.”
Brooks emphasizes the importance of these findings, stating that they may redefine how scientists search for dark matter signals in galaxies. “I could imagine that this result might influence our expectation for how dense dark matter is near the solar neighborhood and could impact expectations for lab experiments that aim to detect dark matter directly,” he states, highlighting the longstanding quest to uncover the nature of dark matter.
Ashley writes about space for a contractor at NASA’s Goddard Space Flight Center during the day and freelances in her spare time. She holds master’s degrees in space studies from the University of North Dakota and science writing from Johns Hopkins University. Most of her writing is done while balancing a baby on her lap.
