Latest news with #JamesJee
Yahoo
29-04-2025
- Science
- Yahoo
Scientists Intrigued by Bridge of Dark Matter Inside Huge Galaxy Cluster
The Perseus cluster is a vast swirl of thousands of galaxies, all bound together by gravity. Famed for its unbelievable size — containing the mass of some 600 trillion suns — it also has a reputation for being one of the few "relaxed" galaxy clusters out there: it shows no signs of having undergone a powerful but disruptive merger with another galaxy, which is how these clusters typically grow. In a word, Perseus looks settled down and pretty stable. But that may not be the case, according to an international team of astronomers. As detailed in a new study published in the journal Nature Astronomy, the astronomers have found a "bridge" of dark matter that leads to the center of the cluster, which they believe is the remnant of a massive object slamming into the galactic swirl billions of years ago. If this is evidence of a major merger, it'd mean that Perseus isn't so "relaxed" after all. "This is the missing piece we've been looking for," said study coauthor James Jee, a physicist at University of California, Davis, in a statement about the work. "All the odd shapes and swirling gas observed in the Perseus cluster now make sense within the context of a major merger." Dark matter is the invisible substance believed to account for around 80 percent of all mass in the universe. While we can't interact with dark matter, its gravity appears to be responsible for governing the shapes of the cosmos's largest structures, pulling "normal" matter together around "clumps" of itself to form the galaxies that we see. To make the discovery, the astronomers sifted through data collected by the Subaru Telescope in Japan to look for signs of what's known as gravitational lensing. This occurs when the gravity of a massive object bends the light of more distant sources like a lens, magnifying our view of what lies behind it. By measuring how the light is being distorted, astronomers can infer traits about the object that's causing the lensing. This technique is known as weak gravitational lensing, and can only be used when there's a large number of galaxies that the distortion's incredibly subtle effects can be observed on. It's one of the primary ways that astronomers map the distribution of dark matter throughout the cosmos. Using this technique, the astronomers found a dark matter clump located inside the Perseus cluster around 1.4 million light years away from its center, weighing a colossal 200 trillion solar masses (the entire Milky Way, for reference, weighs about 1.5 trillion solar masses). But the clump clearly was a highly disruptive intruder, because it left behind an enormous dark matter "bridge" linking it to the center of the cluster. According to the astronomers, it's as good as a sign of a collision between the clump and the cluster as it gets. And from simulations they performed, this epic merger occurred some five billion years ago — the echoes of which still affect Perseus' structure to this day. "It took courage to challenge the prevailing consensus, but the simulation results from our collaborators and recent observations from the Euclid and XRISM space telescopes strongly support our findings," lead author HyeongHan Kim, an astronomer at Yonsei University in South Korea, said in the statement. More on dark matter: Scientists Say Dark Matter May Be Giving Off a Signal
Yahoo
28-04-2025
- Science
- Yahoo
Scientists Intrigued by Bridge of Dark Matter Inside Huge Galaxy Cluster
The Perseus cluster is a vast swirl of thousands of galaxies, all bound together by gravity. Famed for its unbelievable size — containing the mass of some 600 trillion suns — it also has a reputation for being one of the few "relaxed" galaxy clusters out there: it shows no signs of having undergone a powerful but disruptive merger with another galaxy, which is how these clusters typically grow. In a word, Perseus looks settled down and pretty stable. But that may not be the case, according to an international team of astronomers. As detailed in a new study published in the journal Nature Astronomy, the astronomers have found a "bridge" of dark matter that leads to the center of the cluster, which they believe is the remnant of a massive object slamming into the galactic swirl billions of years ago. If this is evidence of a major merger, it'd mean that Perseus isn't so "relaxed" after all. "This is the missing piece we've been looking for," said study coauthor James Jee, a physicist at University of California, Davis, in a statement about the work. "All the odd shapes and swirling gas observed in the Perseus cluster now make sense within the context of a major merger." Dark matter is the invisible substance believed to account for around 80 percent of all mass in the universe. While we can't interact with dark matter, its gravity appears to be responsible for governing the shapes of the cosmos's largest structures, pulling "normal" matter together around "clumps" of itself to form the galaxies that we see. To make the discovery, the astronomers sifted through data collected by the Subaru Telescope in Japan to look for signs of what's known as gravitational lensing. This occurs when the gravity of a massive object bends the light of more distant sources like a lens, magnifying our view of what lies behind it. By measuring how the light is being distorted, astronomers can infer traits about the object that's causing the lensing. This technique is known as weak gravitational lensing, and can only be used when there's a large number of galaxies that the distortion's incredibly subtle effects can be observed on. It's one of the primary ways that astronomers map the distribution of dark matter throughout the cosmos. Using this technique, the astronomers found a dark matter clump located inside the Perseus cluster around 1.4 million light years away from its center, weighing a colossal 200 trillion solar masses (the entire Milky Way, for reference, weighs about 1.5 trillion solar masses). But the clump clearly was a highly disruptive intruder, because it left behind an enormous dark matter "bridge" linking it to the center of the cluster. According to the astronomers, it's as good as a sign of a collision between the clump and the cluster as it gets. And from simulations they performed, this epic merger occurred some five billion years ago — the echoes of which still affect Perseus' structure to this day. "It took courage to challenge the prevailing consensus, but the simulation results from our collaborators and recent observations from the Euclid and XRISM space telescopes strongly support our findings," lead author HyeongHan Kim, an astronomer at Yonsei University in South Korea, said in the statement. More on dark matter: Scientists Say Dark Matter May Be Giving Off a Signal
Yahoo
23-04-2025
- Science
- Yahoo
Astronomers discover dark matter 'bridge' linking colliding galaxies: 'This is the missing piece we've been looking for.'
When you buy through links on our articles, Future and its syndication partners may earn a commission. Astronomers have discovered a long-missing element of a galactic collision involving the Perseus galaxy cluster, located 240 million light-years from Earth. This element, a newly detected "subcluster," is 1.4 million light-years to the west of NGC 1275, the central galaxy of the Perseus cluster. These two elements seem to be connected by a faint "bridge" of material. The structural backbone of this bridge is dark matter, the universe's most mysterious "stuff." Dark matter remains effectively invisible by not interacting with light, but its interaction with gravity has helped to shape galactic structures. "This is the missing piece we've been looking for," team member James Jee said in a statement. "All the odd shapes and swirling gas observed in the Perseus cluster now make sense within the context of a major merger."Galaxy clusters are some of the largest structures in the known universe, consisting of thousands of galaxies bound together by gravity. Scientists have long believed that these clusters grow through high-energy mergers that may well be some of the most powerful events in the cosmos since the Big a mass equal to around 600 trillion suns the Perseus cluster has long been considered to be the "poster child" for galaxy clusters. However, this model galaxy cluster has been lacking is the telltale signatures that point toward its growth via was, until now. To tackle this mystery, Jee and colleagues used the Subaru Telescope and its Hyper Suprime-Cam to probe deeper into the Perseus than ever before. This investigation hinged on a phenomenon called "gravitational lensing," first predicted by Albert Einstein in his 1915 magnum opus theory of gravity known as "general relativity." General relativity states that objects with mass cause the very fabric of spacetime (the 4D unification of space and time) to warp, with gravity arising from this curvature. When light from a background object passes through spacetime warped by a massive body, like a cluster of galaxies, its path is curved. This can cause the light to be amplified, thus magnifying that background body, hence the term "lensing."This effect can also reveal things about the lensing body, including its structure. And because dark matter has mass and therefore warps space and diverts light through its gravitational influence, lensing can also reveal the distribution of a gravitational lens' dark matter content. In this case, that process revealed the presence of a massive "clump" of dark matter in the Perseus cluster weighing in at 200 trillion solar masses. This clump is linked to the core of the Perseus cluster by a much lighter but significant dark matter bridge. The team performed simulations of the Perseus cluster, which revealed that this clump collided with the cluster around 5 billion years ago. What remains of this cluster is still sculpting the Perseus cluster today. Related Stories: — Did dark matter help black holes grow to monster sizes in the infant cosmos? — What is dark matter made of? New study bolsters case for 'primordial' black holes — Supermassive black holes in 'little red dot' galaxies are 1,000 times larger than they should be, and astronomers don't know why "This breakthrough was made possible by combining deep imaging data from the Subaru Telescope with advanced gravitational lensing techniques we developed — demonstrating the power of lensing to unveil the hidden dynamics of the universe's most massive structures," Jee concluded. The team's research was published on Wednesday (April 16) in the journal Nature Astronomy.
