Latest news with #XRISM
Newsweek
16-05-2025
- Science
- Newsweek
Supermassive Black Hole Fires Gas 'Bullets'—Never Seen Before
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. A supermassive black hole lurking at the heart of a relatively close galaxy is firing off a rapid-fire slew of ultrafast gas "bullets" into the surrounding galaxy. This is the conclusion of an international team of astronomers with the U.S./Japanese X-ray Imaging and Spectroscopy Mission (XRISM), whose spacecraft was designed to observe the hot plasma winds that blow through galaxies. The subject of the study was PDS 456, an active galactic nucleus located some 2.18 giga light-years from the Earth in the constellation of Serpens. The team say that the energy being carried by the "bullets" of wind is far greater than was expected—and could shake up our understanding of how galaxies and their central black holes evolve in tandem. "These estimates disfavor both energy-driving and momentum-driving outflow models, which generally assume that a homogeneous wind affects the galaxy interstellar medium in a spherically symmetric way," the researchers wrote in their paper. An artist's impression of winds from a supermassive black hole. An artist's impression of winds from a supermassive black hole. JAXA What Is a Supermassive Black Hole? Supermassive black holes are behemoths that weigh in at several million to billion times the mass of our own sun. Like their smaller counterparts, their concentrated mass so deforms the fabric of space time that, beyond their "event horizon", nothing—not even light—is able to escape their gravitational pull. Astrophysicists suspect that every galaxy may sport a supermassive black hole at its heart, these objects evolving along with their host galaxy. Exactly what mechanisms underpin this relationship, however, remains unclear—especially given the vast mass and size difference between these paired objects. How Do Central Black Holes Affect Galaxies? Crucial to unpicking this puzzling relationship between a galaxy and its central black hole, the researchers note, is understanding the nature of the powerful outflows of gas expelled from around black holes like a cosmic wind. It is believed that these outflows mediate the linked evolution of supermassive black holes and their host galaxies in two ways. Firstly, they throttle the growth of the holes by slowing the influx of matter for them to feast upon; secondly, they inject vast amounts of energy into their host galaxies, which has the potential to suppress star formation. An illustration of the gaseous wind "bullets" firing out of the supermassive black hole PDS 456. An illustration of the gaseous wind "bullets" firing out of the supermassive black hole PDS 456. Audard et al. / Nature In their study, the researchers used XRISM to observe the gas outflows from PDS 456, finding them to be traveling at some 20–30 percent of the speed of light. In fact, the energy being carried by these winds is more than 1,000 times that transported in galactic-scale winds, suggesting they may have a more significant role than was thought. They also revealed that the winds are composed of five distinct parts, each of which are moving through space at different speeds. According to the researchers, it is this that suggests that either the gas is being ejected periodically—like an explosion from a geyser—or alternatively channeled through gaps in the surrounding interstellar medium. Do you have a tip on a science story that Newsweek should be covering? Do you have a question about black holes? Let us know via science@ Reference Audard, M., Awaki, H., Ballhausen, R., Bamba, A., Behar, E., Boissay-Malaquin, R., Brenneman, L., Brown, G. V., Corrales, L., Costantini, E., Cumbee, R., Trigo, M. D., Done, C., Dotani, T., Ebisawa, K., Eckart, M., Eckert, D., Enoto, T., Eguchi, S., ... XRISM collaboration. (2025). Structured ionized winds shooting out from a quasar at relativistic speeds. Nature.
Newsweek
22-04-2025
- Science
- Newsweek
Cosmic Hit-and-Run Mystery Solved: 'This Is the Missing Piece'
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. Astronomers have solved a cosmic mystery, revealing the long-hidden object that collided with the Perseus cluster in a vast-scale hit-and-run billions of years ago. Composed of thousands of galaxies strung together by their gravity attraction, galaxy clusters are among the most massive structures in the universe. They grow by mergers that are so energetic, they are among the most-powerful events since the Big Bang. Located 240 million light-years from Earth, the Perseus cluster—which has the same mass as 600 trillion suns—was believed to have settled down into a stable, post-merger state. In fact, it was long cited as a textbook example of a relaxed cluster. Developments in astronomical techniques, however, have since revealed that the cluster's internal structure exhibits subtle signs of having undergone a collision. Until now, however, it was unclear exactly what the cluster might have collided with. "This is the missing piece we've been looking for," said paper author and astronomer James Lee of South Korea's Yonsei University 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," Lee added. The Perseus cluster and its lost companion. The Perseus cluster and its lost companion. HyeongHan et al. In their study, Lee and colleagues analyzed archival data collected by the Subaru Telescope, which is at the Mauna Kea Observatory on Hawaii. The telescope can map out the location of otherwise-invisible dark matter by looking for signs of gravitational lensing—the phenomenon where the gravity from massive objects distorts the light from galaxies behind them. In this way, the researchers succeeded in mapping out a massive clump of dark matter, with a mass equivalent to that of some 200 trillion suns, that lies roughly 1.4 million light-years from the core of the Perseus cluster. Moreover, the team found that this newly identified structure appears to be connected to the Perseus cluster's core by a faint "dark matter bridge"—providing direct evidence of the pair's past interaction. "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," said Lee. The researchers' numerical simulations suggest that the newly detected dark matter substructure collided with the Perseus cluster some five billion years ago. "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," concluded Yonsei University astronomer Kim HyeongHan in a statement. Do you have a tip on a science story that Newsweek should be covering? Do you have a question about galaxy clusters? Let us know via science@ Reference HyeongHan, K., Jee, M. J., Lee, W., ZuHone, J., Zhuravleva, I., Kang, W., & Hwang, H. S. (2025). Direct evidence of a major merger in the Perseus cluster. Nature Astronomy.
