Archiwum zagraniczne East News 2023-11

This most recent image captured by NASA's James Webb Space Telescope offers an unprecedented glimpse into the dense core of our galaxy, revealing features that astronomers are grappling to explain. It is focused on the star-forming area known as Sagittarius C (Sgr C), situated approximately 300 light-years from the Milky Way's central supermassive black hole, Sagittarius A*. Samuel Crowe, an undergraduate student at the University of Virginia in Charlottesville and the principal investigator of the observation team, noted, “There's never been any infrared data on this region with the level of resolution and sensitivity we get with Webb, so we are seeing lots of features here for the first time. Webb reveals an incredible amount of detail, allowing us to study star formation in this sort of environment in a way that wasn’t possible previously.” The galactic centre is considered the most extreme environment in our Milky Way, providing a rigorous test for current theories of star formation, according to Professor Jonathan Tan, one of Crowe’s advisors at the University of Virginia. Among the approximately 500,000 stars captured in the image, a cluster of protostars, stars still in the process of forming and gaining mass, stands out. These protostars produce outflows that glow like a bonfire within an infrared-dark cloud. At the core of this young cluster lies a previously identified massive protostar, over 30 times the mass of our Sun. The density of the emerging stars' cloud is so high that Webb cannot detect light from stars behind it, creating the illusion of a less crowded area when, in fact, it is one of the most densely packed regions in the image. The image also features smaller infrared-dark clouds, resembling voids in the starfield, where future stars are taking shape. The telescope's Near-Infrared Camera (NIRCam) instrument captured large-scale emission from ionized hydrogen surrounding the lower side of the dark cloud, appearing cyan-colored in the image. Crowe highlights the surprise of the vast extent of this region, typically a result of energetic photons emitted by young massive stars, prompting further investigation. The needle-like structures in the ionized hydrogen, arranged chaotically in multiple directions, also pose a mystery for closer examination. Rubén Fedriani, a co-investigator at the Instituto Astrofísica de Andalucía in Spain, adds: “The galactic center is a crowded, tumultuous place. There are turbulent, magnetized gas clouds that are forming stars, which then impact the surrounding gas with their outflowing winds, jets, and radiation. Webb has provided us with a ton of data on this extreme environment, and we are just starting to dig into it.” The galactic centre's proximity, around 25,000 light-years from Earth, enables the study of individual stars with the Webb telescope, offering unprecedented information on star formation and its potential dependence on the cosmic environment compared to other galaxy regions. Questions about the formation of more massive stars at the Milky Way's centre versus its spiral arms' edges are among the inquiries astronomers hope to address. Crowe concludes, “The image from Webb is stunning, and the science we will get from it is even better. Massive stars are factories that produce heavy elements in their nuclear cores, so understanding them better is like learning the origin story of much of the universe.” Where: United States When: 20 Nov 2023 Credit: NASA/ESA/CSA/STScI/Samuel Crowe (UVA)/Cover Images **EDITORIAL USE ONLY. MATERIALS ONLY TO BE USED IN CONJUNCTION WITH EDITORIAL STORY. THE USE OF THESE MATERIALS FOR ADVERTISING, MARKETING OR ANY OTHER COMMERCIAL PURPOSE IS STRICTLY PROHIBITED. MATERIAL COPYRIGHT REMAINS WITH STATED SUPPLIER.**