Extremely massive galaxy proto-supercluster smashes distance record

The newly discovered galaxy proto-supercluster named COSMOS-z3.1-A is the most distant progenitor to a galaxy supercluster ever found. The study used data from the ODIN survey, which captured deep images of a huge area of the Southern Hemisphere sky. The team identified 150 distant protoclusters that formed when the universe was about 1–3 billion years old. They narrowed their focus to two clusters that showed a striking overdensity of galaxies, dubbed COSMOS-z3.1-A and COSMOS-z3.1-C. The ODIN survey provided the 2D coordinates of these structures' locations in the sky. To get a true sense of their galaxy distribution and how they fit into the large-scale cosmic web, a 3D perspective is necessary.

The study used a suite of instruments called spectrographs to measure the distance to an object, allowing scientists to determine its position in 3D. The majority of spectra used in this study were acquired with the Dark Energy Spectroscopic Instrument (DESI), a powerful multi-object spectrograph that can measure the distance to 5,000 different galaxies simultaneously. The team acquired additional spectra using the Gemini Multi-Object Spectrograph (GMOS) on the Gemini South telescope in Chile, as well as the DEep Imaging Multi-Object Spectrograph (DEIMOS) on the Keck II telescope. The team found that both COSMOS-z3.1-A and COSMOS-z3.1-C will evolve to be more massive than the largest known galaxy cluster in our local universe, the Coma Cluster. This is the earliest, most distant proto-supercluster ever found, and it boasts an impressive mass 5,000 times that of the Milky Way galaxy. The team concludes that these ancient protoclusters are very clumpy and irregular and that they lie at the intersections of multiple cosmic web filaments. This is the first time scientists have directly observed such features in the distant universe, and the observations agree with scientists' expectations of how matter is distributed throughout the cosmos.

The study's findings support existing theories of how galaxy clusters evolve and reveal how they are connected to the larger cosmic web. The research is one of the first to produce such detailed 3D maps of multiple distant protoclusters. The maps allowed the team to predict what kind of clusters COSMOS-z3.1-A and COSMOS-z3.1-C will evolve into. The research is part of the Legacy Survey of Space and Time (LSST) by the NSF–DOE Vera C. Rubin Observatory, which aims to create a rich data set that will complement ODIN's deep imaging of the overlapping region of sky. Together, the data will create a deep view of the nearby and distant universe, allowing scientists to study galaxy cluster evolution across cosmic time.

AI-generated summary of the original article — see the source for the full story.