Astronomers have identified 15 dense hubs of star formation within a galaxy located approximately 930 million light-years from Earth. This discovery, published in Nature Astronomy, offers significant insights into the early stages of galaxy formation. The galaxy, nicknamed "Cosmic Grapes," exhibits a striking visual of bright, filamentary clumps resembling a celestial grapevine.
These star-forming regions were observed using a combination of the James Webb Space Telescope (JWST) and the Atacama Large Millimeter/submillimeter Array (ALMA). The research team utilized gravitational lensing, where a massive foreground galaxy magnifies the light from the distant galaxy, to achieve an exceptionally detailed view. This technique revealed structures previously hidden from less powerful instruments. Earlier observations with the Hubble Space Telescope had shown this galaxy as a smooth, uniform disk. However, the enhanced resolution from JWST and ALMA unveiled a more complex reality: a rotating galaxy filled with massive, tightly packed stellar nurseries. This finding establishes a link between a galaxy's internal structures and its overall mass assembly, suggesting that many galaxies appearing smooth in previous observations might possess similar, undetected substructures.
The "Cosmic Grapes" galaxy aligns with the typical characteristics of galaxies in the early universe in terms of its star formation rate, mass, size, and chemical composition, implying that such clumpy structures could be more common than previously assumed. The extensive study involved over 100 hours of dedicated telescope time. This discovery challenges existing theoretical models, as current simulations struggle to replicate the high number of clumps observed in rotating galaxies from this period, suggesting a need to revise our understanding of feedback processes and structure formation in nascent galaxies. The "Cosmic Grapes" provide a unique window into the complex architecture of the early universe, potentially heralding a new era of understanding galaxy evolution. Future observations will be crucial in determining the prevalence of such clumpy structures in the universe's youth.