An international research effort has unveiled groundbreaking insights into the ancient history of galaxies, shedding light on the fundamental processes shaping our universe. Their findings, recently published in Nature Astronomy, reveal that using the James Webb Space Telescope, a team from Denmark and Australia delved billions of years into the past, back to the era shortly after the Big Bang when galaxies first emerged.
Co-author and astrophysicist Associate Professor Claudia Lagos, from The University of Western Australia’s node of the International Center for Radio Astronomy Research (ICRAR), explained that for over 12 billion years, galaxies adhered to consistent rules governing star formation rates, mass, and chemical composition. It was as though galaxies had a rulebook to follow. However, remarkably, this cosmic rulebook underwent a significant revision during the universe’s infancy.
Perhaps the most surprising revelation was that ancient galaxies produced far fewer heavy elements than expected, challenging our assumptions based on the later galaxies’ fundamental-metallicity relation. Their chemical makeup was roughly four times lower in heavy elements than anticipated.
These findings challenge prior theories of early galaxy evolution, suggesting that early galaxies were closely interconnected with their cosmic surroundings, influenced by their cosmic neighborhood. The most astonishing aspect is that these early galaxies continuously received fresh, pristine gas from their surroundings. This influx of gas diluted the heavy elements within the galaxies, resulting in lower concentrations.
This discovery disrupts existing models of galaxy evolution and raises questions about the mechanisms that shaped the universe during its formative stages. It also opens up new avenues for exploring the cosmic processes that impacted the development of early galaxies.
Source: University of Western Australia