Small dwarf galaxies played a crucial role in illuminating the early Universe, according to recent data from the Hubble and James Webb Space Telescopes. The discovery challenges scientists’ previous assumptions that powerful black holes or large galaxies were responsible for reionizing the cosmos.
In the beginning of the Universe, around 300,000 years after the Big Bang, space was filled with a dense fog of ionized plasma, blocking most wavelengths of light from penetrating. However, the emergence of neutral hydrogen gas and helium led to the birth of the first stars, which produced enough radiation to reionize the Universe.
Recent research suggests that dwarf galaxies, rather than massive black holes or large galaxies, were the primary source of this reionization. By analyzing data from a galaxy cluster called Abell 2744 and other cosmic lens regions, scientists found that these tiny galaxies were not only abundant but also surprisingly bright.
The collective output of these low-mass galaxies is estimated to be four times greater than previously thought for larger galaxies, making them the most prolific producers of energetic radiation in the early Universe. The discovery has significant implications for our understanding of the Universe’s evolution and opens up new questions about the formation and growth of galactic populations.
While more work needs to be done to confirm these findings, this research marks a major breakthrough in the study of reionization and the early Universe.
Source: https://www.sciencealert.com/we-finally-know-what-switched-on-the-lights-at-the-dawn-of-time