Post #5191

The 'Little red dots' observed by Webb were direct-collapse black holes The James Webb Space Telescope (JWST) was designed to look back in time and study galaxies that existed shortly after the Big Bang. In so doing, scientists hoped to gain a better understanding of how the universe has evolved from the earliest cosmological epoch to the present. When Webb first trained its advanced optics and instruments on the early universe, it discovered a new class of astrophysical objects: bright red sources that were dubbed "Little Red Dots" (LRDs). Initially, astronomers hypothesized that they could be massive star-forming regions, but this was inconsistent with established cosmological models. In essence, those models predicted that massive galaxies could not have formed less than a billion years after the Big Bang. This led to the theory that they might be quasars, the bright central regions of galaxies powered by supermassive black holes (SMBHs). This also challenged established models, as it was theorized that SMBHs wouldn't have had enough time to form either. In a recent paper posted to the arXiv preprint server, a team of astronomers led by Harvard University demonstrated that the mystery of LRDs could be explained by identifying them with accreting Direct Collapse Black Holes (DCBHs). Their research is based on radiation-hydrodynamic (RHD) simulations developed to model the emission properties of DCBHs, a class of black holes that form directly from clouds of cold gas. This differs from conventional models that predict how black holes form from the collapse of massive stars. These massive stars, a theoretical class known as Population III, were the first stars in the universe, forming from hydrogen and helium with little to no traces of heavier elements (like metals). Source:Phys.org @EverythingScience