Astronomers know that galaxies form through mergers. They’ve been happening since the earliest epochs of cosmic time. Using the Webb telescope astronomers found a massive merger of young galaxies going on about a half million years after the Big Bang. It’s called Gz9p3, one of the earliest and most distant mergers ever witnessed.
JWST spectroscopic observations of the early Universe have uncovered the existence of galaxies existing only 300 million years after the Big Bang. The fact that it’sonly a couple of hundred million years later—as Gz9p3 is doing—suggests that the stars in those galaxies were born and evolved much faster than astronomers expected. That, in turn, puts a whole new spin on events in the earliest epochs of time.The observations made by Boyett and his team show Gz9p3 divided into merging groups.
“When we compared our spectrum analysis with our imaging, we found two different things. The image told us the population of stars was young, but the spectroscopy spoke of stars that are quite old. But it turns out both are correct because we don’t have one population of stars but two,” Boyett said.