Original Post from Inside Science
Signal hints at possible interactions between ordinary hydrogen and dark matter in the early universe, but some scientists remain skeptical.
(Inside Science) — After spending nearly two decades listening to the skies with radio telescopes, astronomers have finally detected a long-sought-after and subtle signal from the early universe. A group of scientists claim to have found a sign of radiation from the very first generation of stars, only about 180 million years after the Big Bang — just a blink of an eye to the cosmos.
“Other than the cosmic microwave background radiation, this is the earliest observation of any kind in the universe. Compare it to Hubble looking at the first galaxies at 400 million years old; we’re looking at a time roughly half that age,” said Judd Bowman, a cosmologist at Arizona State University in Tempe, Arizona and lead author of the research, published today in the journal Nature.
During an era known as the “cosmic dawn,” the first stars were forged from primordial hydrogen and helium gas. Their ultraviolet light reached free hydrogen gas in the surrounding regions, interacting with the atoms in a way that left a key signature in the radio spectrum from the afterglow of the Big Bang. Looking for signatures like this helps astronomers probe the early moments of the universe when it was first beginning to form its structure.
Artist’s rendering of how the first stars in the universe may have looked.
Image credits: N.R. Fuller, National Science Foundation