Hubble Reveals Powerful Starbursts in Dwarf Galaxies Had a Large Role in the Early Universe

NASA has made a startling discovery when it comes to the early history of the universe. The Hubble Space Telescope has revealed that powerful starbursts in dwarf galaxies may have had a larger role to play that previously expected.

Galaxies across the universe are still forming new stars, but the majority of stars were formed between two and six billion years after the Big Bang. Looking back at this time period is therefore crucial for understanding how these stars formed and how galaxies have evolved since then.

That's why researchers decided to take a closer look at the early universe. The researchers used data from Hubble's Wide Field Camera 3 (WFC3) to examine a sample of dwarf galaxies in the early universe. In particular, they looked at starburst galaxies from within this sample. Starburst galaxies form stars at a furious pace, churning out new celestial bodies at a rapid rate.

"We already suspected that dwarf starbursting galaxies would contribute to the early wave of star formation, but this is the first time we've been able to measure the effect they actually had," said Hakim Atek, one of the researchers, in a news release. "They appear to have had a surprisingly significant role to play during the epoch where the universe formed most of its stars."

In fact, scientists actually weren't able to properly study these distant, small galaxies. Yet the highly sensitive infrared capabilities of WFC3 and its unique grism spectroscopy mode have changed that, allowing astronomers to examine low-mass dwarf galaxies in the distant universe.

"These galaxies are forming stars so quickly that they could actually double their entire mass of stars in only 150 million years-this sort of gain in stellar mass would take most normal galaxies one to three billion years," said Jean-Paul Kneib, one of the researchers, in a news release.

The findings reveal what sort of activity was occurring in the early universe. Not only that, but it shows that dwarf galaxies were important for star formation at this time. This, in turn, gives astronomers a better understanding of galaxy evolution over time.

The findings are published in The Astrophysical Journal.