Dwarf galaxies big contributors in universe's formation

Small galaxies, also known as dwarf galaxies, are responsible for forming a large proportion of the Universe's stars, new observations from NASA's Hubble Space Telescope have revealed.

Studying the formative era of the universe's history is critical to fully understand how these stars formed and how galaxies grew and evolved 3.5-6 billion years after the birth of the universe.

"We already suspected these kinds of galaxies would contribute to the early wave of star formation, but this is the first time we have been able to measure the effect they actually had," said Hakim Atek of Federal Institute of Technology in Lausanne (EPFL) in Switzerland.

"They appear to have had a surprisingly huge role to play," Atek added.

Previous studies of star-forming galaxies were restricted to the analysis of mid or high-mass galaxies, leaving out the numerous dwarf galaxies that existed in this era of prolific star formation.

Astronomers conducted the recent study using data from Hubble's Wide Field Camera 3 (WFC3) to take a further and significant step forward in understanding this formative era by examining a sample of starburst galaxies in the young Universe.

Starburst galaxies form stars at a furiously fast rate, far above what is considered by experts to be a normal rate of star formation.

The infrared capabilities of WFC3 allowed astronomers to finally calculate how much these low-mass dwarf galaxies contributed to the star population in the Universe.

The findings appeared in The Astrophysical Journal.