Small galaxies play 'bigger' role in star creation: Study

Dwarf galaxies actually play a larger role in star creation than previously thought. Astronomers using the Hubble Space Telescope estimated the rate at which stars were created in the tiny galaxies.

Over the past decades, astronomers have been studying the link between the mass of a galaxy and the rate at which stars are formed.

A majority of the studies focused on large and medium galaxies paying little attention to the dwarfs. Hakim Atek of Polytechnique Fédérale de Lausanne in Switzerland says astronomers have always suspected that the small galaxies do contribute to the initial wave of star formation. But this study is the first to quantify the effect that they have. The team used the Wide Field Camera 3 (WFC3) on the orbiting observatory to get data.

Tiny galaxies were common some 10 billion years ago. Astronomers classify some of them as starburst galaxies which are galaxies that produce starts at rates higher than normal. Due to their size, it wasn’t possible to study dwarfs at great distances. WFC3 and infrared spectrometer has enabled astronomers study even the small galaxies.

“These galaxies are forming stars so quickly they could actually double their entire mass of stars in only 150 million years, an incredibly short astronomical timescale,” said Jean-Paul Kneib of EPFL

Most galaxies take up to 3 billion years to achieve the same growth. They sometimes merge with other formations which increases the amount of gases in the system.

Astronomers suggest that starburst galaxies may form after the merging of two galaxies. Others say gravitational forces from other galaxies could be the force behind formation of starbursts.

As stars age and die, the stellar material goes into the surrounding space. Most dwarf galaxies contain a few billion stars as compared to 200-400 billion in our galaxy, the Milky Way.