Studying starburst galaxies that form stars at an abnormally fast rate has given astronomers critical clues about the history of the universe. Previously, researchers focused on medium and high-mass star-forming galaxies, but now, dwarf galaxies of low mass are getting the spotlight.
Apparently, dwarf galaxies can give birth to a considerable number of stars, more than anyone thought possible for galaxies with such small masses.
Hakim Atek of the École polytechnique fédérale de Lausanne (EPFL) in Switzerland led a study to analyze dwarf galaxies and see their worth in star-formation. He published his team's surprising results in The Astrophysics Journal on June 19.
"We already suspected these kinds of 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," Atek says.
The dwarf starburst galaxies used to be too small to study, at the amount detail required to be able to calculate the rate of star formation, then researchers took a look at them with the Hubble Wide Field Camera 3 (WFC3). The camera uses infrared and finally gave astronomers an accurate look at star formation by dwarf galaxies. They found that dwarf starburst galaxies can double their mass of stars in only 150 million years.
While that may sound like forever, 150 million years is actually just a walk around a park for the universe. According to NASA, it would take an average-size galaxy 1 to 3 billion years to see as much growth.
Understanding how stars are formed early in the universe lets astronomers glean details about its evolution-one of the most mysterious, most untapped frontiers of science. The evolution of stars in the universe is incredibly complicated and involves processes such as mergers of galaxies, explosions of stars and supermassive black holes that can destroy galactic mass.
These processes have shaped the sky we look at every night, yet they are barely understood. The rapid rate of star-formation by dwarf galaxies is one discovery that is surprising, enticing and perplexing, all at once. It is a reminder of how little we understand the universe, but waves the promise and thrill of discovery in our face. Technologies such as the Hubble Space Telescope and its WFC3 are allowing us to discover more about galactic evolution every day.
