A team of astronomers discovered a rare cluster of galaxies called 'Green Peas' with the help of other scientists through an online project Galaxy Zoo. This discovery gives new insights into how galaxies form stars in the early universe.
Galaxy Zoo users, volunteers use their free time to help classify galaxies in an online picture bank, picking up prominent objects because of their small size and bright blue color. They called those objects Green Peas.
With the help of volunteers to further analyze these strange objects, astronomers discovered that the Green Peas are small, compact galaxies and have extremely fast star formation rates.
'These are the fastest star-forming galaxies we've ever discovered', Carolin Cardamone, Yale's astronomer at Yale and the lead author of the paper, will be published in the next issue of Monthly Notices. of the Royal Astronomical Society , said.
Of the 1 million galaxies in Galaxy Zoo's photo bank, the team only found 250 Green Peas. Cardamone said: 'A person cannot do all these jobs. Even if we can view 10,000 photos, only a few Green Peas will appear and we may not have recognized them as a special kind of galaxy. '
These galaxies, 1.5 to 5 billion light-years away, are 10 times smaller and weigh 100 times smaller than the Milky Way.Surprisingly, despite their small size, these galaxies form stars 10 times faster than the Milky Way.
Kevin Schawinski, a postdoctoral researcher at Yale and one of Galaxy Zoo's founders, said: 'They grow at amazing speeds. Galaxies like these can be very normal in the early universe, but we don't see them today. Learning Green Peas can tell us something about how stars are formed in the early universe, as well as galaxies' evolution.
Green Peas stand out in small size and blue in comparison to regular galaxies - such as the galaxy on the bottom right - which Galaxy Zoo users often see.(Photo: Carolin Cardamone)
Galaxy Zoo volunteers discover Green Peas - they call themselves 'Peas Corps' and 'Peas Brigade' - start discussing these strange objects on the online forum.
Cardamone asked the volunteers - many of them had no astronomical experience - to filter the samples they found to determine which objects were indeed Gree Peas and which were not, based on their colors.By analyzing the light of these objects, Cardamone has identified star formation within galaxies.
Schawinski said 10 Galaxy Zoo volunteers were recognized in the paper for their significant contribution to the research. He said: 'This is a great science project with the direct contribution of ordinary people. This study is a good example of a new scientific approach that can produce results that may not have been achieved without the community's contribution '.
The Galaxy Zoo project was conducted in 2007 by a group of astronomers in the United Kingdom and the United States, including Schawinski.So far, 230,000 volunteers from all over the world have helped classify a million images of galaxies by the Sloan Digital Sky Survey Program. Galaxy Zoo 2, which began in February 2009, allows users to fully analyze more than 250,000 brightest galaxies.
Other authors of the paper include Marc Sarzi (University of Hertfordshire); Steven Bamford (University of Nottingham); Nicola Bennert (University of California, Santa Barbara); CM Urry (Yale University); Chris Lintott (Oxford University); William Keel (University of Alabama); John Parejko (Drexel University); Robert Nichol and Daniel Thomas (University of Portsmouth); Dan Andreescu (LinkLab); M. Jordan Raddick, Alex Szalay and Jan VandenBerg (Johns Hopkins University); Anze Slosar (Lawrence Berkeley National Laboratory Report).