Astronomers have discovered more than 200 “baby” galaxy clusters in the distant universe that may shed light on how galaxies formed. The universe is 13.8 billion years old and contains more than 100 billion galaxies. But scientists are still unsure how galaxies form and evolve over time. The discovery will also help understand the nature of the dark matter and how it influences galaxies.
Planck and Herschel observe galaxy clusters
Astronomers said these baby galaxies were formed only about three billion years after the Big Bang 13.8 billion years ago. The discovery was made using the European Space Agency’s Planck and Herschel telescopes. Planck used the cosmic microwave background signals to create a map of the radiation left by the Big Bang.
Then astronomers used Herschel to zoom in on some of the galaxy clusters captured by Planck. It allowed them to examine what is believed to be the precursor to galaxies. The oval shape in the above image is the entire sky, as captured by the Planck mission. The band running through the middle is similar to the dust in our own Milky Way galaxy.
The black dots in the above photo are the galaxy cluster candidates identified by Planck and further studied by the Herschel mission. Hervé Dole, the lead author of the study, said in a statement that it was a huge surprise to find “so many intensely star-forming, dust galaxies in such concentrated groups.” Dole said it could be “a missing piece of cosmological structure formation.”
These baby galaxies are ‘star factories’
Stars and galaxies came to life in the early universe, but later assembled into large clusters. Cluster formation led to the collapse of massive amount of matter under the influence of gravity, which triggered the formation of new stars and galaxies, according to NASA. The newly discovered baby galaxy clusters are “star factories,” producing new stars at a prodigious rate.
Astronomers said that the baby galaxies are creating new stars from dust and gas at a rate of 1,500 solar masses per year. It means each of them is creating 1,500 new stars the size of our sun every year. According to the European Space Agency, our Milky Way averages only one solar mass per year.