A team of astronomers found evidence of a cataclysmic collision between the Milky Way and a dwarf galaxy some 8 to 10 billion years ago.
The astronomers refer to this galactic crash as a ‘defining event’ in the early history of the Milky Way.
They say the collision between our galaxy, and what is being called the “Sausage” galaxy, reshaped the structure of the Milky Way, helping to form the galaxy’s inner bulge and outer halo.
According to one of the lead researchers, Vasily Belokurov of England’s University of Cambridge and New York’s Flatiron Institute, the dwarf “Sausage” galaxy was ripped to pieces by the ancient cosmic collision, sending its stars out in very radial orbits, which he describes as long and narrow, like needles.
Since data from the European Space Agency’s Gaia satellite was used to in the astronomer’s research, they decided to call the paths the stars from the former dwarf galaxy are making, the “Gaia Sausage.”
So how did the references to a sausage originate?
“We plotted the velocities of the stars, and the sausage shape just jumped out at us. As the smaller galaxy broke up, its stars were thrown onto very radial orbits. These Sausage stars are what’s left of the last major merger of the Milky Way,” said researcher Wyn Evans from the University of Cambridge in a press release.
The astronomer’s findings have been detailed in a series of studies published in the journals, Monthly Notices of the Royal Astronomical Society, The Astrophysical Journal Letters (paper #1 – paper #2 – paper#3) and arXiv.org.