Wednesday, July 11, 2018

'Sausage' Galaxy Collided with Milky Way 8-10 Billion Years Ago

 According to a new study published by a team of British astronomers, an unknown dwarf galaxy dubbed the 'Sausage' galaxy collided with the Milky Way Galaxy around 8 to 10 billion years ago. This collision left the dwarf galaxy in shreds, leaving behind a wreckage of stars still visible today.
 Unlike other collisions such as the Milky Way's ongoing collision with the Sagittarius dwarf galaxy, the Sausage galaxy was much more massive. Totalling more than 10 billion times the mass of our Sun, the collision left the Milky Way's disk either puffed up or completely fractured following the impact. As for the dwarf galaxy, its detritus would have been scattered across the inner parts of the Milky Way, contributing to the bright centre of the Milky Way galaxy and its surrounding 'stellar halo'.
 “Evidence of this galactic remodeling is seen in the paths of stars inherited from the dwarf galaxy. The Sausage stars are all turning around at about the same distance from the center of the Galaxy,” said Dr. Alis Deason, from Durham University. “These U-turns cause the density in the Milky Way’s stellar halo to decrease dramatically where the stars flip directions.”

Read more about this fascinating story at: http://www.sci-news.com/astronomy/sausage-galaxy-milky-way-collision-06167.html
Or read the studies at the Monthly Notices of the Royal Astronomical Society and the Astrophysical Journal Letters.

Image: Artists impression of the collision between the Sausage Galaxy and the Milky Way Galaxy. Credits: V. Belokurov / Juan Carlos Muñoz / ESO.

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