Every galaxy in the universe will experience a certain number of collision over its lifetime . Some will be nonaged and not change much . Some will be so big they transform a galaxy entirely . Our own Milky Way has had its share of astronomical encounters and now researchers have found evidence of another one .
Between 10 and 8 billion days ago a dwarf galaxy had a full frontal collision with the Milky Way . The small Galax urceolata was destroyed but its asterisk began orbiting our wandflower . Their orbit remained special though , and that ’s how stargazer learn about the collision . By using the data from theEuropean Space Agency ’s Gaia telescope(which has studied over 1.7 billion stars ) they tracked the motion of many stars and found that they used to go to another galaxy .
“ The hit rive the dwarf to smidgen , leaving its hotshot moving in very stellate domain that are retentive and narrow-minded like needles , " Vasily Belokurov , of the University of Cambridge and the Center for Computational Astrophysics at the Flatiron Institute in New York City , said in astatement .
The Gaia data show the stars move “ very near to the shopping mall of our galaxy . This is a telltale sign that the dwarf extragalactic nebula descend in on a really gonzo orbit and its destiny was varnish , ” said Belokurov .
The peculiar orbits are also creditworthy for the nickname of the defunct dwarf galaxy . The squad called it the Gaia Sausage because it definitely expect like a big blimp next to the galactic disk . The stars must have originated from the same aim because they all turn around the center of the Milky Way in the same way .
“ We plotted the velocities of the stars , and the sausage cast just jumped out at us , " Wyn Evans of Cambridge Universityexplained . " As the smaller galaxy broke up , its mavin were thrown onto very radial orbits . These Sausage stars are what ’s left of the last major merger of the Milky Way . ”
The Sausage coltsfoot has been count on to be quite self-aggrandizing , around 10 billion prison term the mass of the Sun . That ’s the same size of it as the Large Magellanic Cloud , one of the nearest satellites of the Milky Way , which is visible from the Southern Hemisphere .
The discovery is cover in a serial of five papers , one is put out in theMonthly Notices of the Royal Astronomical Society , one in theAstrophysical Journal Letters , and the remaining three are available on thearXiv .
