[ad_1]
A dramatic frontal collision with a dwarf galaxy, nicknamed the "Gaia Sausage" galaxy, about 10 billion years ago reshaped the structure of our galaxy, the Milky Way, shaping its inner bulb and halo external. suggests
The dwarf did not survive the impact. It's quickly collapsed, and the wreck is now all around us, according to the results.
"The collision shredded the dwarf, letting its stars move in very radial orbits" which are long and narrow like Belokurov needles from the University of Cambridge and the Center for Computational Astrophysics at the Flatiron Institute of New York.
The trajectories of the stars take them "very near the center of our galaxy: it is a telltale sign that the dwarf galaxy has entered a truly eccentric orbit and that its fate has been sealed."
Detailed findings in a series of new newspaper articles, monthly notices from the Royal Astronomical Society, the Astrophysical Journal Letters and arXiv.org describe the key features of this extraordinary event.
Several of the newspapers were run by a Cambridge graduate student, GyuChul Myeong. He and his colleagues used data from the Gaia satellite of the European Space Agency.
This spacecraft mapped the stellar contents of our galaxy, recording the journeys of stars as they travel across the Milky Way.
Thanks to Gaia, astronomers now know the positions and trajectories of our celestial neighbors with unprecedented accuracy.
The stars' paths of galactic fusion have earned them the nickname "Gaia Sausage," says Wyn Evans of Cambridge.
"We traced the velocities of the stars, and the shape of the sausage jumped to our eyes: when the smaller galaxy separated, its stars were thrown into very radial orbits." The Milky Way "said Evans.
The new research also identified at least eight large spherical clusters of stars called globular clusters that were introduced into the Milky Way by the galaxy of sausage.
Smaller galaxies usually do not have their own globular clusters, so the galaxy of sausages must have been large enough to accommodate a collection of clusters.
"While there were many dwarf satellites falling on the Milky Way," said Sergey Koposov of Carnegie Mellon University in Pittsburgh, Pennsylvania, United States.
<! –
->
Source link
