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Astronomers discovered an ancient cosmic collision with an object, dubbed the galaxy "sausage", which reshaped the structure of the Milky Way
The accident was a defining event in history of the Milky Way and helped shape its inner bulge and its outer halo, according to a series of studies published in the monthly records of the Royal Astronomical Society and The Astrophysical Journal Letters.
Scientists propose that about 8 billion to 10 billion years ago, an unknown dwarf galaxy broke our own Milky Way . The dwarf did not survive the impact: it quickly collapsed and the wreckage is now all around us.
"The collision shredded the dwarf, letting his stars move in very radial orbits" which are long and narrow like needles, says Vasily Belokurov of the University of Cambridge in the United Kingdom
The Star trajectories take them "very near the center of our galaxy." This is a telltale sign that the dwarf galaxy has entered a truly eccentric orbit. destiny has been sealed. "
Researchers, including those at the University of Cambridge in the United Kingdom, used data from the Gaia satellite of the European Space Agency
that records the stellar journeys of our galaxy.
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 Evans said
The Milky Way continues to collide with other galaxies, such as the dwarf galaxy of Sagittarius, but the galaxy of sausage was much more mbadive. , stars and dark matter was more than 10 billion times the mbad of our Sun.
When the Sausage crushed in the young Milky Way, its piercing trajectory caused a lot of chaos. Milky Way was probably puffy or even fractured following impact and should have regrown.
Sausage debris was scattered all around the inner parts of the Milky Way, creating the "bulge" at center of the galaxy. "Stellar Halo".
Numerical simulations of galactic mashup can replicate these characteristics, says Denis Erkal of the University of Surrey in the United Kingdom
In simulations conducted by researchers, stars of the Sausage galaxy enter orbits stretched. The orbits are further elongated by the growing disk of the Milky Way, which swells and becomes thicker after the collision.
The traces of this galactic remodeling are visible in the trajectories of stars inherited from the dwarf galaxy, says Alis Deason of Durham University in the United Kingdom. "The sausage stars are all about the same distance from the center of the galaxy," says Deason.
These U-turns dramatically decrease the density of the stellar halo of the Milky Way. reverse the directions. This discovery was particularly pleasing to Deason, who predicted this orbital stack nearly five years ago. The new work explains how the stars fell into such narrow orbits in the first place.
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 sausages. 19659002] 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 have been many dwarf satellites falling over the Milky Way during its lifetime, Sergey Koposov, of Carnegie Mellon University in the United States, has studied in detail the kinematics of the stars Sausage and Globular Clusters
(This story was not edited by Business Standard staff and is generated automatically from a syndicated feed.)
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