“We don’t understand how important the impact is alone, but now we have a culprit” that could have created the thick disk, Johnston said.💯 Public chat rooms Explore hundreds of chat rooms or create your own chat room to meet real people online.
👹 Avatars Discover all customization features for your avatar.
🎁 Virtual gifts Surprise your chat buddies or loved one with lovely gifts. Nothing will distract you from chatting and having fun.
In an analogous way, if you shake the Milky Way disk, even billions of years ago, it can take awhile for that response to settle down,” said Johnston.
Belokurov’s group also modeled different collision scenarios, as well as a possible quieter history without significant collisions.
They essentially created high-resolution and multidimensional maps of the Milky Way and used these maps to find anomalous populations of old stars that appear to retain a memory of the long-ago collision.
“The Gaia results really are allowing us to see things in the galaxy that we maybe suspected were there but haven’t seen,” said Kathryn Johnston, an astrophysicist at Columbia University.“It’s interesting because we can finally see what the history of the Milky Way is.” To uncover evidence of the collision so many eons later, astronomers have to work like galactic archaeologists, sifting through myriad sources of surviving information to piece together a story consistent with the available evidence.Both research teams relied on data from the European Space Agency’s Gaia space telescope, which has spent years gathering exceptionally rich biographies of millions of stars — not only their locations and motions, but for many, their brightnesses, temperatures, ages and composition as well.The long-ago collision so thoroughly shook things up that the telltale stars have been strewn throughout the galaxy.“There’s debris everywhere,” said Vasily Belokurov, an astronomer at the University of Cambridge and a leader of one of the two teams.Hints of a dramatic collision had been seen before, but the indications had been inconclusive.