parts of the milky way can be seen in clear nights, well as a bright streak in the night sky. But when astronomers more Details about our home galaxy want to know, then you don't have it easy. Because you can't look from the outside to the billions of stars existing System. Dust, Gas, or celestial body obscuring the view on the other side of the galaxy.
A big help is researchers, therefore, the "Gaia"program. The astrometry satellite missing, and charted for several years, the milky way, and has collected valuable data, the researchers evaluate.
So astronomers by Amina Helmi of the University of Groningen have received evidence of a gigantic cosmic Crash. Accordingly, the milky way has absorbed around ten billion years ago, a complete other galaxy, the scientists report in the journal "Nature". The traces of the galactic cannibalism are, therefore, still clearly visible today.
photoThe Team of Helmi analyzed the data of around seven million stars, for not only the exact position data is available in all three dimensions, but also the exact self-motion. About 30,000 stars in the so-called Halo of the galaxy also came out clearly: they move opposite to the majority of the stars and also differ in their chemical properties. The researchers conclude that these stars originate from a different galaxy that merged with the milky way.
The idea that our milky way is the product of a merging with satellite galaxies, astronomers study. Surprisingly, the Dimension Gencobahis of the now discovered it crashes for you, however. "We would have expected in Halo stars from merged satellite galaxies," said Helmi, in a communication from your University.
"What we did not expect, is that most of the Halo-come stars actually together from a large merger." In addition to the approximately 30,000 individual stars, astronomers identified a heap of also 13 so-called globular, Structures with millions of stars, which presumably come from the swallowed galaxy.
presentation of the milky way with Gaia data
The data also cast new light on the origin of thick galactic disk, as the researchers explain. The disc which surrounds the Central part of our home galaxy, composed of a thin part, in which, among other things, the spiral arms, and approximately ten times thicker in part, the origin of which is unknown. The now identified cosmic Crash has contributed to the emergence of the thick disk is essential, as Simulation calculations demonstrate. The milky way has a diameter of about 100,000 light-years.
"By reading the movements of stars across the sky, can we rewind now, the history of the milky way back, and a significant milestone in their development", stressed the Gaia project scientist Timo Prusti of the European space Agency Esa.
travel through the solar system you are now leaving the earthMerging galaxies are not isolated in the cosmos, astronomers have spotted in the Depths of space, a number of such events. Also, for the milky way it will not be expected to have been the last Crash: researchers expect to find that our home galaxy will merge in three to four billion years ago, with more than twice as large as the Andromeda galaxy, which is at odds currently with around 120 kilometers-per-second on us.
joe/dpa
Date Of Update: 03 November 2018, 19:00
