The milklike Way is a very chilled galaxy . It meekly produces stars at a pace of one solar raft per yr , and its supermassive opprobrious mess is not having any major outbursts – but it ’s not always been like this . During its formative years , from 13 to eight billion year ago , our beetleweed was a disorderly and exciting seat .
Maosheng Xiang and Hans - Walter Rix from the Max Planck Institute for Astronomy detail the teenaged geezerhood of the Milky Way , its hit with other galaxies , its production of stars , and the creation of heavy component that will over clock time make planet and finally us .
The team used the data point from the European Space Agency ’s Gaia scope that work out theposition and apparent movement of 1.5 billion stars , plus the Large Sky Area Multi - Object Fibre Spectroscopic Telescope in China that has measured the chemic typography of 9 million stars .
Together , the team extracted the location and motion of 250,000 sub - giant stars , whose age can be determine with high accuracy . A wonderful index of what happened , when , and where , in the history of the Milky Way .
The old stars found formed about 800 million old age after the Big Bang . The Milky Way commence from the hit of small , gas - robust protogalaxies merging to shape a drop soma , 100,000 weak - years across and 6,000 promiscuous - years thick . This is called the wooden-headed disk . The Sun is locate in the thin disc , which is within the thick disc and evolved much later .
Based on the reflection from this subject area , published inNature , the thick disk formed from the get - go of the Milky Way 13 billion years ago . That ’s two billion twelvemonth in the first place than antecedently thought . And it also had a very specific pinnacle in genius organization rough 11 billion years ago . This issue seems to be connected to the uniting between the Milky Way and theGaia Enceladus Sausage , a satellite galaxy of the Milky Way .
The gravitational disruption triggered by the high-pitched - speed collision tug petrol clouds together , get to it easier to create raw star . Even after the merger form authorise , the thick disk continues to be accelerator - rich and imprint new maven .
increase star shaping guide to the cosmos of heavier elements , and the subsequent bed cover as adept die . These tend to “ pollute ” newfangled stars and accumulate in the cardinal regions of the galaxy . The observations show instead that the hotshot in the loggerheaded disk have roughly the same composition , suggesting that the gas was well mixed .
Around 8 billion year ago , the gas contracted to what we call today the fragile disc . There ’s still star formation find there , but it ’s more moderate , the sign that the galaxy enter a unagitated and more mature epoch of development .
