Scientists now know our exact age GalaxyThe formation of certain areas dating Milky Way Just 800 million years after the Big Bang.
In a new article published Wednesday in the magazine NaturalAstronomers Mao Zheng Chiang and Hans-Walter Ricks from the Max-Blanc Institute AstronomyOne study was used for nearly a quarter of a million Stars To better understand the very long galactic life cycle, the development of the Milky Way over time is shaped by the development of knowledge about stellar life cycles.
The Milky Way spiral disk can be divided into two populations, the thinner, inner disk of younger stars, belonging to our Sun, and a thicker, slightly older disk of stars that extend beyond the galactic spiral plane. There is usually a halo around the galaxy, which is a rare population of older stars.
Xiang and Siks found that the thick disk began to form about 13 billion years ago or 800 million years after the Big Bang, while the inner galaxy formed about two billion years later. 8 to 11 billion years ago the assembly of the inner halo took place through the ancient connection of the Milky Way with a dwarf galaxy, the dwarf galaxy Gaia-Enceladus, which is largely connected to our galaxy.
To make the discovery, the researchers used stellar clocks: low-mass stars in the “sub” phase. When a low-mass star like the Sun begins to emit hydrogen, its center contracts as a kind of opposite weight to its own gravitational pressure, pushing it towards collapse. Then, the hydrogen around the star ignites, causing the star to enter the giant phase, but as long as it is sublime, the star’s luminosity is closely related to its age.
Unfortunately, stars spend only a few million years in the subunit phase, so massive study of stars is needed to find enough stars to provide useful data. Xiang and Six therefore used data from the LAMOST (Large Celestial Area Fiber Multi-Object Spectroscopic Telescope) and GAIA (Global Astrometric Interferometer for Astrophysics) spacecraft in China. European Space AgencyTo study 247,104 asteroids ranging in age from 15 billion to 13.8 billion years.
The results, combined with future studies using the same technique, could help astronomers better understand how galaxies formed, how our galaxy formed, and how we came here to think about any of these questions.
“With an innovative approach to estimating the birth dates of stars, Chiang and Ricks were able to help us better understand how our galaxy formed,” wrote Timothy Pierce, a physicist at the University of Notre Dame. Natural On Wednesday.
“And this approach is scalable, which means that when data is available for larger samples of stars in the Milky Way, the picture will be even sharper.”
