The age map covers a vast area of the sky, encompassing two-thirds of the Milky Way disk and including both the inner and outer regions. By analyzing the light from millions of stars, the team was able to estimate their ages and trace the evolution of the galaxy.
The map shows that the Milky Way formed in a series of distinct stages, with different regions forming at different times. The oldest stars in the galaxy are found in the inner regions, near the center, while the younger stars are located in the outer regions.
This finding is consistent with the current understanding of how galaxies form and evolve. Galaxies are thought to start as small clouds of gas that gradually collapse under their own gravity, forming stars. As the galaxy grows, new stars continue to form, with the youngest stars located at the galaxy's outermost edges.
The age map also reveals evidence of several mergers and interactions with neighboring galaxies. The researchers identified several streams of stars that appear to have been pulled from smaller galaxies that collided with the Milky Way over time. These mergers played a significant role in shaping the Milky Way's structure and evolution.
The new age map provides astronomers with a valuable tool for understanding the complex history of the Milky Way galaxy. It will help researchers study topics such as the formation and evolution of galaxies, the origin of the elements, and the distribution of dark matter in the universe.
The age map is based on data from the European Space Agency's Gaia satellite, which has been mapping the positions, distances, and motions of stars in the Milky Way. Gaia's vast dataset allowed the team to construct the most detailed age map of the galaxy to date.
The research was published in a series of papers in the journals Astronomy & Astrophysics and The Astrophysical Journal. The lead authors of the papers are:
- Dr. Eline Tolstoy, Max Planck Institute for Astronomy
- Dr. Giovanni Battaglia, University of California, Berkeley
- Dr. Ricardo Schiavon, Liverpool John Moores University
The research team includes astronomers from the Max Planck Institute for Astronomy, the University of California, Berkeley, Liverpool John Moores University, the Institute of Astrophysics and Space Sciences, and the University of Barcelona.
