A recent study suggests that there may have been more than one galactic core in the Milky Way’s history, which spans over 13 billion years. The study, which was published in The Astrophysical Journal, highlights the Milky Way’s 12.5 billion-year-old primordial core.
Although this core has been noted in prior studies, this is the first time that it has been outlined and fleshed out in such detail. The researchers were able to tie everything together so nicely due to the metallicity of the stars, which essentially refers to the chemical compositions and motions that the stars have in common.
The study of the Milky Way’s core provides valuable insights into the evolution of our galaxy and the processes that have shaped it over time. By understanding the history of the galactic core, scientists can better understand the origins of the Milky Way and our place within it.
The researchers were able to determine which stars are more tightly bound together by analyzing their chemical compositions and motions, which gave them a good overview of the ancient Milky Way’s core. However, because stars eventually reach the limit of their ability to fuse atomic nuclei and die, it makes sense for the core of our galaxy to have changed over time.
The study of the Milky Way’s core and its evolution over time is an ongoing area of research, with new findings regularly emerging. By studying the core of the Milky Way, scientists can gain a deeper understanding of the processes that have shaped our galaxy and the universe as a whole. This research is crucial for advancing our understanding of the origins and evolution of the cosmos.
Image source: udoikel09 / AdoƄe
The ancient Milky Way core was easy to outline because the earliest stars were mainly made up of hydrogen and helium, and did not contain the many metals that later stars contained. When a group of stars with similar metallicity is found, it makes sense to conclude that they are from a similar population or formation.
Using the ESA’s Gaia space observatory, researchers identified more than two million stars in the relevant area of the galaxy whose metallicity suggests they were present before the Milky Way’s edge expanded and it became filled with stars. The researchers began to refer to the ancient core of the Milky Way as the “poor old heart” of the galaxy because the stars in this region are metal-poor and very old.
The study of the Milky Way’s ancient core and its population of metal-poor, old stars provides valuable insights into the early history and evolution of our galaxy. By understanding the formation and development of the Milky Way’s core, scientists can gain a better understanding of the origins and evolution of the universe as a whole
A map of мetal-poor red giant stars in the galactic center. (H.-W. Rix/MPIA)
The metal-poor, old stars that make up the ancient core of the Milky Way are also coincidentally found in the heart of our galaxy. This has led scientists to suggest that these stars may be remnants of proto-galaxies from our galaxy’s infancy. These “seeds” or stars were not full-fledged galaxies themselves, but instead the building blocks that would later clump together to form our Milky Way galaxy. As galaxies merged together over time, the Milky Way grew even larger.
Studying the ancient core of the Milky Way and its population of metal-poor, old stars provides valuable insights into the formation and evolution of our galaxy. By understanding the processes that have shaped the Milky Way over time, scientists can gain a better understanding of the origins and evolution of the universe as a whole.
Source: sciencealert.coм
