A team of astronomers from the Center for Astrophysics. Harvard and the Smithsonian have started a new field called “extragalactic archaeology”.
According to the new study published in the journal nature astronomyScientists have found a way to reconstruct the evolution and timeline of distant galaxies. Previously the “extragalactic archaeology” method was used only for the Milky Way Galaxy.
By studying the chemical “fingerprints”, particularly oxygen patterns, of the distant spiral galaxy NGC 1365, researchers were able to reconstruct its 12 billion-year history.
“This is the first time that the chemical archeology method has been used with such fine detail outside our own galaxy,” says Lisa Cawley, lead author, Harvard professor and director of the Center for Astrophysics.
By comparing real-world observations from the Typhoon survey with 20,000 computer simulations from the Illustris project, the team found that NGC 1365 evolved from a small cluster into a giant spiral through continuous mergers with smaller dwarf galaxies.
Key findings also include:
- The central region formed very early in cosmic history.
- The Milky Way grew over 12 billion years by “consuming” smaller dwarf galaxies.
- The outer spiral arms are relatively young, having formed only in the last few billion years.
- Oxygen patterns are shaped by star formation, supernova explosions, gas flows, and galactic mergers.
According to astronomer Lars Hernqvist, CFA and Mallinckrodt Professor of Astrophysics at Harvard, “This study shows that the astronomical processes we model on computers are shaping galaxies like NGC 1365 over billions of years.”
This new field of “extragalactic archaeology” provides a new blueprint for understanding how galaxies, including our own Milky Way, formed and evolved over cosmic time.
This success will allow scientists to compare our galaxy with other distant galaxies to determine its evolution.
