Galactic Archaeology Unveils NGC 1365

Astronomers have pioneered "galactic archaeology" to map the chemical "fossil record" of a galaxy beyond the Milky Way for the first time, reconstructing 12 billion years of its evolution through chemical fingerprints. This groundbreaking method, applied to the giant spiral galaxy NGC 1365, revealed its growth through repeated mergers with smaller dwarf galaxies, establishing a powerful new tool for understanding galactic development.

Astronomers have pioneered "galactic archaeology" to map the chemical "fossil record" of a galaxy beyond the Milky Way for the first time, as reported by EurekAlert!. This new method reconstructs the evolution of distant galaxies by analyzing chemical fingerprints in deep space.
The study, detailed in Nature Astronomy, focused on NGC 1365, a giant spiral galaxy, revealing its growth over 12 billion years through mergers with smaller dwarf galaxies. According to SciTechDaily, this research establishes "extragalactic archaeology" as a powerful new tool in astronomy.
Carnegie Science noted that the breakthrough was made possible by data from the Carnegie-led TYPHOON survey, which provided extraordinarily sharp resolution to study individual star-forming clouds in NGC 1365. This allowed researchers to create a "3D photocopy" of the galaxy rich in spatial and chemical information.
By tracing oxygen patterns across NGC 1365 and comparing them with state-of-the-art galaxy simulations, astronomers reconstructed its history, finding that its central region formed early and became oxygen-rich. As Discover Magazine explained, the outer regions developed over billions of years through repeated collisions with smaller dwarf galaxies.
Lead author Lisa Kewley, from the Center for Astrophysics | Harvard and Smithsonian, emphasized the significance of this work, stating, "This is the first time that a chemical archaeology method has been used with such fine detail outside our own galaxy," as quoted by The Debrief. This approach aims to understand how galaxies, including our own Milky Way, formed and evolved.
IFLScience highlighted that this technique allows scientists to see how dwarf galaxies merged and influenced the subsequent evolution of larger galaxies, providing incredible insights into galactic development.