Galactic archeology reveals Andromeda’s dramatic history. Galaxy formation was more intense than that of the Milky Way, with several episodes of intense star formation due to intergalactic collisions. A study by scientists at the University of Hertfordshire has revealed the dramatic history of Andromeda, our nearest neighboring galaxy. An international team of astrophysicists has determined details of the galaxy’s history using galactic archeology, a method of studying the chemical composition of stars and the evolution of the galaxy. their host to reconstruct its past.

Scientists examined Andromeda’s elemental composition as well as the gas and dust content of the planetary nebula, which is formed from the abandoned outer layers of dying low-mass stars.

Analysis shows that Andromeda’s formation was more dramatic and powerful than the formation of our Galaxy. After the violent burst of star formation at the time of galaxy formation, between 2 and 4.5 billion years ago, another explosion occurred, most likely caused by a so-called “wet merger.” – the merger of two gas-rich galaxies. causing a violent burst of star formation. star formation. Scientists, based on the positions and movements of individual stars in the galaxy, have long assumed that Andromeda formed from the merger of two galaxies.

Astrophysics Professor Kobayashi, from the University of Hertfordshire’s Center for Astrophysics Research, said: “This is a great example of how galactic archeology can provide new insights into the history of space history. By analyzing the chemical enrichment of different generations of Andromeda stars, we can revive its history and better understand its origins. » Professor Kobayashi’s theoretical model predicts two different compositions of stars in the two components of Andromeda’s disk. One preparation contains ten times more oxygen than iron, and the other preparation contains approximately equal amounts of oxygen and iron.

source: https://arxiv.org/abs/2309.01707