Andromeda Galaxy is the closest large galaxy to Milky Way galaxy , and contains stars several times the Milky Way galaxy. Now, an international team of scientists has figured out how she reached such a huge size.
Andromeda galaxy is beautiful, but this beauty is sinister.
Several years ago, researchers led by astrophysicists from the University of Sydney (Australia) discovered the mysterious globular cluster on the periphery of the Andromeda galaxy. Andromeda galaxy is the large galaxy closest to us, 800 kiloseconds away from the Milky Way, forming a stream they call the "Delice structure" (translated from the Welsh language dulaish - "Black Stream", the same name is the rivers and valleys of Wales).
Now they found that these clusters are actually traces of the violent movement of Andromeda galaxies in the past, which scales up by swallowing smaller galaxies. Scientists have identified at least two traces of “feasts”: one occurred relatively recently, and in the past 5 billion years, the second happened much earlier, about eight to ten billion years ago, shortly after our universe formed.
Astronomers are interested in the development of Andromeda galaxy because it is very similar to the Milky Way, but, alas, it is not very convenient to observe our Milky Way from Earth. But we can observe other galaxies freely because they are not obscured by the stars and nebula closest to us.
If the growth pattern of Andromeda galaxy is typical of large spiral galaxies, it is very likely that the past Milky Way has swallowed smaller galaxies and its volume has increased dramatically afterwards. However, our galaxy may have a different development model that does not include absorption of similar types: its growth, for example, is due to the "peaceful" contraction of interstellar matter.
So far, researchers can only determine the velocity of motion and chemical composition of globular clusters: they have proven to have significantly lower metal content than surrounding stars. In the future, astronomers will estimate the distance between various structures and build three-dimensional models of flowing, literally the past of Andromeda galaxy during its cruel "feast."
This study can be obtained on the arXiv preprint server and will be published in the Monthly magazine of the Royal Astronomical Society .
