The Milky Way is a massive and large spiral galaxy that is unique in its cosmic neighborhood. Scientists are still unsure why our home galaxy is such a special case. In 2014, astronomers discovered that the Milky Way is part of larger structures and belongs to the Local Group, which is surrounded by a ring of twelve large galaxies known as the Council of Giants. The astronomy community also knows that all galaxies and superclusters in our cosmic neighborhood together form the Local Plane.
Miguel Aragón from the National Autonomous University of Mexico (UNAM) explains that this filament, consisting of dark matter and galaxies, runs through cosmic voids in its environment as a kind of cosmological wall. The scientific community is investigating whether the galaxy’s membership in such a wall affects its development. Studies have shown that the gravity of other objects in such a structure affects growth and movement.
The team led by Aragón used the IllustrisTNG simulation, the most comprehensive and high-resolution simulation of galaxy development, to analyze whether this also applies to the Milky Way. According to their publication in the Monthly Notices of the Royal Astronomical Society, the astronomers reconstructed galaxy formation in an area of the universe nearly one billion light-years in size, containing millions of galaxies. The simulation showed that the Milky Way is a cosmic anomaly, with only a small percentage of galaxies as large as it is and part of a local galaxy wall.
The study shows that our home galaxy is too heavy and large for its cosmic environment. This feature is significant enough to consider the Milky Way as something truly special. However, scientists are still unsure why the galaxy has reached this unusual size, although they believe that the many collisions in its development history could be responsible. The study highlights the importance of understanding the development of galaxies and their place in the universe.
