Unraveling the Enigma: Decoding the Milky Way's Mysterious Spiral Structure

Astronomers have long wondered why spiral galaxies like the Milky Way are scarce in our region of the universe, which is dominated by elliptical galaxies. A new supercomputer simulation suggests that frequent interactions among galaxies in the supergalactic plane smooth out potential spiral arms, leading to the formation of elliptical galaxies. When two galaxies of comparable mass are near each other, the ordered motions of stars become disordered, removing the appearance of spiral arms. Large galaxy mergers can also randomize star orbits and trigger starbursts, reducing the amount of new stars that can be formed. The study suggests that once a galaxy becomes elliptical, it is unlikely to return to its original spiral shape.