In the new study, a group of scientists has analyzed this question in detail.
In this study, researchers show that in elliptical galaxies only 40 percent of free gas falls to the central region. This gas, stimulating star formation processes, characterized by a low angular moment. The researchers explain this difference between the values of angular momentum in galaxies of different types with the differences in the formation of galaxies.
Most of the stars in elliptical galaxies formed as a result of the rapid collapse , at which the scattering of angular momentum takes place. This process is likely to finish very early in the history of the galaxy, provoked by supernova explosions. In the case of spiral galaxies gas falls slowly, while maintaining its angular momentum and the stars are formed slowly too during almost the entire history of the galaxy.
“Until recently, the current paradigm of the formation and evolution of galaxies assumed that elliptical galaxies are formed by the merger of the galactic disk in a distant part of the universe. From this point of view, their low angular momentum probably was due to dissipative processes occurring in such mergers” , – noted researchers.