Galaxies, the colossal cosmic entities that populate the universe, are not static islands of stars. They are dynamic systems, constantly interacting and evolving. One of the most dramatic aspects of this evolution is galactic cannibalism, where larger galaxies “feast” on smaller ones, merging and transforming in spectacular displays of cosmic power.
Recently, NASA released a mesmerizing visualization of this process, generated by the Pleiades supercomputer at NASA’s Ames Research Center. This simulation, based on observations of galaxies and the gases surrounding them, offers an unprecedented view of the dynamic interplay between galaxies and the intergalactic medium.
The simulation reveals how galaxies feed on gases strewn across the vast spaces that separate them. These gases, expelled from stars as supernovae, are drawn back into galaxies, fueling the formation of new stars. The visualization uses color to represent the density and temperature of the gases, with yellow indicating high-density regions and purples showing sparser areas. Bursts of red highlight the energetic supernovae explosions that create superwinds, blowing gas into intergalactic space.
This constant cycle of gas expulsion and accretion is a key driver of galactic evolution. In the early life of a galaxy, this process is particularly turbulent. As galaxies mature, they tend to calm down, though collisions between galaxies can disrupt this quiescence. Our own Milky Way is destined for such a collision with the Andromeda galaxy in about five billion years.
Supercomputer simulations like this are crucial for understanding the complex processes that shape galaxies. Because the gas between galaxies emits little light, it’s difficult to observe directly. Supercomputers help fill in the gaps, providing stunning visualizations of the epic cycle of star death and rebirth that drives galactic evolution.
