Computer simulations show that powerful streams of gas can leave one galaxy, travel across space, and get absorbed into another.
Even though there’s no air blowing around in space, the cosmos can be a pretty windy place.
Winds made of gas particles whip around galaxies at high speeds, measuring hundreds of kilometers per second. Astronomers suspect they’re created by supernovae, when nearby stars explode and send streams of photons powerful enough to push around gas. This wind can be ejected out of galaxies into intergalactic space. Some of the wind will keep traveling into the void, while a fraction will get sucked back in—a process known as wind recycling.
While astronomers have known for decades that galactic winds exist, they’re still trying to determine precisely what triggers and drives them. Daniel Anglés-Alcázar, an astrophysicist at Northwestern University in Illinois, and his colleagues recently decided to study the process behind wind recycling. They plugged a bunch of data into computer simulations of galaxy formations, ready to compare their results with previous models.