Hubble Space Telescope Solves the Mystery of Dead Galaxies

Recent scientists conducted studies on early galaxies which brought a lot of attention earlier this year. They discovered six massive galaxies that seem to have died during the universe’s most active period of star birth. NASA’s Hubble Space Telescope spied the six galaxies, which appeared to have run out of the cold hydrogen gas needed to make stars while most other galaxies were producing new stars at a rapid pace.

Kate Whitaker, a University of Massachusetts, Amherst assistant professor of astronomy and lead author of a recent study on the six galaxies said that at this point in our universe, all galaxies should be forming lots of stars. The lead author said that it is the peak epoch of star formation.

Without the cold hydrogen gas necessary to fuel stars and birth new ones, the galaxies are essentially dead. They’re also unable to rejuvenate, even if they have absorbed nearby smaller galaxies and gas clouds. Whitaker said that the act of absorbing just “puffs up” the dead galaxies. Whitaker added that these are some of the open questions that we’ll continue to explore with new observations down the road.

Hubble Space Telescope was used by the astronomers to pinpoint the galaxies, and then, using the Atacama Large Millimeter/submillimeter Array (ALMA) in northern Chile, the researchers were able to detect whether or not the galaxies contained the cold dust that signals the existence of cold hydrogen gas. According to NASA, the distant galaxies are behind a cluster, they appear stretched and magnified in the images. That help astronomers see details that would otherwise be lost without the magnification from the galaxy clusters.