Hubble is out with a new image just in time for Halloween. The blue glows in the image below show the remnants of once vibrant galaxies.
These ghostly glows are all that’s left of galaxies ripped apart more than 4 billion years ago. These galaxies are located about 4 billion light-years away in an area called “Pandora’s Cluster,” known scientifically by its less appealing name – Abell 2744.
The galaxies that are not glowing blue are actually located in either the foreground or background, and are not part of the cluster.
Hubble astronomers believe up to six galaxies were torn to shreds inside Pandora’s Cluster over a period of about 6 billion years.
The latest image from the Hubble confirms a hypothesis that light from these dead galaxies should be detectable.
“The Hubble data revealing the ghost light are important steps forward in understanding the evolution of galaxy clusters,” said Ignacio Trujillo of the Instituto de Astrofísica de Canarias (IAC), La Laguna, Tenerife, Spain, one of the researchers involved in this study of Abell 2744.
“It is also amazingly beautiful in that we found the telltale glow by utilizing Hubble’s unique capabilities.”
“The results are in good agreement with what has been predicted to happen inside massive galaxy clusters,” added Mireia Montes of the IAC.
Why the interest in Abell 2744? This cluster was actually picked as part of the Frontier Fields program. It’s a three-year plan by Hubble and NASA’s other observatories to use certain massive galaxy clusters as a super zoom lens to look into the more remote regions of the universe.
The gravitational forces in these clusters are so great that gravity deflects light passing through them, creating an effect known as gravitational lensing. Astronomers use this effect to observe galaxies they would otherwise not be able to see.
While other astronomers were busy taking advantage of gravitational lensing, Montes’ team was studying the environment of the foreground cluster (the cluster used for gravitational lensing). They plan to look for the same ghostly glows in the five other clusters that are part of the Frontier Fields program.