Through the Magnifying Glass

Hubble Uses Lensing Galaxies as Distant Universe Probe

Look at THAT picture!  Enlarge it! I LOVE images like this.

So, what are we looking at?  This is Abell 2744 (as seen by Hubble Space Telescope) which is also known as Pandora’s Cluster. It’s a cluster of galaxies that formed when four separate galaxy clusters smashed together to form a massive one.  It’s a mix of all sorts of galaxies. You can, without trying too hard, find ellipticals, spirals, edge-on galaxies, and others.

The combined gravitational pull of all those galaxies in the cluster provides a lens through which astronomers can view (albeit distorted) very distant early galaxies. The gravitational lensing is a powerful tool to explore some of the most faraway galaxies and galaxy-objects in the universe.  It  essentially deflects and “bends” light from distant objects behind the cluster, which smears the appearance of the galaxies into arcs, and creating bizarre multiple-image apparitions.

As well as creating these weird shapes, lensing also magnifies the images so that astronomers can see more detail in the distant galaxies. This means that objects that otherwise would be incredibly difficult or impossible to see are made visible.

This tendency to reveal hidden galaxies is an artifact of gravitational lensing that a program called Frontier Fields will explore over the next few years. So, we could see a great many more objects like this one splash across the Web pages of the Hubble Space Telescope. And, for good reason: we’re getting a few of the distant universe that until gravitational lensing was discovered and incorporated into viewing plans, was nearly impossible. So, check out the Hubble pages once in a while. You just might find yourself staring at the distant universe through a gravitational lens of galaxies.