Frontier Field Day

Recently, NASA has begun a new experiment known as “Frontier Fields,” in which they use three space telescopes--the Hubble, Spitzer and Chandra--to observe six large galaxy clusters over the next three years. The image below shows one of these large galaxy clusters known as Abell 2744.

By peering out toward these clusters, which contain hundreds of galaxies, scientist can see farther into the universe than ever before. This is thanks to a concept known as a “gravitational lens.” However, before we continue any further, what exactly is a gravitation lens? First off, understand that gravity curves both space and time, so the larger the mass of an object, the more one can see this bending of light occur. A gravitational lens is a phenomenon that is seen in space with large-mass objects. The larger the mass of an object, the greater its gravity will be. Understanding now that gravity bends space and time, if we view a large enough object (such as a galaxy cluster), the light athwart the initial object is then bent around, becoming not only visible, but magnified as well, as if it were a lens. The image below is a visual depiction of gravitational lensing.

Now that we have a better understanding of what gravitational lensing is, how is this being used for the “Frontier Fields” experiment? Released as the first view of the “Frontier Fields,” the image above marks the deepest observations of a galaxy cluster. The photo is of Abell 2744, a galaxy cluster found some 3.5 billion light-years away. Due to its mass, scientist can view galaxies another 8.5 billion light-years beyond the cluster (12 billion light-years from Earth), due to its intense gravitational lens. Not only are these distant galaxies visible, but magnified as well, giving scientist a more in-depth view of deep space. Some of these background galaxies are 10 to 20 times larger than they would normally appear, due to lensing. Of these background galaxies the faintest are intrinsically 10 to 20 times dimmer than any galaxy seen before. Astronomers are quite intrigued by these fainter galaxies and want a better understanding as too what these faint objects truly are. Of the objects spotted in the image were dwarf galaxies, some one-thousandth the size of our galaxy which many were missed in previous observations of the cluster, and some galaxies 100 times the size of our own.

Another benefit to this project is the capability to map dark matter. What is dark matter? Essentially, dark matter is a mysterious substance thought to make up the bulk of the mass in the universe. The way scientists expect to map such a substance will be to view these detailed images and look into the way dark matter distorts background light.

"The Frontier Fields is combining the power of nature's telescopes — these massive clusters of galaxies — with Hubble to provide the intrinsically deepest yet view of the universe," Jennifer Lotz, a principal investigator with the Space Telescope Science Institute in Baltimore said during a press conference. The combined work of all three space telescopes is expected to yield a better understanding and probe deeper into the origins, as well as the evolution of galaxies and black holes across the universe. Through the joint efforts of these three telescopes, scientists have an ambitious goal to use galaxy clusters to explore the first billion years of the universe’s history.

Blog written by Gregg McCambley – AccuWeather Deep Space Expert

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