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Distant Galaxy Cluster Infrared Survey Poster
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Bird's Eye View Mosaic | Bird's Eye View Mosaic with Clusters |
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9.1 Billion Light-Years |
8.7 Billion Light-Years |
8.6 Billion Light-Years |
Astronomers have discovered nearly 300 galaxy clusters and groups,
including almost 100 located 8 to 10 billion light-years away, using the
space-based Spitzer Space Telescope and the ground-based Mayall 4-meter
telescope at Kitt Peak National Observatory in Tucson, Ariz. The new
sample represents a six-fold increase in the number of known galaxy
clusters and groups at such extreme distances, and will allow astronomers
to systematically study massive galaxies two-thirds of the way back to the
Big Bang.
A mosaic portraying a bird's eye view of the field in which the distant
clusters were found is shown at upper left. It spans a region of sky 40
times larger than that covered by the full moon as seen from Earth.
Thousands of individual images from Spitzer's infrared array camera
instrument were stitched together to create this mosaic. The distant
clusters are marked with orange dots.
Close-up images of three of the distant galaxy clusters are shown in the
adjoining panels. The clusters appear as a concentration of red dots near
the center of each image. These images reveal the galaxies as they were
over 8 billion years ago, since that's how long their light took to reach
Earth and Spitzer's infrared eyes.
These pictures are false-color composites, combining ground-based optical
images captured by the Mosaic-I camera on the Mayall 4-meter telescope at
Kitt Peak, with infrared pictures taken by Spitzer's infrared array
camera. Blue and green represent visible light at wavelengths of 0.4
microns and 0.8 microns, respectively, while red indicates infrared light
at 4.5 microns.
Kitt Peak National Observatory is part of the National Optical Astronomy
Observatory in Tuscon, Ariz.