Credit: NASA/JPL-Caltech/S.A. Stanford (UC Davis/LLNL)

Great Galactic Buddies

Like great friends, galaxies stick together. Astronomers using NASA's Spitzer Space Telescope have spotted a handful of great galactic pals bonding back when the universe was a mere 4.6 billion years old. The universe is believed to be 13.7 billion years old.

Collectively, these great galactic buddies are called galaxy clusters. A typical galaxy cluster can contain hundreds of galaxies and trillions of stars.

In this false-color composite, some of the oldest galaxy clusters in the universe pose for Spitzer's Infrared Array Camera. The individual galaxies that make up the distant clusters are shown as red dots in all four images.

The green blobs are Milky Way stars along the line of sight, and the blue specks are faint galaxies at various distances along the line of sight. The green and blue data are from a visible-light, ground-based telescope.

The cluster at 9.1 billion light-years away (lower right panel) is currently the most distant galaxy cluster ever detected.

These images are three-color composites, in which blue represents visible light with a wavelength of 0.4 microns, and green indicates visible light of 0.8 microns. The visible data were captured by the ground-based Mosaic-1 camera at the Kitt Peak National Observatory in Tucson, Ariz. Red represents infrared light of 4.5 microns, captured by Spitzer's infrared array camera.

About the Object	Object Name: ISCS J143809+341419 Object Type: Galaxy Cluster (Most Distant Yet Detected) Position (J2000): RA: 14:38:09 Dec: +34:14:19 Distance: 9.1 billion light-years
About the Data	Image Credit: NASA/JPL-Caltech/S.A. Stanford (UC Davis/LLNL) Instrument: Mosaic-I camera on KPNO Mayall 4-m telescope, IRAC on Spitzer Space Telescope Wavelength: 0.4 (blue), 0.8 (green), and 4.5 (red) microns Exposure Date: IRAC: January 10 - 14, 2004; Mosaic: April 2000 - April 2004 Exposure Time: IRAC: 90 seconds, Mosaic-I: 1 - 2 hours (blue), 2 - 4 hours (green) Release Date: 21 March 2006
Observers	Peter Eisenhardt, (JPL/Caltech) Mark Brodwin, (JPL/Caltech) Michael Brown (Princeton) Arjun Dey (NOAO) Anthony Gonzalez, (U Florida) Buell Jannuzi (NOAO) Adam Stanford, (UC Davis and IGPP/LLNL) Daniel Stern (JPL/Caltech)

Individual Images

	8.15 billion light-years Screen-Resolution (450x450): JPEG High-Resolution (1629x1629): JPEG | Mac TIFF | PC TIFF Credit: NASA/JPL-Caltech/S.A. Stanford (UC Davis/LLNL)
	8.59 billion light-years Screen-Resolution (435x450): JPEG High-Resolution (1548x1600): JPEG | Mac TIFF | PC TIFF Credit: NASA/JPL-Caltech/S.A. Stanford (UC Davis/LLNL)
	8.98 billion light-years Screen-Resolution (431x450): JPEG High-Resolution (1108x1158): JPEG | Mac TIFF | PC TIFF Credit: NASA/JPL-Caltech/S.A. Stanford (UC Davis/LLNL)
	9.09 billion light-years Screen-Resolution (450x450): JPEG High-Resolution (1167x1167): JPEG | Mac TIFF | PC TIFF Credit: NASA/JPL-Caltech/S.A. Stanford (UC Davis/LLNL)

The Spitzer Space Telescope is a NASA mission managed by the Jet Propulsion Laboratory. This website is maintained by the Spitzer Science Center, located on the campus of the California Institute of Technology and part of NASA's Infrared Processing and Analysis Center.