NASA's Spitzer Space Telescope's sensitive infrared detectors map out faint regions of new star formation in this pair of colliding galaxies known as Arp 107. Like a beautiful pearl necklace, young star clusters have formed along the ring-like tidal arm in this system. Spitzer images at 8 microns (second picture above) provide a clear view of these clumps of young stars. In contrast, in the shorter wavelength 3.6 micron band (first picture), the older stars in the small companion to the northeast and the bridge connecting the two galaxies are bright. The color-coded multi-band picture (third picture; red=8.0 microns, blue=3.6 microns) emphasizes this difference in stellar ages.

North is up and east is to the left on these images. The field of view is 3 arcminutes.

These Spitzer images were presented at the American Astronomical Society meeting in Minneapolis, Minnesota, on May 30, 2005. A journal article with a detailed analysis of these maps has been submitted to the Astronomical Journal.

see http://gallery.spitzer.caltech.edu/Imagegallery/image.php?image_name=sig05-006 High quality tif files also avaliable.

	This file is in the public domain in the United States because it was solely created by NASA. NASA copyright policy states that "NASA material is not protected by copyright unless noted". (See Template:PD-USGov, NASA copyright policy page or JPL Image Use Policy.)
	Warnings: Use of NASA logos, insignia and emblems is restricted per U.S. law 14 CFR 1221. The NASA website hosts a large number of images from the Soviet/Russian space agency, and other non-American space agencies. These are not necessarily in the public domain. Materials based on Hubble Space Telescope data may be copyrighted if they are not explicitly produced by the STScI.[1] See also {{PD-Hubble}} and {{Cc-Hubble}}. The SOHO (ESA & NASA) joint project implies that all materials created by its probe are copyrighted and require permission for commercial non-educational use. [2] Images featured on the Astronomy Picture of the Day (APOD) web site may be copyrighted. [3] The National Space Science Data Center (NSSDC) site has been known to host copyrighted content. Its photo gallery FAQ states that all of the images in the photo gallery are in the public domain "Unless otherwise noted."