Chandra Release - November 23, 2015

Visual Description: SDSS J103842.59+484917.7

The image is an X-ray and optical image of a group of galaxies called SDSS J103842.59+484917.7, also known as the Cheshire Cat.  The dominant colors in the image are purple and black with pops of pale gold.  The structure of the Cheshire Cat resembles a smiling face, which can be seen in the center of the image.    The Cheshire Cat's appearance is due to gravitational lensing, where the mass of the galaxy cluster bends and distorts light passing through it, creating an optical illusion of a smiling face.  Specifically, the mass that distorts the faraway galactic light is found surrounding the two giant "eye" galaxies and a "nose" galaxy. The multiple arcs of the circular "face" arise from gravitational lensing of four different background galaxies well behind the "eye" galaxies. The individual galaxies of the system, as well as the gravitationally lensed arcs, are seen in optical light from NASA's Hubble Space Telescope.  Each "eye" galaxy is the brightest member of its own group of galaxies and these two groups are racing toward one another at over 300,000 miles per hour. Data from NASA's Chandra X-ray Observatory (purple) show hot gas that has been heated to millions of degrees, which is evidence that the galaxy groups are slamming into one another. Chandra's X-ray data also reveal that the left "eye" of the Cheshire Cat group contains an actively feeding supermassive black hole at the center of the galaxy.