Chandra Release - August 14, 2013

Visual Description: NGC 1232

An X-ray and optical image of the galaxy NGC 1232 showcases a collision between two galaxies. The dominant colors in this image are blue-purple and pink. The galaxy is shaped like a spiral, with its arms stretching outwards from the center, on a black background. In the X-ray view, the galaxy's central region is brighter and more concentrated, while the outer regions appear fainter and more diffuse. The X-ray emission (pink) from NASA’s Chandra X-ray Observatory is shaped like a large soft comet and reveals a massive cloud of multimillion-degree gas.  The hot gas cloud is likely caused by a collision between a dwarf galaxy and the much larger galaxy NGC 1232.  The impact between the dwarf galaxy and the spiral galaxy caused a shock wave -- akin to a sonic boom on Earth -- that generated hot gas with a temperature of about 6 million degrees. Optical data from the Very Large Telescope reveal the spiral galaxy in blue and white. X-ray point sources have been removed from this image to emphasize the diffuse emission. Near the head of the comet-shaped X-ray emission is a region containing several very optically bright stars and enhanced X-ray emission. Star formation may have been triggered by the shock wave, producing bright, massive stars.