Chandra Release - January 4, 2010

Visual Description: NGC 1399

An image of an elliptical galaxy, NGC 1399, is the main subject of this astronomical image. The galaxy is colored in dim burnished gold and bright blue and is surrounded by many small dots of light, with larger dots in blue and tiny faint dots in dark gold. Evidence from NASA's Chandra X-ray Observatory and the Magellan telescopes suggest a star has been torn apart by an intermediate-mass black hole in a globular cluster.  The source is positioned at 11 o’clock in the image. X-rays from Chandra are colored in blue and are overlaid on an optical image from the Hubble Space Telescope in gold. Chandra observations show that this object is a so-called ultraluminous X-ray source (ULX). An unusual class of objects, ULXs emit more X-rays than any known stellar X-ray source, but less than the bright X-ray sources associated with supermassive black holes in the centers of galaxies. Their exact nature has remained a mystery, but one suggestion is that some ULXs are black holes with masses between about a hundred and a thousand times that of the Sun.