Chandra Release - January 6, 2009

Visual Description: Cassiopeia A

This is a frame from an artist’s translation of data of a supernova remnant called Cassiopeia A. The image shows a bright blue-white neutron star in the center, surrounded by a colorful, swirling gas cloud.  This visualization is based on X-ray data from Chandra, infrared data from Spitzer and optical data from NOAO's 4-meter telescope at Kitt Peak and the Michigan-Dartmouth-MIT 2.4-meter telescope. The colors present in the image are various shades of purple, pink, green, blue and red.  The green clump is towards the lower left, with red more towards the center, blue towards the perimeter, and yellow in jets streaking out at 11 and 3 o’clock.  The structure of Cassiopeia A can be described as a large, irregularly shaped gaseous nebula. In the visualization, the green region is mostly iron observed in X-rays. The yellow region is a combination of argon and silicon seen in X-rays, optical, and infrared - including jets of silicon - plus outer debris seen in the optical. The red region is cold debris seen in the infrared. Finally, the blue reveals the outer blast wave, most prominently detected in X-rays.  Most of the material shown in this visualization, which begins with an artist's rendition of the neutron star previously detected by Chandra, is debris from the explosion that has been heated by a shock moving inwards. The red material interior to the yellow/orange ring has not yet encountered the inward moving shock and so has not yet been heated. These unshocked debris were known to exist because they absorb background radio light, but they were only recently discovered in infrared emission with Spitzer. The blue region is composed of gas surrounding the explosion that was heated when it was struck by the outgoing blast wave.