Andromeda Galaxy - Composite X-Ray / Optical / Infrared Image

This composite image of M31 (Andromeda) shows Chandra X-ray data in gold, optical data from the Digitized Sky Survey in light blue and infrared data from the Spitzer Space Telescope in red. A zoom into the central region of M31 dissolves into the Chandra field of view. Scientists have calculated that the Chandra image would be about 40 times brighter than observed if Type Ia supernova in the bulge of this galaxy were triggered by accretion of material from a normal star onto a white dwarf star. This implies that the merger of two white dwarfs is the main trigger for Type Ia supernovas in this galaxy. credit: X-ray (NASA/CXC/MPA/M.Gilfanov & A.Bogdan), Infrared (NASA/JPL-Caltech/SSC), Optical (DSS) source: http://chandra.harvard.edu/photo/2010/type1a/animations.html