G266.2-1.2 was produced by the explosion of a massive star in the Milky Way galaxy. A Chandra observation of this supernova remnant reveals the presence of extremely high-energy particles produced as the shock wave from this explosion expands into interstellar space. In this image, the X-rays from Chandra (purple) have been combined with optical data from the Digitized Sky Survey (red, green, and blue).
Image Credit: X-ray: NASA/CXC/Morehead State Univ/T.Pannuti et al, Optical: DSS
Explanation from: https://www.nasa.gov/mission_pages/chandra/multimedia/supernova-remnant-g266.html