Just looking back on old images
A Galactic Cloud of Antimatter May 1, 1997
http://antwrp.gsfc.nasa.gov/apod/ap970501.html
Somehow I must have missed this image.
It looks fantastic.
The center of our Milky Way Galaxy is full of surprises. Its latest spectacular is a mysterious cloud glowing in gamma rays produced by annihilating antimatter particles! Star Trek fans are all too familiar with the consequences of mixing matter (electrons) and antimatter (positrons) - the particles catastrophically annihilate converting their masses to energy according to Einstein's famous E=mc2. Positron/electron annihilation energy is emitted as gamma rays with photon energies of 511,000 electron volts