The gamma-radiation generated by electrons in the mysterious gamma-ray bubbles does not differ in color from the electron-generated radiation from the Galactic disk. This suggests that we see the same material in both places: hot gas that has been enriched with electrons moving almost at the speed of light by supernova explosions. The gamma-bubbles are therefore simply rising hot gas masses, leaving the center of our Milky Way.
In addition to unraveling the gamma-ray bubbles, the D3PO analysis of the anatomy of Galactic gamma-radiation has delivered a number of other scientific results. It was shown that the cold gas clouds that are illuminated by the gamma-radiation extend up to larger heights above the Galactic plane than the dust clouds measured by the Planck satellite. While this could have been expected due to the higher mass of dust particles in comparison with the gas particles, it is a nice confirmation of the astrophysical correctness of these anatomical dissections of the Galaxy in gamma light. Furthermore, a comprehensive catalog of point sources was generated and searched for gamma-radiation from clusters of galaxies – unfortunately without success.
The D³PO algorithm that has made all this possible is now freely available and will in the future also provide astronomical images at other wavelengths of light. D³PO was developed by Marco Selig during his just-completed doctorate with honors at the Ludwig-Maximilians-Universität München (Fig. 3). The algorithm was derived within information field theory and implemented using the also freely available NIFTY-software for numerical information field theory. Information field theory deals with the mathematics of imaging complex data sets and is a central focus of the research group of Torsten Ensslin at the Max Planck Institute for Astrophysics.
Marco Selig, Valentina Vacca, Niels Oppermann, Torsten Enßlin.