Fundamental Research Division
The DRF at the CEA assemble approximately 6,000 scientists since January 2016.
Scientific result | Galaxies
The researchers wanted to compare the shape of galaxies with and without an active nucleus during the "peak" of structure formation in the universe (8 billion years ago), with identical star formation rate and stellar masses. Active nuclei that were hidden behind giant dust clouds were selected so that their visible counterpart would not distort the image of the host galaxy. In this case the nuclei are easily identified in both infrared and X-rays.
The team found that the galaxies hosting active nuclei are significantly smaller and more compact than others. The astrophysicists therefore deduced that the gas masses needed for the growth of the supermassive black hole could be channeled towards the central region due to violent gravitational instabilities inside the disk formed by the stars of the galaxy. These instabilities would trigger an important contraction of the galaxy, hence its ultra-compact morphology.
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.