Description du projet
Observer les flux de gaz autour des galaxies et comment ils façonnent leur évolution
Les galaxies sont des systèmes de milliards d’étoiles, de gaz et de poussière, maintenus ensemble par la gravité. Les interactions mutuelles entre ces composants modifient la structure interne d’une galaxie dans le temps. Un acteur essentiel de ces transformations est le milieu circumgalactique (CGM), immense réservoir dynamique de gaz. La matière s’écoule du CGM dans la galaxie pour former de nouvelles étoiles, mais elle est également chassée par des explosions à l’intérieur de la galaxie. Le projet SPECMAP-CGM, financé par l’UE, utilisera deux instruments d’une sensibilité unique dans des observatoires de pointe et exploitera de nouvelles méthodes de détection pour cartographier par spectroscopie des centaines de galaxies à la fois, détecter la faible émission du CGM et ainsi contraindre les processus complexes qui façonnent l’évolution des galaxies.
Objectif
This project aims at developing a radically new view on the structure and dynamics of gas flows in the surroundings of galaxies, a domain known as the circumgalactic medium (CGM). In the last years it became clear that the CGM is crucial for our understanding of galaxy evolution, which are largely shaped in the CGM by the interplay of inflows from the intergalactic medium and outflows driven by supergalactic winds. I plan to investigate the CGM of normal galaxies by means of integral field spectroscopy, or spectro-mapping, in various emission lines. I bring privileged access to two new major astronomical facilities, MUSE on the ESO Very Large Telescope in Chile, and HETDEX on the 10m Hobby-Eberly Telescope in Texas. These instruments are both unique in their capability of performing integral field spectroscopy over unprecedented fields of view, delivering high-quality spectro-mapping information for hundreds of galaxies and their circumgalactic environments simultaneously. I have a leading role in both, and I am the only astronomer in the world with direct access to MUSE Guaranteed Time Observations and to the entire HETDEX survey. The major challenge for this experiment is the extreme faintness of the CGM emission, which so far made spectro-mapping unfeasible except for a few extreme objects. My recent breakthrough discoveries with MUSE of ubiquitous Lyman-alpha haloes around high-redshift galaxies demonstrate that finally we have achieved the sensitivity required to detect the CGM directly in emission through imaging spectroscopy. I now want to go a big step beyond and apply this approach to large representative samples of typical galaxies at all redshifts. My goal is not only to detect and establish line emission from the CGM as a universal phenomenon, but to disantangle its complex substructures and, through comparisons with physical models and the latest numerical galaxy formation simulations, build a comprehensive picture of these processes.
Champ scientifique
Programme(s)
Thème(s)
Régime de financement
ERC-ADG - Advanced GrantInstitution d’accueil
14482 Potsdam
Allemagne