Project description
Observing gas flows around galaxies and how they shape galaxy evolution
Galaxies are systems of billions of stars, gas, and dust, all held together by gravity. Due to the mutual interactions between these components, the internal structure of a galaxy changes over time. An essential actor in these transformations is the circumgalactic medium (CGM), a huge dynamic reservoir of gas. Matter flows from the CGM into the galaxy to form new stars, but it also gets driven out by explosions inside the galaxy. The EU-funded SPECMAP-CGM project will use two uniquely sensitive instruments at leading observatories and exploit novel detection methods to spectroscopically map hundreds of galaxies at once, detect the faint emission from the CGM, and thus constrain the complex processes that shape galaxy evolution.
Objective
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.
Fields of science
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Funding Scheme
ERC-ADG - Advanced GrantHost institution
14482 Potsdam
Germany