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« Signatures of AGN feedback on the Lyman-alpha forest  »

Solène Chabanier
Service Astroph. (DAPNIA/SAp), CEA-Saclay (Gif-sur-Yvette, France)

Neutral hydrogen in the Intergalactic Medium produces a collection of Lyman-alpha absorptions, called the Lyman-alpha forest, seen in the spectra of background objects. According to the common paradigm, neutral hydrogen in the IGM evolves from primordial density fluctuations in a low density and photo-ionized environment. It therefore acts as a direct tracer of dark matter.
As the current uncertainties of Lya measurements are at the percent level, and will even shrink further with future Lyman-alpha surveys, the lyman-alpha forest becomes sensitive to complex mechanical effects known as AGN feedback that mitigate cosmological signatures.
We use Adaptative Mesh Refinement (AMR) hydrodynamical simulations, the Horizon-AGN and ExtremeHorizon simulations, to evaluate its impact on the Lya forest and prevent degeneracies with cosmological parameters.
mardi 31 mars 2020 - 10:30
Webinaire, Institut d'Astrophysique
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