4–5 Jun 2026
University of Geneva
Europe/Zurich timezone

Bound or blown: the fate of hot gas in galaxy groups

5 Jun 2026, 14:30
15m
Sciences II Auditorium A100 (University of Geneva)

Sciences II Auditorium A100

University of Geneva

Quai Ernest-Ansermet 30

Speaker

Riccardo Seppi (University of Geneva)

Description

Upcoming cosmological surveys aim to measure the matter power spectrum with percent-level precision, but baryonic effects, in particularly AGN feedback, remain a major source of systematic uncertainty, suppressing power on small scales. Constraining how feedback redistributes gas in dark matter haloes is therefore essential for robust cosmological inference.

Galaxy groups, with their shallow potentials, are especially sensitive to feedback and provide a powerful testbed. We compare thermodynamic properties of galaxy groups from the X-GAP sample with the FLAMINGO simulation suite using a fully forward-modelled approach that accounts for selection effects and X-ray measurement systematics.

We find that intermediate feedback models best reproduce the observed scaling relations, while both weaker and more extreme scenarios are disfavoured. This tension with other probes highlights the current uncertainty in baryonic physics and its direct impact on matter power spectrum suppression.

Author

Riccardo Seppi (University of Geneva)

Co-author

Dominique Eckert (Department of Astronomy, University of Geneva)

Presentation materials