Colloquium on Apr. 30, 2026

Self-consistent CMB secondaries in the FLAMINGO simulations

Speaker: Tianyi Yang (Liverpool John Moores University)

Venue: SWIFAR Building 2111

Time: 16:00 PM, Thursday, Apr. 23, 2026

Abstract:

Secondary anisotropies in the cosmic microwave background (CMB) contain a wealth of cosmological and astrophysical information.  However, cleanly separating the individual contributions of the various kinds of anisotropies from each other can be a very challenging task, owing to uncertainties in their spatial, temporal, and spectral dependencies.  Realistic mock simulations of the CMB sky are invaluable for testing our methods of separating out the various signals and for making like-with-like comparisons between theory and observations.  Previous mocks have relied mostly on dark matter-only simulations with various prescriptions for "painting on" astrophysical signals.  Here we present a new set of mocks based on the FLAMINGO suite of cosmological hydrodynamical simulations, where the various anisotropies (tSZ, kSZ, screening, CIB, lensing, radio sources) are derived directly from the properties of the matter, gas and accreting black holes in the simulations.  We show that the simulations can reproduce various observational constraints with high accuracy.  We also show how these signals depend on cosmology and feedback modelling, and we predict interesting cross-correlations between some of the signals that differs significantly from that predicted by previous mocks.