Fredagskollokvium: Simulating CIB for Future CMB Missions

The quality of the observed cosmic microwave background (CMB) signal depends on the accuracy of the separation of the astrophysical foreground components from the data, which requires building simulations as close to the complexity of the real sky as possible over a large frequency range. To this end, a complete model of multi-component sky emission, called the Planck sky model (PSM), has been developed.

The weak gravitational lensing of the CMB is a limiting factor for the detection of the primordial polarisation signal from inflationary gravitational waves. Future CMB missions with sensitive, high-resolution observations can be used to reconstruct the lensing deflection field, which is significantly correlated with the tracers of large-scale structure such as the cosmic infrared background (CIB). This correlation can be exploited to increase the performance of the CMB delensing methods. A CMB model is implemented in the PSM for which the lensing potential is correlated with density fluctuation fields at different redshift shells. The density contrast maps are then used to simulate the CIB sky. The simulated CIB signal and the lensing potential reconstructed from the simulated CMB sky are in good agreement with the Planck observations, suggesting that they can be used to validate the performance of delensing methods that use CIB as a tracer for lensing.