Orateur
Description
Extracting the kinematic Sunyaev-Zel'dovich (kSZ) effect—the Compton scattering of CMB photons off moving electrons—requires cleaning of other sky components. In this work, we use large-scale structure (LSS) tracers that are correlated with both the cosmic infrared background (CIB) and thermal Sunyaev-Zel'dovich (tSZ) signal, but whose two-point correlations with the kSZ signal vanish on small scales due to the equal likelihood of positive and negative velocities. We consider various methods involving these LSS tracers to remove the CIB and tSZ contaminants without biasing the kSZ signal. In particular, we use the unWISE galaxy samples as tracer maps. We present our primary methods of interest, de-CIBing and de-(CIB+tSZ)ing, methods analogous to delensing, as ways to use these tracers to clean the CIB and tSZ signals without requiring exact assumptions about the CIB spectral energy distribution. We then explore comparisons of these methods to internal linear combination (ILC) methods, as well as combinations of both types of approaches. We provide specific calculations for a combined Simons Observatory and Planck-like experiment, with our simulated sky model consisting of component auto- and cross- spectra generated with $\verb|class_sz|$ at six frequencies ranging from 93 to 353 GHz. Our code is publicly available in $\verb|ILC_deCIB|$. For current data, improvements with these methods over current approaches are already non-negligible, and will become more significant with larger LSS surveys in the future.
