Biases to primordial non-Gaussianity measurements from CMB secondary anisotropies

Our view of the last-scattering surface in cosmic microwave background (CMB) is obscured by secondary anisotropies, sourced scattering, extragalactic emission and gravitational processes between recombination observation. Whilst it established that non-Gaussianity from correlation integrated-Sachs-Wolfe (ISW) effect lensing can significantly bias primordial (PNG) searches, recent work Hill (2018) has suggested other combinations anisotropies also produce significant biases. Building on work, we use WebSky Sehgal et al.(2010) simulations to perform an extensive examination possible biases PNG measurements for local, equilateral orthogonal shapes. For a Planck-like CMB experiment, without foreground cleaning, find infrared (CIB)-lensing thermal Sunyaev-Zel'dovich (tSZ)-lensing bispectra local templates, CIB tSZ template. future experiments, such as Simons Observatory, correlations ISW will become important. Finally investigate whether foreground-cleaning techniques are able suppress these sufficiently. We majority effectively suppressed internal-linear-combination method total SO-like experiments less than $1\,\sigma$ statistical error. However, small arises cancellation several $2\,\sigma$ SO-like. As this likely sensitive precise modelling, ensure robustness against explicit removal methods should be used, at cost decreased constraining power.