Effects of boosting on extragalactic components: methods and statistical studies
Abstract
In this work, we examine the impact of our motion with respect to the Cosmic Microwave Background (CMB) rest frame on statistics of CMB maps by examining the one, two, three, and four point statistics of simulated maps of the CMB and SunyaevZeldovich (SZ) effects. We validate boosting codes by comparing their outcomes for temperature and polarization power spectra up to ℓ ≃ 6000. We derive and validate a new analytical formula for the computation of the boosted power spectrum of a signal with a generic frequency dependence. As an example we show how this increases the boosting correction to the power spectrum of CMB intensity measurements by ${\sim}30{{\ \rm per\ cent}}$ at 150 GHz. We examine the effect of boosting on thermal and kinetic SZ power spectra from semianalytical and hydrodynamical simulations; the boosting correction is generally small for both simulations, except when considering frequencies near the tSZ null. For the nonGaussian statistics, in general we find that boosting has no impact with two exceptions. We find that, whilst the statistics of the CMB convergence field are unaffected, quadratic estimators that are used to measure this field can become biased at the $O(1){{\ \rm per\ cent}}$ level by boosting effects. We present a simple modification to the standard estimators that removes this bias. Second, bispectrum estimators can receive a systematic bias from the Doppler induced quadrupole when there is anisotropy in the sky  in practice this anisotropy comes from masking and inhomogeneous noise. This effect is unobservable and already removed by existing analysis methods.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 June 2022
 DOI:
 10.1093/mnras/stac1017
 arXiv:
 arXiv:2112.10228
 Bibcode:
 2022MNRAS.513.2252C
 Keywords:

 cosmic background radiation;
 cosmology: observations;
 largescale structure of Universe;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 21 pages and 14 figures