Can extragalactic foregrounds explain the large-angle CMB anomalies?

Abstract

We address the effect of an extended local foreground on the low-l anomalies found in the CMB. Recent X-ray catalogues point us to the existence of very massive superstructures at the 100 h^(-1) Mpc scale that contribute significantly to the dipole velocity profile. Being highly non-linear, these structures provide us a natural candidate to leave an imprint on the CMB sky via a local Rees-Sciama effect. We show that the Rees-Sciama effect of local foregrounds can induce CMB anisotropy of DeltaT/T ~ 10^(-5) and we analyse its impact on multipole power as well as the induced phase pattern on largest angular scales.