A possible common explanation for several cosmic microwave background (CMB) anomalies: A strong impact of nearby galaxies on observed large-scale CMB fluctuations

Understand

In Luparello et al.

• 2023, a new and hitherto unknown CMB foreground was detected.
• A systematic decrease in Cosmic Microwave Background (CMB) temperatures around nearby large spiral galaxies points to an unknown interaction with CMB photons in a sphere up to several projected Mpc around these galaxies.
• We investigate to which extent this foreground may impact the CMB fluctuations map and create the so-called CMB anomalies.