CMB Isotropy Anomalies and the Local Kinetic Sunyaev-Zel'dovich Effect

Understand

Several anomalies have been identified which may imply a breakdown of the statistical isotropy of the cosmic microwave background (CMB).

• In particular, an anomalous alignment of the quadrupole and octopole and a hemispherical power asymmetry have increased in significance as the data have improved.
• There have been several attempts to explain these observations which explore isotropy breaking mechanisms within the early universe, but little attention has been given to the possibility that these anomalies have their origin within the local universe.
• We explore such a mechanism by considering the kinetic Sunyaev-Zel'dovich effect due to a gaseous halo associated with the Milky Way.