The Axis of Evil revisited

In light of the three-year data release from the Wilkinson Microwave Anisotropy Probe, we re-examine the evidence for the ‘Axis of Evil’ (AoE). We discover that previous statistics are not robust with respect to the data sets available and different treatments of the Galactic plane. We identify the cause of the instability and implement an alternative ‘model selection’ approach. A comparison to Gaussian isotropic simulations finds the features significant at the 94–98 per cent level, depending on the particular AoE model. The Bayesian evidence finds lower significance, ranging from ‘substantial’ at Δ(ln E) ∼ 1.4 to no evidence for the most general AoE model.