A Mollweide projection of the Asimov test statistic for the location on the sphere of the boost velocity of the Sagitarrius stream. Brighter locations indicate those locations which are preferred by a likelihood analysis of the interference effect which arises in the analysis of axion direct detection data simultaneously collected at two spatially separated locations. By leveraging the daily modulation of the separation of the two detectors which are confined to the Earth's surface, an increasingly precise determination of the boost orientation can be made. Each frame shows the improvement to the localization based on an additional hour of data collection over a 24 hour collection period.
This animation additionally compares the localization for configurations where the detectors are oriented along the East-West (North-South) direction with respect to one another in the left (right) panel. The North-South configuration leads to a better localization since there is a unique global maximum in the Asimov test statistic, whereas the East-West configuration produces an exact degeneracy between two global minima. For more details, see the main work.