Systematic Effects in the Measurement of Large Scale Anisotropies

The High Altitude Water Cherenkov (HAWC) Observatory detects cosmic rays and gamma rays in the multi-TeV energy range. An unexpected, and still unexplained, large scale anisotropy is observed in the spatial distribution of the arrival directions of the air showers (initiated by both cosmic rays and gamma rays). I studied the arrival directions of both cosmic rays and gamma rays detected with the HAWC Observatory as a function of energy. I also compared my observations with simulated air showers. I will present the observed oscillations in local azimuth and a comparison with the expectations.