Lateral width of shower image in the Auger fluorescence detector
  The impact of the lateral distribution of light in extensive air showers on the detection and reconstruction of shower profiles is investigated for the Auger fluorescence telescopes. Based on three-dimensional simulations, the capability of the Auger telescopes to measure the lateral distribution of light is evaluated. The ability to infer the actual lateral distribution is confirmed by the comparison of detailed simulations with real data. The contribution of pixels located far from the axis of the shower image is calculated and the accepted signal is rescaled in order to reconstruct a correct shower profile. The analysis presented here shows that: (a) the Auger telescopes are able to observe the lateral distribution of showers and (b) the energy corrections to account for the signal in outlying pixels can exceed 10%, depending on shower geometry. 
H. Barbosa, V. de Souza, C. Dobrigkeit, R. Engel, D. Gora, D. Heck, P.   Homola, H. Klages, G. Medina-Tanco, J.A. Ortiz, J. ...