Measurement of the average electromagnetic longitudinal shower profile at the Pierre Auger Observatory

Abstract

In addition to the standard X$_{max}$ and energy, the longitudinal profiles of extensive air showers contain some more interesting information. For energies above 10$^{17:8}$ eV, we present the average profiles as a function of atmospheric depth measured for the first time at the Pierre Auger Observatory. The profile shapes for different energy ranges are all well reproduced by a Gaisser- Hillas function within the range studied. A detailed analysis of the systematic uncertainties is performed using data and a full detector simulation, and the results are compared with predictions of hadronic interaction models for different primaries.