Measurements of the Muon Content of UHECR Air Showers with the Pierre
  Auger Observatory
  The Pierre Auger Observatory, recently completed, has been operational since
2004. As a hybrid experiment, it allows for a wide range of measurements of
UHECR-induced extensive air showers (EAS), including measurements of the EAS
particle content on ground which is sensitive to high-energy hadronic
interactions. We present the results of several independent measurements of the
EAS muon content on ground in Auger data at a primary energy of 10 EeV. We
discuss implications on high-energy hadronic interaction models and cosmic ray
composition.
