H.E.S.S. upper limit on the very high energy gamma-ray emission from the
  globular cluster 47 Tucanae
  Observations of the globular cluster 47 Tucanae (NGC 104), which contains at
least 23 millisecond pulsars, were performed with the H.E.S.S. telescope
system. The observations lead to an upper limit of F(E>800 GeV) < 6.7e-13 /
cm^2 s on the integral gamma-ray photon flux from 47 Tucanae. Considering
millisecond pulsars as the unique potential source of gamma-rays in the
globular cluster, constraints based on emission models are derived: on the
magnetic field in the average pulsar nebula and on the conversion efficiency of
spin-down power to gamma-ray photons or to relativistic leptons.
