  We analyzed 252 hours of High Energy Stereoscopic System (H.E.S.S.)
observations towards the supernova remnant (SNR) LMC N132D that were
accumulated between December 2004 and March 2016 during a deep survey of the
Large Magellanic Cloud, adding 104 hours of observations to the previously
published data set to ensure a > 5 sigma detection. To broaden the gamma-ray
spectral coverage required for modeling the spectral energy distribution, an
analysis of Fermi-LAT Pass 8 data was also included. We unambiguously detect
N132D at very high energies (VHE) with a significance of 5.7 sigma. We report
the results of a detailed analysis of its spectrum and localization based on
the extended H.E.S.S. data set. The joint analysis of the extended H.E.S.S and
Fermi-LAT data results in a spectral energy distribution in the energy range
from 1.7 GeV to 14.8 TeV, which suggests a high luminosity of N132D at GeV and
TeV energies. We set a lower limit on a gamma-ray cutoff energy of 8 TeV with a
confidence level of 95%. The new gamma-ray spectrum as well as multiwavelength
observations of N132D when compared to physical models suggests a hadronic
origin of the VHE gamma-ray emission. SNR N132D is a VHE gamma-ray source that
shows a spectrum extending to the VHE domain without a spectral cutoff at a few
TeV, unlike the younger oxygen-rich SNR Cassiopeia A. The gamma-ray properties
of N132D may be affected by an interaction with a nearby molecular cloud that
partially lies inside the 95% confidence region of the source position.
[Abridged]
