  We present the results of a broad-band X-ray study of the enigmatic Be star
Gamma Cassiopeiae (herein gamma Cas) based on observations made with both the
Suzaku and INTEGRAL observatories. gamma Cas has long been recognized as the
prototypical example of a small subclass of Be stars with moderately strong
X-ray emission dominated by a hot thermal component in the 0.5-12 keV energy
range Lx ~ 10^32 - 10^33 erg s^-1. This places them at the high end of the
known luminosity distribution for stellar emission, but several orders of
magnitude below typical accretion powered Be X-ray binaries. The INTEGRAL
observations spanned an 8 year baseline and represent the deepest measurement
to date at energies above ~50 keV. We find that the INTEGRAL data are
consistent within statistics to a constant intensity source above 20 keV, with
emission extending up to ~100 keV and that searches for all of the previously
reported periodicities of the system at lower energies led to null results. We
further find that our combined Suzaku and INTEGRAL spectrum, which we suggest
is the most accurate broad-band X-ray measurement of gamma Cas to date, is
fitted extremely well with a thermal plasma emission model with a single
absorption component. We found no compelling need for an additional non-thermal
high-energy component. We discuss these results in the context of a currently
favored models for gamma Cas and its analogs.
