  We have performed a detailed study of the broadband spectra of the luminous
globular cluster X-ray sources using BeppoSAX. With the exception of X2127+119,
located in NGC7078, all the other spectra are well represented by a two
component model consisting of a disk-blackbody and Comptonized emission. The
measured low-energy absorptions are in good agreement with those predicted from
optical measurements of the host globular clusters. This implies that there is
little intrinsic X-ray absorption within the binaries themselves, and that the
above spectral model provides a good representation of the low-energy continua.
The sources can be divided into two groups. In the first group, composed of 3
ultra-compact (orbital period <1hr) sources, the disk-blackbody temperatures
and inner-radii appear physically realistic and the Comptonization seed photons
temperatures and radii of the emission areas are consistent with the disk
temperatures and inner radii. For all the other sources, the disk-blackbody
parameters appear not to be physically realistic and the Comptonization
parameters are unrelated to those of the disk-blackbody emission. If this is a
spectral signature of ultra-compact binaries, this implies that no other
ultra-compact binaries are present among those studied here. It is unclear why
this difference between the two types of binaries should exist.
