THE COMPTONIZED X-RAY SOURCE X 1724-308 IN THE GLOBULAR-CLUSTER TERZAN-2

We report on the BeppoSAX observation of the X-ray source X 1724-308 i n the globular cluster Terzan 2. The broadband spectrum can be describ ed as the superposition of a power-law with photon spectral index Gamm a similar or equal to 1.6 - 1.9 and a thermal component with typical t emperature kT similar to 1 keV. X 1724-308 is detected in the PDS up t o 150keV with a S/N ratio >3, notwithstanding a sharp exponential cuto ff with E-cutoff similar or equal to 90 keV. The broadband spectrum ca n be best interpreted as due to the Comptonization of a Wien photon di stribution with kT(w) similar to 1keV by a spherically-symmetric hot p lasma with electron temperature kT(e) similar to 30 keV and optical de pth tau similar or equal to 3. A comparison with the fainter and steep er state, which was observed by EXOSAT, suggests a correlation between the temperature of the Comptonizing electron distribution (or the pla sma optical depth) and the X-ray intensity. The X-ray thermal componen t could originate from a boundary layer between the accretion disk and the compact object, or from the accretion disk itself.