EXOSAT observations of the galactic bulge X-ray source GX17+2

The X-ray flux of the bright galactic bulge source GX17+2 was measured in the energy range 1 to 20 keV by the EXOSAT ME experiment. During 8 hr continuous observation an X-ray flare was observed (lasting 1 hr) followed by an intensity increase. The data show intensity dips with a quasiperiod of 1.4 hr and quasi-periodic oscillations on a time scale of 200 to 500 sec, possibly connected with oscillations of an accretion disk. The spectrum can be fitted by two black body spectra with kT1 = 1keV, and kT2 = 2keV, respectively, and an iron line at 6.3 + or - 0.3 keV having 130 eV equivalent width. While the low energy component is stable, the 2keV component shows considerable intensity variations. It is suggested that the latter component represents emission from the inner part of the accretion disk while the soft spectrum is black body emission from the surface of the neutron star.