First INTEGRAL Observations of Eight Persistent Neutron Star Low Mass X-ray Binaries

Abstract

Early results from the INTEGRAL Core Program, for a sample of eight persistently bright neutron star low mass X-ray binaries in the energy range from 5 keV to 200 keV are presented. It is shown that INTEGRAL efficiently detects sources and that spectra may be obtained up to several hundreds of keV by combining data from three of the four INTEGRAL instruments: JEM-X, IBIS and SPI. For the source GX 17+2 it is shown that the spectrum extends well above 100 keV with a flattening of the spectrum above 30 keV. This might suggest a non-thermal comptonisation emission, but uncertainties in the current data reduction and background determination do not allow firm conclusions to be drawn.