The X-ray spectrum of the black hole candidate GX339-4 in a low state

Abstract

We report on four observations of the black hole candidate GX 339-4 collected in the spectral range 0.4-140 keV with the BeppoSAX satellite during 1997. All our spectra are typical of a black hole candidate in its low-hard state, i.e. are dominated by the hard tail of the emission from the corona. Although the direct emission from the accretion disk in the soft X-ray range is weak, spectra are well described only with models that take into consideration the Compton reflection of hard X-rays from the corona onto the surface of an accretion disk of non negligible extent.