A broad iron line in the Chandra/HETG spectrum of 4U 1705–44

Abstract We present preliminary results from a Chandra 30 ks observation of the atoll source 4U 1705–44. In particular we concentrate on the study of discrete features in the energy spectrum at energies below ∼3 keV, as well as the iron Kα line, using the HEG spectrometer on board of the Chandra satellite. The iron Kα line at ∼6.6 keV is found to be intrinsically broad (FWHM ∼ 1.7 keV); its width can be explained by reflection from a cold accretion disk extending down to ∼17 km from the neutron star center or by broadening in the hotter (∼ 3–4 keV) Comptonizing corona.