Impact of reflection Comptonization on X-ray reflection spectroscopy: the case of EXO 1846-031

Abstract

Within the disk-corona model, it is natural to expect that a fraction of reflection photons from the disk are Compton scattered by the hot corona (reflection Comptonization), even if this effect is usually ignored in X-ray reflection spectroscopy studies. We study the effect by using NICER and NuSTAR data of the Galactic black hole EXO 1846-031 in the hard-intermediate state with the model SIMPLCUTX. Our analysis suggests that a scattered fraction of order 10% is required to fit the data, but the inclusion of reflection Comptonization does not change appreciably the measurements of key-parameters like the black hole spin and the inclination angle of the disk.