  We investigate the X-ray spectrum of the Seyfert galaxy NGC 4151 using the
simultaneous Suzaku/NuSTAR observation and flux-resolved INTEGRAL spectra
supplemented by Suzaku and XMM observations. Our best spectral solution
indicates that the narrow Fe Kalpha line is produced in Compton-thin matter at
the distance of several hundred gravitational radii. In such a model, we find a
weak but significant relativistic reflection from a disk truncated at about ten
gravitational radii when the source is in bright X-ray states. We do not find
evidence either for or against the presence of relativistic reflection in the
dim X-ray state. We also rule out models with X-ray emission dominated by a
source located very close to the black hole horizon, which was proposed in
previous works implementing the lamp-post geometry for this source. We point
out that accurate computation of the thermal Comptonization spectrum and its
distortion by strong gravity is crucial in applications of the lamp-post
geometry to the NuSTAR data.

High Energy Astrophysical Phenomena