  The X-ray source 4U 1822-371 is an eclipsing low-mass X-ray binary and X-ray
pulsar, hosting a NS that shows periodic pulsations in the X-ray band. The
inclination angle of the system is so high that in principle, it should be hard
to observe both the direct thermal emission of the central object and the
reflection component of the spectrum because they are hidden by the outer edge
of the accretion disc. Assuming that the source accretes at the Eddington
limit, we analysed non-simultaneous XMM-Newton and NuSTAR observations and
studied the average broadband spectrum, with the aim to investigate the
presence of a reflection component. No such component has been observed before
in a high-inclination source such as 4U 1822-371. We modelled the spectral
emission of the source using two different reflection models, Diskline plus
Pexriv and the self-consistent model RfxConv. In our analysis, we find
significant evidence of a reflection component in the spectrum, in addition to
two lines associated with neutral or mildly ionised iron. The continuum
spectrum is well fitted by a saturated Comptonisation model and a thermal
black-body component emitted by the accretion disc at a lower temperature. We
updated the ephemeris, adding two new eclipse times to the most recent
ephemeris reported in literature. In our proposed scenario, the source is
accreting at the Eddington limit with an intrinsic luminosity of $10^{38}$
erg/s, while the observed luminosity is two orders of magnitude lower. Despite
the high inclination, we find that a reflection component is required to fit
residuals at the Fe line range and the hard excess observed in the spectrum.
The best-fit value of the inner disc radius is still uncertain and model
dependent. More observations are therefore needed to confirm these results,
which can give important information on this enigmatic and peculiar source.

High Energy Astrophysical Phenomena