Broad relativistic iron lines from neutron star X-ray binaries are important probes of the inner accretion disk .
The X-ray reflection features can be weakened due to strong magnetic fields or very low iron abundances such as is possible in X-ray binaries with low mass , first generation stars as companions .
Here we investigate the reality of the broad iron line detected earlier from the neutron star low mass X-ray binary 4U 1820–30 with a degenerate helium dwarf companion .
We perform a comprehensive , systematic broadband spectral study of the atoll source using Suzaku and simultaneous NuSTAR & Swift observations .
We have used different continuum models involving accretion disk emission , thermal blackbody and thermal Comptonization of either disk or blackbody photons .
The Suzaku data show positive and negative residuals in the region of iron K band .
These features are well described by two absorption edges at 7.67 \pm 0.14 { ~ { } keV } and 6.93 \pm 0.07 { ~ { } keV } or partial covering photoionized absorption or by blurred reflection .
Though , the simultaneous Swift and NuSTAR data do not clearly reveal the emission or absorption features , the data are consistent with the presence of either absorption or emission features .
Thus , the absorption based models provide an alternative to the broad iron line or reflection model .
The absorption features may arise in winds from the inner accretion disk .
The broadband spectra appear to disfavour continuum models in which the blackbody emission from the neutron star surface provides the seed photons for thermal Comptonization .
Our results suggest emission from a thin accretion disk ( kT _ { disk } \sim 1 { ~ { } keV } ) , Comptonization of disk photons in a boundary layer most likely covering a large fraction of the neutron star surface and innermost parts of the accretion disk , and blackbody emission ( kT _ { bb } \sim 2 { ~ { } keV } ) from the polar regions .