... the spectral properties observed in X-rays from neutron star X-ray binary 4U 1728-34 ... in the transition layer (TL) between the accretion disk and neutron star surface ... of the source was previously suggested for a number of other neutron binaries ...
... of all accreting compact systems, including neutron sources too (see Titarchuk ... binaries containing a number of low-magnetic-field neutron stars and one BH GX 339-4 ...
... likely a black hole (BH), or possibly a neutron star (see, e.g., Cherepashchuk 2002 ... 4333 which clearly does not rule out a neutron star--this limit alone does not give ... In contrast, in neutron star sources the photon index is almost constant ...
... Thus, we can suggest that this spectral stability property is a spectral signature of an accreting neutron star source. ... INTRODUCTION Accreting neutron stars (NSs) can be observationally classified into two distinct categories using a colorcolor ...