Spectroscopic modelling of two high-mass X-ray binaries, Cyg X–3 and 4U 1538–522

We report a detailed modelling of soft X-ray emission lines from two stellar-wind fed Galactic high mass binary (HMXB) systems, Cyg X-3 and 4U 1538-522, estimate physical parameters, e.g., hydrogen density, radiation field, chemical abundances, wind velocity, etc. The spectral synthesis code CLOUDY is utilized for this modelling. model highly ionised such as Fe XXV (6.700 keV), XXVI (6.966 reproduce the observed line flux values. find that X--3 inner radius gas at distance 10$^{12.25}$ cm 10$^{10.43}$ respectively primary star, which main source ionisation. densities 1538--522 are found to be $\sim$ 10$^{11.35}$ cm$^{-3}$ 10$^{11.99}$ cm$^{-3}$, respectively. corresponding velocities 2000 km s$^{-1}$ 1500 s$^{-1}$. respective predicted column $10^{23.2}$ cm$^{-2}$ 10$^{22.25}$ cm$^{-2}$. In addition, we magnetic field affects strength through cyclotron cooling. Hence, perform separate comparisons including both sources. Most except have similar values with without field. most probable 1538--522, where originate, 10$^{2.5}$G.