Investigating the Accretion Structure of Vela X−1 and Cyclotron Resonant Scattering Features in GX 301−2

Abstract

This thesis presents X-ray spectroscopic studies of the wind-fed high-mass X-ray binaries Vela X−1 and GX 301−2 using XMM-Newton and NuSTAR observations. For Vela X−1, the analysis reveals a complex, multi-phase stellar wind, evidence for X-ray reflection, and iron abundances below the assumed solar values, providing new insights into the accretion structure. For GX 301−2, our analysis confirms the presence of a cyclotron resonant scattering feature near 35 keV, while the origin of a second feature near 50 keV remains uncertain due to spectral model degeneracies and the increasing background contribution at higher energies. Together, these results provide new observational constraints on the accretion environments and X-ray spectral properties of both systems.