Unraveling fast non-equatorial disk-wind and high-density disk reflection in MAXI J1348-630

Disk reflection and disk wind are two seemingly disconnected phenomena in the X-ray spectra of Black Hole X-ray binaries, providing independent probes to constrain important physical parameters associated with the accretion disks (e.g., inclination and density). A synergy between reflection and absorption spectroscopy, therefore, can provide unprecedented insight into the physical conditions of the disk. In this work, we demonstrate this union using broadband spectral analysis of all the six hard, intermediate and soft state NuSTAR observations of the low-mass black hole X-ray binary MAXI J1348-630 during its first outburst in 2019. Using high-density disc reflection models, we find the disk density and inclination to be 10^(20.3-21.4) cm^-3 and ~30-50 degrees, respectively. We also find evidence of a high-velocity wind in the form of blue-shifted Fe K (at ~7.3 keV) absorption lines. We then carry out the first direct MHD modelling of non-equatorial fast outflows in an X-ray binary, with MAXI J1348-630. We find that an MHD wind of density at the base of the wind 10^(19-21) cm^-3 and an inclination of 30-40 degrees can account for the absorption line throughout all of its spectral states. This broad consistency between the best-fit parameters of the two mutually exclusive methods provides credence to our novel approach.