Constraints on the physical origin of disk winds in Black Hole X-ray binaries thanks to Athena

The last two decades have seen a series of discoveries of narrow blue-shifted absorption features in transient BH LMXB. These features could actually trace massive equatorial outflows that can be dynamically important for the evolution of these systems. All high-inclination sources show these powerful disk winds especially during the soft state, mainly traced by the presence of ionized iron lines (e.g., Fexxv and/or Fexxvi). These winds are however typically absent during the hard state. Nonetheless, a large variety of wind signatures (generally strongly variable) and behaviors exist, revealing a complex connection among winds, jets and the states of the accretion disk. Our precise knowledge of the physical properties (density, ionisation, velocity profiles) of these winds is still quite poor however. For example we still do not know if the wind dynamics is mainly controlled by magnetically or thermally driven mechanisms, both being among the most probable launching mechanisms. We will show in this study, through state-of-the-art simulations, the decisive breakthroughs, in terms of physical diagnostics of the wind properties, we can expect from the high sensitivity and unprecedented spectral resolution of Athena in our understanding of BH LMXB wind and of their impact on the accretion-ejection processes