Spectro-polarimetric properties of model (A) of a slab corona of T _e = 100 keV and T _bb = 0.1 keV with the outflow of terminal velocity β ₀ = 0.4. (a) Spectral energy distribution of the escaping radiation at inclination i = 30° scaled to produce the angle-integrated bolometric luminosity of L = 10³⁷ erg s⁻¹. Blue solid, dotted, dashed, dotted–dashed, triple-dotted–dashed, and long-dashed lines show the contribution of different scattering orders n = 0, 1, 2, 4, 7, and 10, respectively. The black solid line gives the total spectrum. (b) The PD as a function of energy at the same inclination for the total radiation (black solid) and for different scattering orders is shown. (c) Angular distribution of the intensity at optical depth τ = (3/4)τ ₀ (where β = 0.3) for the same scattering orders as above at the corresponding peaks of EI _E . The black and red curves correspond to the lab and comoving frame intensities, respectively. The lab-frame intensities are normalized to unity at the maximum. (d) Angular dependence of PD for the same scattering orders at the same energies as the intensity. The IXPE energy range is marked by a beige vertical stripe in panels (a) and (b).