Models of the HLE X-ray emission (0.3 − 10) keV of GW170817. Blue and orange lines denote on-axis and off-axis (θ_v = 15°) views and solid and dotted lines mark models with R₀ = 2 × 10¹⁵ cm and R₀ = 10¹³ cm, respectively. Swift-XRT (0.3–10) keV and MAXI (2–10) keV upper limits are shown by the gray and red triangles, respectively. The purple vertical line represents the trigger time of GRB 170817A with respect to the GW signal. A power-law structured jet is assumed (from Ghirlanda et al. 2019) with Γ_c = 251, θ_c = θ_E = 3.4°, E_K,ISO = 2.5 × 10⁵² erg, and power-law slope k_c = 3.5 and k_E = 5.5 for the energy and bulk Lorentz factor, respectively. A SBPL with hν_peak = 100 keV, α_s = 0.5, and β_s = 1.3 is assumed.