SED of 1RXS J101015.9 - 311909 (Abramowski et al. 2012b, ; the H.E.S.S. spectrum is represented by the green bow-tie and the blue points, the Fermi-LAT spectrum by the orange bow-tie and the red empty circles; Swift-XRT data are shown by the pink crosses, Swift-UVOT data by the red stars, ATOM data by the blue open boxes, and archival data from the NED in grey). All the SSC models which describe the SED, as found with our algorithm, are plotted in grey, while the solid black curve represents the best-fit solution with . It is characterised by an extreme value of δ = 96.83, B = 0.015 G, R = 1.3 × 10¹⁶ cm, α₁ = 2.0, K′ = 8.94 × 10^-8 cm^-3, and γ_br = 5.31 × 10⁴. The three different families of solutions, which can be distinguished in the range between 10¹¹ and 10¹⁴ Hz, correspond to α₁ = 1.6, 1.8, and 2.0, as discussed in Sect. 3. The infrared and visible data can be reproduced by taking into account the host-galaxy contribution.