NuSTAR (blue circles: module A; red triangles: module B) spectra of J17407 during the low luminosity state between flares (blue circles in Fig. 3). Top panel: spectra are fitted with an absorbed power law with a high-energy cutoff. Middle panel: residuals of the same fit of the top panel. Bottom panel: residuals of the fit of the spectra with an absorbed power law. See Table 2 for the best-fit parameters.