Log-parabola photon index, α, versus 3–7 keV and 7–30 keV flux as measured by NuSTAR during the third IXPE observation (IXPE 3 period). The data are 1 h binned and α is obtained by fitting a log-parabola function that has a fixed curvature parameter β = 0.45. The gray arrows show the direction of time, and the blue and red arrows in the middle of the panels depict the clockwise and counterclockwise directions observed in the data, respectively.