Confidence contours are shown at the 68%, 90%, and 99% confidence levels, for LOS column density versus Γ parameters. The three colors represent the three NuSTAR observations: black for February 2013, red for January 2016, and green for August 2016. As all the models listed in Table B.1 are consistent with one another, only the fitting results from the UXCLUMPY model are shown here.