Pulse profiles in different energy bands for both NICER in blue and NuSTAR in red. The left plot shows the first NuSTAR observation and the concurrent NICER pointing, while the right plot shows the second NuSTAR observation and its concurrent NICER pointing. The hardness ratio in the lowest panel is calculated from NuSTAR data as (H + S)/(H − S), with the two energy bands S: 3−5 keV and H: 20−40 keV.