Variation in spectral parameters of RX J0440.9+4431 w.r.t outburst source luminosity in 1–120 keV  of the giant outburst. An absorbed cutoff power-law model (i.e. cutoffpl) with additional components like: 1) a Gaussian component at 6.4 keV , 2) a cyclotron absorption component at 35-40 keV , 3) a soft blackbody component near 0.3 keV , and sometimes a second blackbody component near 2.5 keV  has been used to obtain the best-fitted continuum model.