Residuals (data−model) of fitting of the thermonuclear X-ray burst spectra (of 2 s time durations) observed from IGR J17591–2342 with AstroSat/LAXPC (see Section 4.3). Three spectra for 8 − 10 s (panels a1, a2), 26 − 28 s (panels b1, b2), and 28 − 30 s (panels c1, c2) since the burst onset are considered. These are times during the blackbody radius peaks. Left panels (a1, b1, c1) are for the XSPEC spectral model tbabs(edge*bbodyrad+constant*powerlaw), and right panels (a2, b2, c2) are for the model tbabs(bbodyrad+constant*powerlaw+gauss+gauss) (the second Gaussian in ∼12 − 20 keV is included if required). This figure shows that during the radius peaks, the model including Gaussian(s) fits the burst spectra better than the model including an edge does.