a) The radial surface brightness profiles of the NE (squares) and SW (circles) halves in the 4–6 keV band, with the simulated PSF at 4.51 keV (dotted line); b) same as a) but in the 6–7 keV band, with the similated PSF at 6.4 keV (dotted line); c) The (6–7 keV)/(4–6 keV) ratio image of the nuclear region of Mrk 273, overlaid by the NICMOS H-band image contours showing the N and SW nuclei. The contours are drawn at five logarithmic intervals with the lowest level at 20% intensity of the peak brightness at the centre of the SW nucleus. The orientation of the image is north up, east to the left. The scale bar indicates 1 arcsec. This map shows a trend of a 6–7 keV band enhancement towards NE.