Spatial variations of spectral properties over the hard-band diffuse emission. Left: Surface brightness (upper panel) in units of 10 −15 erg s −1 cm −2 arcsec −2 and energy index of power-law continuum (lower panel) in the 4-6 keV band; Middle: Surface brightness of 6.67 keV Fe xxv emission in units of 10 −9 ph cm −2 s −1 arcsec −2 and line EW in units of keV; and Right: Surface brightness and line EW of 6.4 keV cold Fe K emission in the same units as the Fe xxv emission.

Contexts in source publication

Context 1

... on the above fits, we constructed surface brightness maps of the 4-6 keV continuum, cold Fe and Fe xxv emission over the 38 region segments, as shown in Fig. 4. The maps of 4-6 keV continuum slope and equivalent width (EW) of the two Fe lines are also shown. The same values given in the maps with the 68% error intervals are plotted in the order of the segment number in Fig. 5. A few spectra with a 4-6 keV slope close to zero indicate that they might be more absorbed than the rest since they ...

Context 2

... above observation regarding the north-south brightness symmetry and asymmetry is also illustrated by a comparison of cumulative distribution functions (CDFs) of surface brightness of those quantities (Fig. 6). The diffuse continuum emission has the lowest surface brightness at the north-eastern outskirt (see Fig. 4). On applying the surface brightness cut of > 0.06 × 10 −15 erg s −1 cm −2 arcsec −2 , the area of the faintest emission is discarded, leaving 17/12 segments (out of 22/14 segments) on the northern/southern sides. The segments dX34 and dX35 located in the disc plane were not considered. The median values of the brightness of the ...

Context 3

... line detection at the confidence level of > 95% is found to occur when line intensity exceeds 1 × 10 −7 ph cm −2 s −1 . There are 15 segments showing this relatively strong Fe xxv detection and most of them are located on the northern side ( Fig. 5) and connected to each other (Fig. 4), suggesting a continuous distribution. Unmatched continuum and line brightness distributions naturally lead to a non-uniform EW ...

Context 4

... Fe xxv EW map in Fig. 4 shows an excess morphology similar to that of the surface brightness but extends further to larger radii in both northern and southern directions. Curiously, these extensions appear to originate from a particular region in the disc. These excesses show EW ranging from 0.2 keV to 0.6 keV and includes dX37 which shows an exceptionally ...

Context 5

... On inspecting those projected profiles, the brightness peak can be located at around the reference point. The light distribution along the major axis is relatively flat and skewed towards the east (Fig. 10a). Along the minor axis, the light distribution is nearly symmetric at the brighter inner part, as already seen in the 4-6 keV map (Fig. 4), but shows an enhanced extension towards north at the fainter brightness level (Fig. 10b). Along each axis, the profile shapes of the two strips are found to be similar, as shown in the standardised brightness plots (Fig. 10c), while their absolute fluxes ...

Context 6

... given its small contribution to the continuum emission, the thermal emission from the hot gas of kT 5 keV is the source of the majority of Fe xxv line, as shown above, and can be traced by the enhanced Fe xxv EW (Fig. 4). The map shows that the presence of the hot gas component is limited within a small distance from the starburst disc and seen to be much stronger on the northern side, suggesting an asymmetric ejection of hot gas. A northern asymmetry in outflow structures have also been observed in other wavelengths. In the mid-infrared (mid-IR) image ...