Transfer from One Region to Another

In cases where there is strong emission from the extended source, as there can be for clusters of galaxies, the fitted parameters for the SPF component can be significantly over or under estimated. In such cases it can be helpful to fit a spectrum extracted from the lower surface brightness regions in the field. For clusters of galaxies an outer annulus in the FOV can serve this purpose. However, in this case, the fitted normalization must be scaled from the limited region to the full FOV, which can be done by the routine sppartial:

sppartial fullimage=ffov/mos1S001-fovimspdet.fits
fullspec=ffov/mos1S001-fovt.pi
regimage=annu/mos1S001-fovimspdet.fits
regspec=annu/mos1S001-fovt.pi
regnorm=0.03

where fullimage=ffov/mos1S003-sp-full.fits is the SPF image template for the full FOV, fullspec=ffov/mos1S003-obj-all.pi is the spectrum for the full FOV, regionimage=annu/mos1S003-sp-ann.fits is the SPF template image for the restricted region, regionspec=annu/mos1S003-obj-ann.pi is the spectrum for the restricted region, and rnorm=0.03 is the fitted SPF normalization for the restricted region. (Here I've assumed that the extraction from the full FOV has ended up in a subdirectory named ffov while the extraction from the partial FOV has ended up in a subdirectory named annu.) In the proton call use the fitted spectral index from the restricted region and the scaled value for the normalization.

Figure 27: Images of the model SPF background in detector coordinates (upper panel, the output of proton) and in sky coordinates (lower panel, output of rotdet2sky). Note that values are both negative and positive due to the method for creating the instrument maps. On average the values are positive and the count images are sparse requiring averaging on angular scales where the SPF values provide good information.