Fitting with previous model

I'm starting with GX5-1 as I have some prior experience with the source.  In fact, I published a paper on the dust-scattered halo around GX5-1 in 2006, with the unassuming title "THE X-RAY HALO OF GX 5-1."  That paper used RXTE but in a pointed mode, allowing a good measurement of the X-ray spectrum.  I decided to compare that fit to the current HETG data; see image for the result.  Pretty clearly, the fit is decent -- especially since it was done on an observation done 5+ years before this one.  This suggests that the poor fit at high and low energies might well be due to problems with the HETG calibration (not surprising given how bright GX5-1 is), rather than a model failure.  However, we need to remember that RXTE has little or not response below 2 keV, so it's possible that RXTE simply didn't see the low-energy emission.  However, RXTE is quite good at high energies, so the poor fit there is likely due to HETG issues.