Emission measure as a function of temperature for the eight-temperature model fit to HETG (HEG and MEG fitted simultaneously) and LETG spectra (histograms), together with the emission measures and temperatures from isothermal model fits (large round symbols). The emission measures are in units of ﹩{10}^{-14}/4\pi {D}^{2}﹩ cm⁻³, where D is the distance to the source. The shaded and hatched regions indicate the 1σ uncertainties at each temperature for HETG and LETG fits, respectively; 1σ upper limits on the multithermal histogram emission measures are indicated by downward-pointing arrows for temperature components that are not significantly present in the data. Error bars on the isothermal model fits are smaller than the symbols, except for that shown.