G-ratio (left) and Ο VII-to-O VIII emission line ratio (right) as a function of plasma temperature. The black solid and dashed horizontal lines show the best fit and 1σ uncertainty on the G-ratio measured by fitting the lines of the O VII triplet from the e12 spectrum. The black filled dots and connecting line show the expected relation between the G-ratio and temperature, expected for collisionally ionized plasma in thermal equilibrium (obtained from the APEC model in Xspec). The measurement of the G-ratio implies that the temperature must be kT > 0.06 keV, if produced by a single plasma component in thermal equilibrium. The red solid and dashed horizontal line shows the best fit and 1σ uncertainty on the Ο VIII-to-O VII line ratio measured by fitting the e12 spectrum. The red filled dots and connecting line show the expected relation between Ο VIII-to-O VII line ratio and temperature, expected for collisionally ionized plasma in thermal equilibrium (obtained from the APEC model in Xspec). Under the assumption that a single optically thin and collisionally ionized component is producing both lines, the observed line ratio implies that the temperature must be within the range 0.152 < kT < 0.160 keV. The two completely independent estimates of the temperature are in agreement with each other, suggesting that the same plasma might produce the bulk of the O VII and Ο VIII emission.