Notes. We present two cases modelled with two different statistics: CSTAT for the case where source and background are fitted simultaneously, and χ² for background subtracted analysis. In the second case we consider two background regions: a distant background marked with the green ellipse in the upper panel of Fig. 1, and a local background defined as an annulus between 6′′ − 18′′ around the 5′′ source region. In the first row we show the results obtained with a model consisting of thermal bremsstrahlung with Galactic absorption (tbabs) and the Fe Gaussian line only. The second row shows model parameters when three more Gaussian lines are added to account for S, Ar, and Ca emission. Both fits were done using CSTAT statistics. The third and fourth rows describe background subtracted analysis (using the local and distant backgrounds, respectively) performed on data grouped according to S/N = 3 using the χ² statistic.