Simulating the Source Parameter Recovery Capability from Coronal X-ray Spectra: the Sax/lecs and the Asca/sis Cases

We have studied the performance of global 2 tting applied to low-resolution X-ray spectroscopy, focusing on the retrieval of source parameters , with emphasis on the coronal metallicity. The study has been conducted by tting large numbers of simulated spectra with known characteristics , and studying the distribution of the best-t parameters, using the responses of the LECS detector onboard the SAX satellite and of the SIS detector onboard the ASCA satellite. The simulations have been done under the hypothesis that the intrinsic source spectrum can be described by two discrete temperatures. The performance of the tting process has been studied both in the case in which just the global metallicity is left free to vary and in the case in which the abundance of each element is independently left free to vary in the t process.