Abstract
We present the results of a study of the Galactic supernova remnants (SNRs) Cas A, SN 1006, Vela Jr., RCW 86 and RX J1713.7-3946, which are well-known members of the shell-type SNRs. They have limb-brightened morphology in both X-ray and radio bands. Using archival data from Chandra and XMM-Newton X-ray Observatories, we investigate the non-thermal X-ray emission of these SNRs by extracting the X-ray spectra from different regions across the remnants. In recent years, it has been shown that analysing an extended source with accurately modelled background is important, since it might be effective on spectral results. In accordance with this purpose, we concentrate upon the background modelling by investigating its spectral parameters. Hence, the results of modelled background spectrum of the south-western rim of SN 1006 is exemplified by using a combination of thermal and non-thermal emission models properly to the background components. Herewith, we studied the changes in spectral properties, such as roll-off frequency and photon index values throughout the remnants which require accurately modelled background spectrum to estimate the reliable values.