Asymmetry study of the mixed-morphology supernova remnant G 18.95-1.1

Radio and X-ray maps of supernova remnants (SNRs) in many cases revealed an asymmetric global structure. This may reflect the inhomogeneity of the circumstellar/ambient matter, anisotropic energy release or both. Given a growing sample of the observed SNRs some techniques to characterize the global asymmetry are needed to identify old SNRs in sky surveys among other observed extended structures of low surface brightness. We discuss here the applications of modified power-ratio technique to quantify the global asymmetry of the mixed-morphology SNR G 18.95-1.1 using its recent mapping with SRG and compare results with the well-studied SNRs IC 443 and Cas A.