The Plasma Structure of the Cygnus Loop from the Northeastern Rim to the Southwestern Rim

摘要: The Cygnus Loop was observed from the northeast to southwest with XMM-Newton. We divided region into two parts, north and south path, studied X-ray spectra along two. can be well fitted either by a one-component nonequilibrium ionization (NEI) model or two-component NEI model. rim regions relatively low kTe whose metal abundances are subsolar (0.1-0.2 Z☉). major part of paths requires Because projection effects, we conclude that low-kTe (~0.2 keV) component surrounds high-kTe (~0.6 component, latter having high (~5 times solar). Since is thought have originated in cavity explosion, thus originates wall, while ejecta. flux cavity-wall shows large variation our paths. find it very thin region, suggesting blowout line sight. distribution inside ejecta exhibits nonuniformity, depending on element: O, Ne, Mg more abundant outer Si, S, Fe concentrated inner all metals showing strong asymmetry. This observational evidence implies an asymmetric explosion progenitor star. abundance also indicates mass about 15 M☉.