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Session 55 - Supernova Remnants.
Oral session, Tuesday, January 14
Harbour A,
CTB 80 amp; W50 are two `unusual' supernova remnants (SNRs) since unlike the other composite remnants, their radio morphology presents pronounced asymmetric structures. The `unusual' properties of these SNRs are to a large extent associated with the emission from the compact objects associated with them, and their X-ray emission is the key to a better understanding of their properties.
I intend to present the X-ray analysis of these two peculiar sources and their powering engines. CTB 80 contains a 40 millisecond isolated pulsar, PSR1951+32, emitting non-thermal X-rays, and powering a compact nebula which is resolved with the ROSAT HRI. It has also a synchrotron nebula extending few arcminutes east of the pulsar and overlapping the radio plateau. With the ROSAT PSPC, a large \leq 1^o emission region is also detected in the hard energy band. W50, long thought to be the largest galactic SNR, contains at its center the mini-AGN binary source SS433, famous for its two-sided jets. I will present the X-ray analysis of the eastern and western lobes of W50 with both the ROSAT PSPC as well as the ASCA GIS detectors, thus covering the 0.1 -- 10 keV energy range. The emission is elongated along the axis of the precession cone of the SS433 jets, with an enhancement of brightness at \sim 35^\prime from SS433. The X-ray emission out to the base of the radio `ears' is characterized by a hard spectrum whose spectral parameters vary in the radial and lateral directions. With the ROSAT PSPC, there is also detection of a much softer X-ray emission coincident with the eastern radio `ear' at the interaction zone between the jets and the ambient medium.
Using the above analysis and correlating the X-ray maps with those at other wavelengths, I discuss the possibility for these remnants to be partly or entirely produced by their powering engines, and derive some physical parameters relevant to better understand their nature.