6533b82ffe1ef96bd1295da3
RESEARCH PRODUCT
Spatial identification of the overionized plasma in W49B
Jean BalletMarco MiceliMarco MiceliFabio RealeFabio RealeA. DecourchelleFabrizio Bocchinosubject
High Energy Astrophysical Phenomena (astro-ph.HE)PhysicsHardness ratioAstrophysics::High Energy Astrophysical PhenomenaInterstellar cloudFOS: Physical sciencesAstronomy and AstrophysicsAstrophysicsPlasmaX-rays: ISM ISM: supernova remnants ISM: individual object: W49BSettore FIS/05 - Astronomia E AstrofisicaSpace and Planetary ScienceSpontaneous emissionSpectral analysisSpatial localizationAstrophysics - High Energy Astrophysical PhenomenaEjectaSupernova remnantISM ISM: supernova remnants ISM: individual object: W49B [X-rays]Astrophysics::Galaxy Astrophysicsdescription
Recent Suzaku X-ray observations of the ejecta-dominated supernova remnant W49B have shown that in the global spectrum there is a clear indication for the presence of overionized plasma whose physical origin is still under debate. In order to ascertain the physical origin of such a rapidly cooling plasma, we focus on the study of its spatial localization within the X-ray emitting ejecta. We confirm the presence of a saw-edged excess (interpreted as a strong radiative recombination continuum) in the global spectrum above 8 keV, emerging above the ionization-equilibrium model. We produce a hardness ratio map to determine where the plasma is overionized and we perform a spectral analysis of the regions with and without strong overionization. We find that the overionized plasma is localized in the center of the remnant and in its western jet, while it is not detected in the bright eastern jet, where the expansion of the ejecta is hampered by their interaction with a dense interstellar cloud. The location of overionized plasma suggests that the inner ejecta are rapidly cooling by expansion, unlike the outer ejecta, for which expansion is hampered by interstellar clouds seen in H2
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2010-05-01 |