8th HEAD Meeting, 8-11 September, 2004
Session 24 Supernova Remnants and the Interstellar Medium
Poster, Friday, September 10, 2004, 9:00am-10:00pm

## [24.16] Neon Light Illuminates the Shell of Another Former Star: Supernova Remnant 3C58

E.V. Gotthelf, D.J. Helfand, L. Newburgh (Columbia University)

Deep X-ray imaging spectroscopy of the bright pulsar wind nebula 3C58 reveals a Neon-rich thermal X-ray shell superimposed on the bright nonthermal pulsar wind nebula emission. Radially resolved spectra obtained with the XMM-Newton telescope are well-characterized by a power-law model with the addition of a soft thermal emission component in varying proportions. These fits reproduce the previously noted increase in the spectral index with radius attributed to synchrotron burn-off of high energy electrons. Most interestingly, a newly resolved thermal component is shown to map out a shell-like structure approximately 6' in diameter centered on the pulsar. The presence of a strong emission line corresponding to the Ne9 He-like transition requires an overabundance of ~3 \times [Ne/Ne\sun] using the Raymond-Smith plasma model. The best fit temperature kT ~0.23 keV is essentially independent of radius. The origin of the Neon emission supports a massive star progenitor and the shell mass and diameter provide interesting constraints on the evolution of this remnant which houses one of the youngest pulsars in the Galaxy.

Bulletin of the American Astronomical Society, 36 #3
© 2004. The American Astronomical Soceity.