Chandra X-ray imaging spectroscopy of the young supernova remnant Kesteven 75.
HELFAND D.J., COLLINS B.F. and GOTTHELF E.V.
Abstract (from CDS):
We present a spatially resolved spectroscopic analysis of the young Galactic supernova remnant Kes 75 (SNR G29.7-0.3) using the Chandra X-Ray Observatory. Kes 75 is one of an increasing number of examples of a shell-type remnant with a central pulsar powering an extended radio/X-ray core. We are able to pinpoint the location of the recently discovered pulsar, PSR J1846-0258, and confirm that X-rays from the remnant's core component are consistent with nonthermal power-law emission from both the pulsar and its surrounding wind nebula. We find that the spectrum of the pulsar is significantly harder than that of the wind nebula. Fainter diffuse emission is detected from throughout the volume delineated by the radio shell with a surface brightness distribution strikingly similar to the radio emission. The presence of strong lines attributable to ionized Mg, Si, and S indicates that at least some of this emission is thermal in nature. However, when we characterize the emission using a model of an underionized plasma with nonsolar elemental abundances, we find that we require an additional diffuse high-energy component. We show that a significant fraction of this emission is an X-ray scattering halo from the pulsar and its wind nebula, although a nonthermal contribution from electrons accelerated in the shock cannot be excluded.