Ev. Gotthelf et G. Vasisht, KES-73 - A YOUNG SUPERNOVA REMNANT WITH AN X-RAY-BRIGHT, RADIO-QUIET CENTRAL SOURCE, The Astrophysical journal, 486(2), 1997, pp. 133
We clarify the nature of the small-diameter supernova remnant (SNR) Ke
s 73 and its central compact source, 1E 1841-045, using X-ray data acq
uired with ASCA. We introduce a spatiospectral decomposition technique
necessary to disentangle the ASCA spectrum of the compact source from
the barely resolved shell-type remnant. The source spectrum (1-8 keV)
is characterized by an absorbed power law with a photon index alpha 0
similar or equal to 3.4 and N-H similar or equal to 3.0 x 10(22) cm(-
2), possibly nonthermal in nature. This bright X-ray source is likely
a slowly spinning pulsar, whose detection is reported in our companion
paper. The SNR spectrum is characteristic of a thermal plasma, with k
T similar or equal to 0.6 keV and emission lines typical of a young re
mnant. The element Mg and possibly O and Ne are found to be overabunda
nt, qualitatively suggesting an origin from a massive progenitor. We f
ind that Kes 73 is a young (less than or similar to 2000 yr) Type II/I
b SNR containing a neutron star pulsar spinning anomalously slowly for
its age. Kes 73 is yet another member of a growing class of SNRs cont
aining radio-quiet compact sources with a hard spectral signature.