Simulated X-ray emission for a runaway model of Kepler's supernova remnant

We present two-dimensional numerical simulations of a model for Kepler's supernova remnant (SNR) carried out with the YGUAZU-A code. Following previous studies, we have assumed that the peculiar shape of this young remnant arises as a consequence of the interaction of the SNR blast wave with the bow shock formed by the wind of its high velocity progenitor. Furthermore, from our numerical results we have obtained synthetic X-ray emission maps, which can be directly compared with recent and previous observations of this SNR. Our models show that a nice fit with respect to the X-ray morphology and luminosity is obtained for a SN progenitor with mass-loss rate of 5 x 10(-5) M-circle dot yr(-1), an ambient medium density of 10(-2) cm(-3), an initial explosion energy of 8 x 10(50) ergs, and a total ejected mass within 1.4-2.5 M-circle dot. In our simulations, parameters typical of a young population progenitor have not been considered. This model also predicts a similar to 0.3% yearly decrease in the total X-ray luminosity, which is consistent with observed values. The parameters employed in our runs correspond to a Type Ia supernova. Based on our simulations, we find that the expansion rate increases after the SNR blast wave overruns the bow shock, and we discuss whether this can explain the observed difference between the expansion rates measured from sequences of radio and X-ray images.