Supernova progenitor stars in the initial range of 23 to 33 solar masses and their relation with the SNR Cassiopeia A

Abstract

Multi wavelength observations of Cassiopeia A (Cas A) have provided us with a strong evidence for the presence of circumstellar material surrounding the progenitor star. It has been suggested that its progenitor was a massive star with a strong mass loss. But, despite the large amount of observational data from optical, IR, radio and x-ray observations, the identity of Cas A progenitor is still elusive. In this work, we compute stellar and circumstellar numerical models to look for the progenitor of Cas A. The models will be compared with the observational constraints. We have computed stellar evolution models to get time-dependent wind parameters and surface abundances. We have chosen a set of probable progenitor stars, with initial masses of 23, 28, 29, 30 and 33 \Mo, with mass loss. The derived mass loss rates and wind terminal velocities are used to simulate the evolution of the circumstellar medium. Our stellar set gives distinct SN progenitors: RSG, luminous blue super giants (LBSGs) and Wolf-Rayet (WR) stars. The 23 \Mo star explodes as a RSG in a $\rm \rho \sim r^{-2}$ dense, free streaming wind surrounded by a thin, compressed, RSG shell. The 28 $\Mo$ star explodes as a LBSG, and the SN blast wave interacts with a low density, free streaming wind surrounded by an unstable and massive ''RSG+LBSG'' shell. Finally, the 30 and 33 \Mo stars explode as WR stars surrounded by fast, WR winds that terminate in highly fragmented ''WR+RSG shell''. We have compared the surface chemical abundances of our stellar models with the observational abundances in Cas A. The abundance analysis shows that the progenitor was a star with an initial mass of the order of 30 \Mo, while the hydrodynamical analysis favors progenitors of initial masses around 23.