The full evolution of supernova remnants in low- and high-density ambient media

Abstract

ABSTRACT Supernova explosions and their remnants (SNRs) drive important feedback mechanisms that impact considerably the galaxies that host them. Then, the knowledge of the SNRs evolution is of paramount importance in the understanding of the structure of the interstellar medium and the formation and evolution of galaxies. Here, we study the evolution of SNRs in homogeneous ambient media from the initial, ejecta-dominated phase, to the final, momentum-dominated stage. The numerical model is based on the Thin-Shell approximation and takes into account the configuration of the ejected gas and radiative cooling. It accurately reproduces well-known analytic and numerical results and allows one to study the SNR evolution in ambient media with a wide range of densities n0. It is shown that in the high-density cases, strong radiative cooling alters noticeably the shock dynamics and inhibits the Sedov-Taylor stage, thus limiting significantly the feedback that SNRs provide to such environments. For n0 > 5 × 105 cm−3, the reverse shock does not reach the centre of the explosion due to the rapid fall of the thermal pressure in the shocked gas caused by strong radiative cooling.