부산대학교 도서관

Core-collapse supernova remnants are the nebular leftover of defunct massive stars which have died during a supernova explosion, mostly while undergoing the red supergiant phase of their evolution. The morphology and emission properties of those remnants are a function of the distribution of circumstellar material at the moment of the supernova, the intrisic properties of the explosion, as well as those of the ambient medium. By means of 2.5 dimensional numerical magnetohydrodynamics simulations, we model the long term evolution of supernova remnants generated by runaway rotating massive stars moving into a magnetised interstellar medium. Radiative transfer calculations reveal that the projected non-thermal emission of the supernova remnants decreases with time, i.e. older remnants are fainter than younger ones. Older (80 kyr) supernova remnants whose progenitors were moving with space velocity corresponding to a Mach number M = 1 (v_star = 20 km/s ) in the Galactic plane of the ISM (nISM = 1/cm3 ) are brighter in synchrotron than when moving with a Mach number M = 2 (v_star = 40 km/s ). We show that runaway red supergiant progenitors first induce an asymmetric non thermal 1.4 GHz barrel like synchrotron supernova remnants (at the age of about 8 kyr), before further evolving to adopt a Cygnus loop like shape (at about 80 kyr). It is conjectured that a significative fraction of supernova remnants are currently in this bilateral-to-Cygnus-loop evolutionary sequence, and that this should be taken into account in the data interpretation of the forthcoming Cherenkov Telescope Array (CTA) observatory.
Comment: Accepted at Astronomie and Astrophysics