Core-collapse (CC) supernova remnants (SNRs) are the nebular leftovers of defunct massive stars
that 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, as well as the intrinsic properties of the explosion
and those of the ambient medium. By means of 2.5-dimensional (2.5D) numerical magneto-hydrodynamic (MHD) simulations, we modelled
the long-term evolution of SNRs generated by runaway rotating massive
stars moving into a magnetised interstellar medium (ISM).
Radiative transfer calculations reveal that the projected non-thermal emission of
SNRs decreases over time, namely: older remnants are fainter than younger
ones. Older ($80\ kyr$) SNRs whose progenitors were moving with a space velocity corresponding to a Mach number of $M=1$ ($v_ km\ $) in the
Galactic plane of the interstellar medium ($n_ ISM $) are brighter in synchrotron
than when moving with a Mach number of $M=2$ ($v_ km\ $).
We show that runaway red supergiant progenitors first induce
an asymmetric non-thermal $1.4\ GHz$ barrel-like synchrotron SNRs (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 SNRs are currently in this bilateral-to-Cygnus loop evolutionary sequence. Therefore, this population should be taken into account with repect to interpreting the data as part of the forthcoming Cherenkov Telescope Array (CTA) observatory.