Peering into the heart of the M82 starburst: Type II supernova remnants and a possible relic GRB?

M82 is considered the archetypal starburst galaxy and at a distance of ~3.6 Mpc is one of the closest examples of its kind. It therefore provides a unique opportunity to study a star-forming environment in detail and particularly the discrete products of star-formation such as supernova remnants (SNR) and HII regions. Supernovae and supernova remnants play an important role in the feedback of energy and material into the surrounding interstellar medium as evidenced in M82 by the galactic superwind driven by the numerous supernovae, SNR and massive stellar winds.Radio observations can be used to see into the core of the star-forming region in the centre of M82 as they are unaffected by the gas and dust associated with such an intense starburst environment. Since their discovery in the 1970s, radio observations have been used to study and monitor the evolution of the ~100 supernova remnants at the heart of this galaxy.We present multi-epoch millarcsecond resolution images of the most compact supernova remnants in M82, spanning 25 years of evolution. In particular, we will discuss one of the quintessential SNR 43.31+59.2 as well as the unusual object 41.95+57.5 and its potential as a GRB afterglow.