Supernova SN 2008iz in M82 galaxy

Abstract

We report on multi-frequency Very Large Array (VLA) radio observations for an on-going monitoring campaign of supernova SN 2008iz in the nearby galaxy M82. We fit two light curve models to the data, a simple power-law model and a simplified Weiler model, yielding a decline index, β = -1.23±0.01 and -1.41±0.02, respectively. The late time radio light curve evolution shows a flux density enhancement at ~1000 and ~1700 days which are a factor of ~2 and ~4 higher than the surrounding flux, respectively. The flux density enhancement from day 1700 does not show signs of decline from results obtained so far. The enhancement is attributed to SN 2008iz expanding shock wave encounter with a clumpy dense circumstellar medium.

Keywords: Supernova, SN 2008iz, Radio continuum, M82 galaxy