Seminars at FGG

Luminous early-time CSM-interacting type II Supernovae

Speaker: Cosimo Inserra (Queen's University Belfast)

Date and time: 2012-05-08 10:00

Aim of this work in the observational study of the properties of type II SNe sample belonging to the bright end of the luminosity distribution. In particular, we studied objects that have been considered overall "normal" but with an unusual luminosity at early epochs. We did not concentrate to the single exceptional, peculiar or overluminous objects. Rather, we tried to understand the phenomena causing an increased luminosity in an overall scenario of "normality". The sample of five new objects (i.e. SNe 2007od, 2009bw, 2007pk, 2009dd and 2010aj), plus three found in the Padova-Asiago archive (i.e. SNe 1995ad and 1996W), has been analysed. Moreover, the most of these SNe have also shown clues of interaction with a close circumstellar matter (CSM) leading to imagine a scenario with interaction, weaker than that shown by type IIn, occurs at early phase. The present work highlights the weakness of the current classication scheme for CCSNe. The proliferation of types based only on the morphology of the light curves (IIP, IIL) or in the line profiles (IIn) does not correspond to a real differentiation between the physical processes at stake.