Speaker
Description
Superluminous supernovae (SLSNe) are extraordinary stellar explosions that dwarf normal supernovae (SNe). Their extreme luminosity and (in most cases) longevity requires an energy budget that far exceeds that of normal SNe and power sources. So-called SLSNe II are H-rich, broad-lined events that show signs of interaction with their circumstellar medium (CSM) despite the lack of strong narrow emission lines; but in the most luminous cases this interaction is not enough to fully power these SNe, and a central engine seems necessary to explain them. Here I examine the properties of the CSM in the literature sample of SLSNe II through various methods, including studying the mass-loss rates through interaction signatures in the UV and signs of asymmetry in late-time spectra. I will summarize the similarities and differences in CSM between those SLSNe II that require a central engine and those that may be the high-luminosity end of the normal (interacting) SN distribution; with implications on their respective progenitor stars and their final evolutionary stages.