Author(s): , , , ,
Institution(s): 1. Max Planck Institute for Extraterrestrial Physics, 2. Thüringer Landessternwarte Tautenburg, 3. Universidad Andres Bello
The connection between supernovae (SNe) and gamma-ray bursts (GRBs) have become more and more interesting over the years. For theoreticians, these events have posed as the perfect laboratory to study the core collapse of massive stars. While the GRB emission signals the activity of the central engine, the radiation from the SN reveals the properties of the outer envelope. For us observers, the challenge remains to characterize these fleeting events as deeply as possible in a broad wavelength range. Observable quantities such as luminosity evolution, spectral shape, and expansion velocity are crucial to derive the intrinsic dust extinction and the physical parameters of the SN explosion (nickel mass, ejecta mass, and kinetic energy). In the last few years the sample size of GRB-SN associations has nearly doubled, which enables us tackling the key questions in the field using a statistical approach. Moreover, different scenarios such as the collapsar model and the magnetar-driven explosion have been tested. GRBs have been linked to luminous type-Ic SNe, however, never as bright as super-luminous (SL) SNe. Recently, a remarkable object halfway between GRB-SNe and SL-SNe in terms of luminosity has been discovered. It has been claimed that a newly-formed magnetar has driven both the GRB and the SN counterparts. The nickel mass computed from the SN peak bolometric luminosity lies more that 3σ higher than the GRB-SN normal distribution characterized by 0.40 ± 0.15 M⊙. Along with additional observational evidence, this indicates that the SN explosion could not have been solely powered by cobalt and nickel decay. The modeling of the spectrum and the light curve requires a magnetar with an initial spin period of 12 ms and a magnetic field strength of (6–9)×1014 G. There are authors that even claim that all GRB-SNe are powered by magnetars. In this talk, I will review important aspects of the GRB-SN connection (observations and theory), present results on magnetar-driven explosions of GRB-SNe, show the statistical analyses of the full GRB-SN sample, and compare the properties of the most recent and unusual events.