Poster Presentation
A New Insight into Electron Acceleration Properties from Theoretical Modeling of Double-peaked Radio Light Curves in Core-collapse Supernovae
Presenter: Tomoki Matsuoka (Academia Sinica Institute of Astronomy and Astrophysics/ASIAA)
It is recognized that some core-collapse supernovae (SNe) show a double-peaked radio light curve within a few years since the explosion. A shell of circumstellar medium (CSM) detached from the SN progenitor has been considered to play a viable role in characterizing such a rebrightening of radio emission. Here, we propose another mechanism that can give rise to the double-peaked radio light curve in core-collapse SNe. The key ingredient in the present work is to expand the model for the evolution of the synchrotron spectral energy distribution (SED) to a generic form, including fast and slow cooling regimes, as guided by the widely accepted modeling scheme of gamma-ray burst afterglows. We show that even without introducing an additional CSM shell, the radio light curve would show a double-peaked morphology when the system becomes optically thin to synchrotron self-absorption at the observational frequency during the fast cooling regime. We can observe this double-peaked feature if the transition from the fast cooling to slow cooling regime occurs during the typical observational timescale of SNe. This situation is realized when the minimum Lorentz factor of injected electrons is initially large enough for the nonthermal electrons' SED to be discrete from the thermal distribution. We discuss the possible application of our model for SN 2007bg and other high-energy astrophysical phenomena such as fast radio bursts, from the perspective of the treatment of nonthermal electrons' SED.
asiaa.sinica.edu.tw