What makes the dead rise (or, what powers the light curves of the most luminous supernovae?)

by Priscila Pessi

Friday 26 Apr 2024, 16:00 → 17:30 Europe/Stockholm

Albano 3: 6203 - Floor 6 Large Lunch Room (44 seats) (Albano Building 3)

Supernovae result from the explosive death of massive stars. If the progenitor star retained at least some of its outermost hydrogen layers before explosion, the spectra of the supernova will show hydrogen lines. These supernovae are classified as Type II. Through the spectral evolution of a Type II supernova, we can infer the structure of the progenitor star. The light curve, produced by the supernova’s brightness variation over time, helps us understand the energetics of the explosion. Typical theoretical models propose that Type II supernova light curves are powered by hydrogen recombination and heating from radioactive decay of Nickel-56. However, there exist some atypical Type II supernovae whose spectral and light curve characteristics can not be explained by such a model alone, suggesting the need for alternative power sources. In this talk I will present Type II supernovae (SNe II) that show atypically bright light curves, classified as “LSNe II” and “SLSNe II”. I will explain why we keep adding letters at the beginning of the SN II name, and I will show which observables can help elucidate the physical mechanism that powers these events.