The Effect of Circumstellar Matter on the Double-peaked Type Ic Supernovae and Implications for LSQ14efd, iPTF15dtg, and SN 2020bvc

Double-peaked light curves are observed for some Type Ic supernovae (SNe Ic), including LSQ14efd, iPTF15dtg, and SN 2020bvc. One possible explanation of the first peak would be shock-cooling emission from massive extended material around the progenitor, which is produced by mass eruption or rapid expansion of the outermost layers of the progenitor shortly before the supernova explosion. We investigate the effects of such circumstellar matter (CSM) on the multiband optical light curves of SNe Ic using the radiation hydrodynamics code STELLA. Two different SNe Ic progenitor masses at the pre-SN stage (3.93 M-circle dot and 8.26 M-circle dot) are considered in the SN models. The adopted parameter space consists of the CSM mass of M-CSM = 0.05-0.3M(circle dot), the CSM radius of R-CSM =10(13)-10(15) cm, and the explosion energy of E-burst = (1.0-12.0) x 10(51) erg. We also investigate the effects of the radioactive nickel distribution on the overall shape of the light curve and the color evolution. Comparison of our SN models with the double-peaked SNe Ic LSQ14efd, iPTF15dtg, and SN 2020bvc indicates that these three SNe Ic had a similar CSM structure (i.e., M-CSM approximate to 0.1-0.2M(circle dot) and R-CSM =10(13)-10(14) cm), which might imply a common mechanism for their CSM formation. The implied mass-loss rate of (M) over dot greater than or similar to 1.0 M-circle dot yr(-1) is too high to be explained by the previously suggested scenarios for pre-SN eruption, which calls for a novel mechanism.

Automated summary

Analysis of double-peaked light curves in Type Ic supernovae suggests similar circumstellar matter structures, implying a common mechanism for their formation. The implied high mass-loss rate cannot be explained by previously suggested scenarios, calling for a novel mechanism.