Supernova double-peaked light curves from double-nickel distribution

MARIANA ORELLANA; BERSTEN, MELINA C.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2022

0004-6361

Between the supernovae (SNe) of different luminosities, many double-peaked light curves (LCs) have been observed, depicting alarge morphological variety. Here we investigate which of them can be modeled by assuming a double-peaked distribution of theradioactive material, as originally proposed for SN2005bf. The inner zone corresponds to the regular explosive nucleosynthesis andextends outwards with the usual meaning of mixing. The outer 56 Ni–rich shell can be related to the effect of jet-like outflows thatinteracted with more distant portions of the star before the arrival of the SN shock. As the outer layer is covered by optically less thickmatter, its energy emerges earlier and generates a first peak of radiation. To investigate this scenario in more detail we have appliedour hydrodynamic code that follows the shock propagation through the progenitor star and takes into account the effect of the γ-rayphotons produced by the decay of the radioactive isotopes. We present a simple parametric model for the 56 Ni abundance profile andexplore the consequences on the LC of individually varying the quantities that define this distribution, making focus into the stripped-envelope progenitors. In this first study we are interested into the applicability of this model to SNe that have not been classified assuperluminous, so we have selected our parameter space accordingly. Then, within the same mathematical prescription for the 56 Ni-profile, we revisit the modeling of a set of objects, SN2005bf, PTF2011mnb, SN2019cad, SN2008D, for which this idea have beenapplied before. In some cases, a decrease of the gamma-ray opacity is required in order to fit the late time observations. Thenwe discuss in which other cases this scenario is likely or not to explain the LC morphology. A steep initial decline in the observedbolometric LC at less than few days after the explosion becomes less feasible for this model, because it requires a large abundanceof 56 Ni near the stellar surface, meaning a strongly inverted distribution. An initial bolometric rise before the two peaks seems morefavorable for the double nickel case and can be difficult to explain by other scenarios unless they invoke a combination of power