The γ-ray deposition histories of core-collapse supernovae

The γ-ray deposition history in an expanding supernova (SN) ejecta has been mostly used to constrain models for Type Ia SN. Here we expand this methodology to core-collapse SNe, including stripped envelope (SE; Type Ib/Ic/IIb) and Type IIP SNe. We construct bolometric light curves using photometry from the literature and we use the Katz integral to extract the γ-ray deposition history. We recover the tight range of γ-ray escape times, $t_0\approx 30\!-\!45\, \textrm {d}$ , for Type Ia SNe, and we find a new tight range $t_0\approx 80\!-\!140\, \textrm {d}$ , for SE SNe. Type IIP SNe are clearly separated from other SNe types with $t_0\gtrsim 400\, \textrm {d}$ , and there is a possible negative correlation between t₀ and the synthesized ⁵⁶Ni mass. We find that the typical masses of the synthesized ⁵⁶Ni in SE SNe are larger than those in Type IIP SNe, in agreement with the results of Kushnir. This disfavours progenitors with the same initial mass range for these explosions. We recover the observed values of ET, the time-weighted integrated luminosity from cooling emission, for Type IIP, and we find hints of non-zero ET values in some SE SNe. We apply a simple γ-ray radiation transfer code to calculate the γ-ray deposition histories of models from the literature, and we show that the observed histories are a powerful tool for constraining models.