The Nickel Mass Distribution of Normal Type II Supernovae

Abstract

Core-collapse supernova explosions expose the structure and environment of massive stars at the moment of their death. We use the global fitting technique of Pejcha & Prieto (2015a,b) to estimate a set of physical parameters of 19 normal Type II SNe, such as their distance moduli, reddenings, 56 Ni masses M Ni , and explosion energies E exp from multicolor light curves and photospheric velocity curves. We confirm and characterize known correlations between M Ni and bolometric luminosity at 50 days after the explosion, and between M Ni and E exp . We pay special attention to the observed distribution of M Ni coming from a joint sample of 38 Type II SNe, which can be described as a skewed-Gaussian-like distribution between 0.005 M ⊙ and 0.280 M ⊙ , with a median of 0.031 M ⊙ , mean of 0.046 M ⊙ , standard deviation of 0.048 M ⊙ and skewness of 3.050. We use twosample Kolmogorov-Smirnov test and two-sample Anderson-Darling test to compare the observed distribution of M Ni to results from theoretical hydrodynamical codes of core-collapse explosions with the neutrino mechanism presented in the literature. Our results show that the theoretical distributions obtained from the codes tested in this work, KEPLER and Prometheus Hot Bubble, are compatible with the observations irrespective of different pre-supernova calibrations and different maximum mass of the progenitors.

Excavating the Explosion and Progenitor Properties of Type IIP Supernovae via Modeling of their Optical Light Curves

“…The systematic errors in our estimations are difficult to quantify, given that they may depend on factors in the stellar evolution, the explosion mechanism, or the mixing. A larger sample size of SNe might perhaps provide a stronger correlation, but given that all eight of our SNe fall above both Müller et al (2017) relations, this seems unlikely. M18 show how the explosion energy can vary depending on the degree of 56 Ni mixing.…”

“…Pejcha & Prieto (2015) show that there is an inherent degeneracy between 56 Ni mass and explosion energy that makes the correlation weak. It is clear from Figure 3 in Müller et al (2017) that although there may be a correlation between the 56 Ni mass and explosion energy, the scatter in the values is large. 2014cx Figure 16.…”

PUSHing Core-collapse Supernovae to Explosions in Spherical Symmetry. IV. Explodability, Remnant Properties, and Nucleosynthesis Yields of Low-metallicity Stars*

“…In the top panel of Figure 13 we show the explodability for the progenitors in our sample in comparison with ob- served explosion energies (black crosses). The observational data shown are the same as in Paper II, complemented with the sample of Müller et al (2017). Note that the observed supernovae are in the local Universe (redshift z < 0.01).…”

“…; the labels "a" and "b" denote the two different energy determinations given in Müller et al (2017)). The lines are the corresponding fits to the data given in Müller et al (2017).…”

KSP-SN-2016kf: A Long-rising H-rich Type II Supernova with Unusually High 56Ni Mass Discovered in the KMTNet Supernova Program

“…KSP-SN-2016kf appears to have the most luminous plateau among the shown sample of Type II SNe as well as one of the highest inferred 56 Ni masses, while it still follows the known correlation. The 56 Ni mass of Type II SNe has also been known to be correlated with the explosion energy (Hamuy 2003;Pejcha & Thompson 2015;Müller et al 2017), and the 56 Ni mass of ∼ 0.1 M and 1.3 foe explosion energy of KSP-SN-2016kf appear to follow the correlations in those studies. Figure 12 shows the V -band light curves of a sample of Type II SNe presented in Anderson et al (2014) in comparison with that of KSP-SN-2016kf.…”