On the Intrinsic Diversity of Type Ii-Plateau Supernovae

Abstract

Hydrogen-rich Type II-Plateau supernovae exhibit correlations between the plateau luminosity L pl , the nickel mass M Ni , the explosion energy E exp , and the ejecta mass M ej . Using our global, self-consistent, multi-band model of nearby well-observed supernovae, we find that the covariances of these quantities are strong and that the confidence ellipsoids are oriented in the direction of the correlations, which reduces their significance. By proper treatment of the covariance matrix of the model, we discover a significant intrinsic width to the correlations between L pl , E exp and M Ni , where the uncertainties due to the distance and the extinction dominate. For fixed E exp , the spread in M Ni is about 0.25 dex, which we attribute to the differences in the progenitor internal structure. We argue that the effects of incomplete γ-ray trapping are not important in our sample. Similarly, the physics of the Type II-Plateau supernova light curves leads to inherently degenerate estimates of E exp and M ej , which makes their observed correlation weak. Ignoring the covariances of supernova parameters or the intrinsic width of the correlations causes significant biases in the slopes of the fitted relations. Our results imply that Type II-Plateau supernova explosions are not described by a single physical parameter or a simple one-dimensional trajectory through the parameter space, but instead reflect the diversity of the core and surface properties of their progenitors. We discuss the implications for the physics of the explosion mechanism and possible future observational constraints.

Nucleosynthesis in Asymmetric, Core-Collapse Supernovae of Massive Stars

“…These under-estimates are possibly caused from poor estimate of reaction rates of 40 Ca(α, γ) 44 Ti and 44 Ti(α, p) 47 V. When we adopt an upper bound of the rate of 40 Ca(α, γ) 44 Ti and lower bound of 44 Ti(α, p) 47 V estimated in [6], instead of our standard rates in REACLIB, we find that M ( 44 Ti) increase by a factor of 2-3 and that estimated M ( 44 Ti) is comparable to SN1987A for the 25.0M ⊙ progenitor. Finally, we compare our results with the correlation of log M ( 56 Ni) to log E exp observed in Type II-Plateau SNe [7]. We find that the observed correlation (dashed line in lower right panel of Fig.…”

A Radio Continuum and Polarization Study of SNR G57.2+0.8 Associated with Magnetar SGR 1935+2154

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LINE IDENTIFICATIONS OF TYPE I SUPERNOVAE: ON THE DETECTION OF Si II FOR THESE HYDROGEN-POOR EVENTS

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