Systematic features of axisymmetric neutrino-driven core-collapse supernova models in multiple progenitors

Abstract

We present an overview of two-dimensional (2D) core-collapse supernova simulations employing neutrino transport scheme by the isotropic diffusion source approximation. We study 101 solar-metallicity, 247 ultra metal-poor, and 30 zero-metal progenitors covering zero-age main sequence mass from 10.8 M ⊙ to 75.0 M ⊙ . Using the 378 progenitors in total, we systematically investigate how the differences in the structures of these multiple progenitors impact the hydrodynamics evolution. By following a long-term evolution over 1.0 s after bounce, most of the computed models exhibit neutrino-driven revival of the stalled bounce shock at ∼ 200 -800 ms postbounce, leading to the possibility of explosion. Pushing the boundaries of expectations in previous one-dimensional (1D) studies, our results confirm that the compactness parameter ξ that characterizes the structure of the progenitors is also a key in 2D to diagnose the properties of neutrinodriven explosions. Models with high ξ undergo high ram pressure from the accreting matter onto the stalled shock, which affects the subsequent evolution of the shock expansion and the mass of the protoneutron star under the influence of neutrino-driven convection and the standing accretion-shock instability. We show that the accretion luminosity becomes higher for models with high ξ, which makes the growth rate of the diagnostic explosion energy higher and the synthesized nickel mass bigger. We find that these explosion characteristics tend to show a monotonic increase as a function of the compactness parameter ξ.

How to blow up a massive star

“…Hence a careful observational estimate of the true distribution of explosion energies is now required for a quantitative compari son. In line with longtime 2D simulations (Nakamura et al 2015, Bruenn et al 2016, they also find a weak trend for more mas sive progenitors to explode more energeti cally, which appears to be compatible with observations (Poznanski 2013).…”

“…3D simula tion can make firm predictions only for progenitors at the lowmass end, where Melson et al (2015b) pre dict an explosion energy of ~10 50 erg for a 9.6 M ⊙ pro genitor. Selfconsistent 2D simulations can be taken well beyond the first second (Mül ler 2015, Bruenn et al 2016) and are cheap enough to scan a wide range of progeni tor models (Nakamura 2015), but cannot be trusted to predict the energetics of the explosion correctly (Müller 2015).…”

A simple approach to the supernova progenitor–explosion connection

“…Except for the least massive supernova progenitors (Kitaura et al 2006;Müller et al 2012b), successful first-principle simulations of supernova explosions (Buras et al 2006;Marek & Janka 2009;Müller et al 2012aMüller et al ,b, 2013Janka et al 2012;Bruenn et al 2013Bruenn et al , 2016Suwa et al 2010;Nakamura et al 2015;Takiwaki et al 2012Takiwaki et al , 2014Summa et al 2015;O'Connor & Couch 2015) consistently show the persistence of accretion downflows for many hundreds of milliseconds after shock revival -and in many cases to the very end of the simulations so that the final explosion parameters of the models cannot be determined yet. A more quantitative analysis of the mass fluxesṀ out andṀ acc in neutrinodriven outflows and cold accretion downflows in the long-time simulations of Müller (2015) revealed that the accretion through downflows completely outweighs the outflow rate for a long time,…”

Crucial Physical Dependencies of the Core-Collapse Supernova Mechanism

“…This behavior is the reverse of what might be expected if low compactness signaled greater explodability. Finally, the work of Nakamura et al (2015) suggests that though they see a weak correlation, it is not monotonic with compactness. In fact, many of their plots versus compactness resemble scatter plots.…”