The Overarching Framework of Core-Collapse Supernova Explosions as Revealed by 3D Fornax Simulations (1909.04152v2)

Abstract: We have conducted nineteen state-of-the-art 3D core-collapse supernova simulations spanning a broad range of progenitor masses. This is the largest collection of sophisticated 3D supernova simulations ever performed. We have found that while the majority of these models explode, not all do, and that even models in the middle of the available progenitor mass range may be less explodable. This does not mean that those models for which we did not witness explosion would not explode in Nature, but that they are less prone to explosion than others. One consequence is that the "compactness" measure is not a metric for explodability. We find that lower-mass massive star progenitors likely experience lower-energy explosions, while the higher-mass massive stars likely experience higher-energy explosions. Moreover, most 3D explosions have a dominant dipole morphology, have a pinched, wasp-waist structure, and experience simultaneous accretion and explosion. We reproduce the general range of residual neutron-star masses inferred for the galactic neutron-star population. The most massive progenitor models, however, in particular vis `a vis explosion energy, need to be continued for longer physical times to asymptote to their final states. We find that while the majority of the inner ejecta have Y$_e = 0.5$, there is a substantial proton-rich tail. This result has important implications for the nucleosynthetic yields as a function of progenitor. Finally, we find that the non-exploding models eventually evolve into compact inner configurations that experience a quasi-periodic spiral SASI mode. We otherwise see little evidence of the SASI in the exploding models.

• The paper demonstrates that 3D simulations of 19 progenitor models reveal explodability is driven by complex mass profiles rather than compactness alone.
• It finds that explosion energy and morphology vary, with lower mass stars exploding earlier and higher mass stars showing delayed, more energetic dipole explosions.
• The study highlights the pivotal role of neutrino interactions in core-collapse dynamics and stresses the need for extended simulations to capture full asymptotic behavior.

Core-Collapse Supernova Explosions: Insights from 3D Simulations

The paper "The Overarching Framework of Core-Collapse Supernova Explosions as Revealed by 3D Simulations" offers a significant expansion on the current understanding of core-collapse supernovae (CCSN) through an extensive suite of 3D simulations. This work, conducted by Burrows et al., encompasses nineteen simulations across a variety of progenitor masses, considered the largest collection of 3D CCSN simulations to date, thus providing a comprehensive scope for analyzing the dynamics and outcomes of these celestial events.

Key Findings and Methodological Approaches

The paper identifies critical insights into the factors influencing CCSN explosions:

• Progenitor Mass and Explodability: The research underscores that explodability is not solely dictated by progenitor mass or compactness. Simulations reveal that stars with similar compactness parameters may exhibit divergent outcomes, challenging previous assumptions that compactness is directly correlated with the propensity for explosion. The complexity in the mass profile of progenitors at various stages plays a deterministic role in the eventual explosion or implosion of the stellar bodies.
• Explosion Energy and Morphology: A discernible pattern emerges from the simulations where lower-mass progenitors tend to result in lower-energy explosions that occur sooner after bounce, while higher-mass stars experience more delayed but potentially more energetic explosions. Notably, the majority of 3D explosions display a dominant dipole morphology, often characterized by a pinched, wasp-waist structure, a feature indicative of simultaneous accretion and explosion processes.
• Role of Neutrinos: The simulations affirm the centrality of neutrino interactions in driving explosions. Elements such as the rate of neutrino capture and the influence of many-body corrections to neutrino-nucleon scattering rates significantly impact the dynamical evolution of the core, suggesting that neutrinos continue to play a pivotal role in core-collapse supernova mechanics.
• Need for Extended Simulations: A critical insight from the paper is the requirement that simulations, particularly for more massive stars, need to be extended well beyond the initial seconds post-bounce to accurately forecast asymptotic behavior in terms of explosion energy and morphology. This highlights the resource-intensive nature of such studies, demanding prolonged simulation times to capture the full evolutionary dynamics.

Implications and Future Directions

The findings from this paper are set to influence both theoretical and observational realms. By highlighting the nuanced dependencies of supernova outcomes on pre-collapse stellar structures, these simulations provide a deeper understanding that can refine predictive models of stellar evolution and supernova occurrences.

Practically, these results could aid in interpreting supernovae's diverse observational signatures and lend insights into the conditions necessary for different types of stellar remnants, including neutron stars and black holes. This, in turn, might impact the calibration of astronomical models and improve the accuracy of associated nucleosynthesis predictions.

Concluding Remarks

The extensive 3D simulations presented by Burrows et al. mark a substantial contribution to CCSN studies, offering a more intricate understanding of the varied outcomes for different progenitor stars. The detailed exploration of factors like neutron star masses, explosion energies, and the morphology of remnant structures within these models drives home the complexity and interplay of forces at lanwe in supernova events. Future work could benefit from higher-resolution explorations and further refinement in collapse physics through enhanced computational techniques and updated physical models.