scholarly journals The mechanism(s) of core-collapse supernovae

2017 ◽  
Vol 375 (2105) ◽  
pp. 20160271 ◽  
Author(s):  
Sean M. Couch
Keyword(s):  
Massive Stars ◽  
Three Dimensional ◽  
Short Review ◽  
Core Collapse ◽  
The Impact ◽  
Three Dimensional Simulations

Core-collapse supernovae (CCSNe) are the explosions that attend the deaths of massive stars. Despite decades of research, several aspects of the mechanism that drives these explosions remain uncertain and the subjects of continued investigation. In this short review, I will give an overview of the CCSN mechanism and current research in the field. In particular, I will focus on recent results from three-dimensional simulations and the impact of turbulence and detailed non-spherical progenitor structure on CCSNe. This contribution is based on a talk given at the ‘Bridging the Gap’ workshop at Chicheley Hall on 2 June 2016. This article is part of the themed issue ‘Bridging the gap: from massive stars to supernovae’.

scholarly journals The impact of fallback on the compact remnants and chemical yields of core-collapse supernovae

2020 ◽  
Vol 495 (4) ◽  
pp. 3751-3762 ◽  
Author(s):  
Conrad Chan ◽  
Bernhard Müller ◽  
Alexander Heger
Keyword(s):  
Binding Energy ◽  
Gamma Ray ◽  
Three Dimensional ◽  
Explosion Energy ◽  
Core Collapse ◽  
Abundance Patterns ◽  
Small Set ◽  
The Impact ◽  
Disc Formation ◽  
Three Dimensional Simulations

ABSTRACT Fallback in core-collapse supernovae plays a crucial role in determining the properties of the compact remnants and of the ejecta composition. We perform three-dimensional simulations of mixing and fallback for selected non-rotating supernova models to study how explosion energy and asymmetries correlate with the remnant mass, remnant kick, and remnant spin. We find that the strongest kick and spin are imparted by partial fallback in an asymmetric explosion. Black hole (BH) kicks of several hundred $\mathrm{km}\, \mathrm{s}^{-1}$ and spin parameters of $\mathord {\sim }0.25$ can be obtained in this scenario. If the initial explosion energy barely exceeds the envelope binding energy, stronger fallback results, and the remnant kick and spin remain small. If the explosion energy is high with respect to the envelope binding energy, there is little fallback with a small effect on the remnant kick, but the spin-up by fallback can be substantial. For a non-rotating $12\, \mathrm{M}_\odot$ progenitor, we find that the neutron star is spun up to millisecond periods. The high specific angular momentum of the fallback material can also lead to disc formation around BHs. Fallback may thus be a pathway towards millisecond-magnetar or collapsar-type engines for hypernovae and gamma-ray bursts that does not require rapid progenitor rotation. Within our small set of simulations, none reproduced the peculiar layered fallback necessary to explain the metal-rich iron-poor composition of many carbon-enhanced metal-poor (CEMP) stars. Models with different explosion energy and different realizations of asymmetries may, however, be compatible with CEMP abundance patterns.

scholarly journals One-, Two-, and Three-dimensional Simulations of Oxygen-shell Burning Just before the Core Collapse of Massive Stars

2019 ◽  
Vol 881 (1) ◽  
pp. 16 ◽  
Author(s):  
Takashi Yoshida ◽  
Tomoya Takiwaki ◽  
Kei Kotake ◽  
Koh Takahashi ◽  
Ko Nakamura ◽  
...  
Keyword(s):  
Massive Stars ◽  
Three Dimensional ◽  
Core Collapse ◽  
The Core ◽  
Three Dimensional Simulations

Vortex rings impinging on walls: axisymmetric and three-dimensional simulations

1993 ◽  
Vol 256 ◽  
pp. 615-646 ◽  
Author(s):  
Paolo Orlandi ◽  
Roberto Verzicco
Keyword(s):  
Numerical Simulations ◽  
Strain Tensor ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Vortex Rings ◽  
Compression Phase ◽  
Vortex Pairing ◽  
The Impact ◽  
Good Agreement ◽  
Three Dimensional Simulations

Accurate numerical simulations of vortex rings impinging on flat boundaries revealed the same features observed in experiments. The results for the impact with a free-slip wall compared very well with previous numerical simulations that used spectral methods, and were also in qualitative agreement with experiments. The present simulation is mainly devoted to studying the more realistic case of rings interacting with a no-slip wall, experimentally studied by Walker et al. (1987). All the Reynolds numbers studied showed a very good agreement between experiments and simulations, and, at Rev > 1000 the ejection of a new ring from the wall was seen. Axisymmetric simulations demonstrated that vortex pairing is the physical mechanism producing the ejection of the new ring. Three-dimensional simulations were also performed to investigate the effects of azimuthal instabilities. These simulations have confirmed that high-wavenumber instabilities originate in the compression phase of the secondary ring within the primary one. The large instability of the secondary ring has been explained by analysis of the rate-of-strain tensor and vorticity alignment. The differences between passive scalars and the vorticity field have been also investigated.

scholarly journals A systematic study of proto-neutron star convection in three-dimensional core-collapse supernova simulations

2020 ◽  
Vol 492 (4) ◽  
pp. 5764-5779 ◽  
Author(s):  
Hiroki Nagakura ◽  
Adam Burrows ◽  
David Radice ◽  
David Vartanyan
Keyword(s):  
Neutron Star ◽  
Systematic Study ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Core Collapse ◽  
Core Collapse Supernova ◽  
Tau Neutrinos ◽  
The Impact ◽  
Proto Neutron Star

ABSTRACT This paper presents the first systematic study of proto-neutron star (PNS) convection in three dimensions (3D) based on our latest numerical fornax models of core-collapse supernova (CCSN). We confirm that PNS convection commonly occurs, and then quantify the basic physical characteristics of the convection. By virtue of the large number of long-term models, the diversity of PNS convective behaviour emerges. We find that the vigour of PNS convection is not correlated with CCSN dynamics at large radii, but rather with the mass of PNS − heavier masses are associated with stronger PNS convection. We find that PNS convection boosts the luminosities of νμ, ντ, $\bar{\nu }_{\mu }$, and $\bar{\nu }_{\tau }$ neutrinos, while the impact on other species is complex due to a competition of factors. Finally, we assess the consequent impact on CCSN dynamics and the potential for PNS convection to generate pulsar magnetic fields.

scholarly journals Three-dimensional Simulations of Massive Stars. I. Wave Generation and Propagation

2019 ◽  
Vol 876 (1) ◽  
pp. 4 ◽  
Author(s):  
P. V. F. Edelmann ◽  
R. P. Ratnasingam ◽  
M. G. Pedersen ◽  
D. M. Bowman ◽  
V. Prat ◽  
...  
Keyword(s):  
Massive Stars ◽  
Three Dimensional ◽  
Wave Generation ◽  
Three Dimensional Simulations

scholarly journals The Status of Multi-Dimensional Core-Collapse Supernova Models

2016 ◽  
Vol 33 ◽  
Author(s):  
B. Müller
Keyword(s):  
Initial Conditions ◽  
Massive Stars ◽  
Core Collapse ◽  
Solar Mass ◽  
Convective Boundary ◽  
3D Simulations ◽  
Core Collapse Supernova ◽  
Wide Range ◽  
Supernova Explosions ◽  
The Impact

AbstractModels of neutrino-driven core-collapse supernova explosions have matured considerably in recent years. Explosions of low-mass progenitors can routinely be simulated in 1D, 2D, and 3D. Nucleosynthesis calculations indicate that these supernovae could be contributors of some lighter neutron-rich elements beyond iron. The explosion mechanism of more massive stars remains under investigation, although first 3D models of neutrino-driven explosions employing multi-group neutrino transport have become available. Together with earlier 2D models and more simplified 3D simulations, these have elucidated the interplay between neutrino heating and hydrodynamic instabilities in the post-shock region that is essential for shock revival. However, some physical ingredients may still need to be added/improved before simulations can robustly explain supernova explosions over a wide range of progenitors. Solutions recently suggested in the literature include uncertainties in the neutrino rates, rotation, and seed perturbations from convective shell burning. We review the implications of 3D simulations of shell burning in supernova progenitors for the ‘perturbations-aided neutrino-driven mechanism,’ whose efficacy is illustrated by the first successful multi-group neutrino hydrodynamics simulation of an 18 solar mass progenitor with 3D initial conditions. We conclude with speculations about the impact of 3D effects on the structure of massive stars through convective boundary mixing.

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