scholarly journals Cutting-edge issues in core-collapse supernova theory

2011 ◽  
Vol 7 (S279) ◽  
pp. 126-133
Author(s):  
Kei Kotake
Keyword(s):  
General Relativity ◽  
First Generation ◽  
Three Dimensional ◽  
Cutting Edge ◽  
Core Collapse ◽  
Hydrodynamic Simulations ◽  
3D Simulations ◽  
Core Collapse Supernova ◽  
Neutrino Radiation ◽  
Explosion Mechanism

AbstractBased on our multi-dimensional neutrino-radiation hydrodynamic simulations, we report several cutting-edge issues about the long-veiled explosion mechanism of core-collapse supernovae (CCSNe). In this contribution, we pay particular attention to whether three-dimensional (3D) hydrodynamics and/or general relativity (GR) would or would not help the onset of explosions. Our results from the first generation of full GR 3D simulations including approximate neutrino transport are quite optimistic, indicating that both of the two ingredients can foster neutrino-driven explosions. We give an outlook with a summary of the most urgent tasks to draw a robust conclusion to our findings.

Recent Status of Multi-Dimensional Core-Collapse Supernova Models

2015 ◽  
Vol 11 (A29A) ◽  
pp. 340-344
Author(s):  
Kei Kotake ◽  
Ko Nakamura ◽  
Tomoya Takiwaki
Keyword(s):  
Energy Transport ◽  
Unique Feature ◽  
Three Dimensional ◽  
Radiation Hydrodynamics ◽  
Core Collapse ◽  
Core Collapse Supernova ◽  
Self Consistent ◽  
New Type ◽  
Explosion Mechanism ◽  
Proto Neutron Star

AbstractWe report a recent status of multi-dimensional neutrino-radiation hydrodynamics simulations for clarifying the explosion mechanism of core-collapse supernovae (CCSNe). In this contribution, we present two results, one from two-dimensional (2D) simulations using multiple progenitor models and another from three-dimensional (3D) rotational core-collapse simulation using a single progenitor. From the first ever systematic 2D simulations, it is shown that the compactness parameter ξ that characterizes the structure of the progenitors is a key to diagnose the explodability of neutrino-driven explosions. In the 3D rotating model, we find a new type of rotation-assisted explosion, which makes the explosion energy bigger than that in the non-rotating model. The unique feature has not been captured in previous 2D self-consistent rotational models because the growth of non-axisymmetric instabilities is the key to foster the explosion by enhancing the energy transport from the proto-neutron star to the gain region.

scholarly journals Spatial distribution of radionuclides in 3D models of SN 1987A and Cas A

2017 ◽  
Vol 12 (S331) ◽  
pp. 148-156 ◽  
Author(s):  
Hans-Thomas Janka ◽  
Michael Gabler ◽  
Annop Wongwathanarat
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
3D Models ◽  
Core Collapse ◽  
Mixing Processes ◽  
Free Expansion ◽  
3D Simulations ◽  
Sn 1987A ◽  
Explosion Mechanism ◽  
Cas A

AbstractFostered by the possibilities of multi-dimensional computational modeling, in particular the advent of three-dimensional (3D) simulations, our understanding of the neutrino-driven explosion mechanism of core-collapse supernovae (SNe) has experienced remarkable progress over the past decade. First self-consistent, first-principle models have shown successful explosions in 3D, and even failed cases may be cured by moderate changes of the microphysics inside the neutron star (NS), better grid resolution, or more detailed progenitor conditions at the onset of core collapse, in particular large-scale perturbations in the convective Si and O burning shells. 3D simulations have also achieved to follow neutrino-driven explosions continuously from the initiation of the blast wave, through the shock breakout from the progenitor surface, into the radioactively powered evolution of the SN, and towards the free expansion phase of the emerging remnant. Here we present results from such simulations, which form the basis for direct comparisons with observations of SNe and SN remnants in order to derive constraints on the still disputed explosion mechanism. It is shown that predictions based on hydrodynamic instabilities and mixing processes associated with neutrino-driven explosions yield good agreement with measured NS kicks, light-curve properties of SN 1987A and asymmetries of iron and 44Ti distributions observed in SN 1987A and Cassiopeia A.

scholarly journals Three-dimensional Core-collapse Supernova Simulations with 160 Isotopic Species Evolved to Shock Breakout

2021 ◽  
Vol 921 (2) ◽  
pp. 113
Author(s):  
Michael A. Sandoval ◽  
W. Raphael Hix ◽  
O. E. Bronson Messer ◽  
Eric J. Lentz ◽  
J. Austin Harris
Keyword(s):  
Three Dimensional ◽  
Core Collapse ◽  
Core Collapse Supernova ◽  
Isotopic Species

scholarly journals Stripped-envelope core-collapse supernova 56Ni masses

2020 ◽  
Vol 641 ◽  
pp. A177 ◽  
Author(s):  
N. Meza ◽  
J. P. Anderson
Keyword(s):  
Systematic Errors ◽  
Power Source ◽  
Radioactive Material ◽  
Estimation Methods ◽  
Core Collapse ◽  
Core Collapse Supernova ◽  
Explosion Mechanism ◽  
The Difference ◽  
Uniform Manner ◽  
Lower Limits

Context. The mass of synthesised radioactive material is an important power source for all supernova (SN) types. In addition, the difference of 56Ni yields statistics are relevant to constrain progenitor paths and explosion mechanisms. Aims. Here, we re-estimate the nucleosynthetic yields of 56Ni for a well-observed and well-defined sample of stripped-envelope SNe (SE-SNe) in a uniform manner. This allows us to investigate whether the observed hydrogen-rich–stripped-envelope (SN II–SE SN) 56Ni separation is due to real differences between these SN types or because of systematic errors in the estimation methods. Methods. We compiled a sample of well-observed SE-SNe and measured 56Ni masses through three different methods proposed in the literature: first, the classic “Arnett rule”; second the more recent prescription of Khatami & Kasen (2019, ApJ, 878, 56) and third using the tail luminostiy to provide lower limit 56Ni masses. These SE-SN distributions were then compared to those compiled in this article. Results. Arnett’s rule, as previously shown, gives 56Ni masses for SE-SNe that are considerably higher than SNe II. While for the distributions calculated using both the Khatami & Kasen (2019, ApJ, 878, 56) prescription and Tail 56Ni masses are offset to lower values than “Arnett values”, their 56Ni distributions are still statistically higher than that of SNe II. Our results are strongly driven by a lack of SE-SN with low 56Ni masses, that are, in addition, strictly lower limits. The lowest SE-SN 56Ni mass in our sample is of 0.015 M⊙, below which are more than 25% of SNe II. Conclusions. We conclude that there exist real, intrinsic differences in the mass of synthesised radioactive material between SNe II and SE-SNe (types IIb, Ib, and Ic). Any proposed current or future CC SN progenitor scenario and explosion mechanism must be able to explain why and how such differences arise or outline a bias in current SN samples yet to be fully explored.

scholarly journals Towards an understanding of the resolution dependence of Core-Collapse Supernova simulations

2019 ◽  
Vol 490 (4) ◽  
pp. 4622-4637 ◽  
Author(s):  
Hiroki Nagakura ◽  
Adam Burrows ◽  
David Radice ◽  
David Vartanyan
Keyword(s):  
Spatial Resolution ◽  
State Of The Art ◽  
Three Dimensional ◽  
Core Collapse ◽  
Turbulent Stress ◽  
Critical Aspect ◽  
Core Collapse Supernova ◽  
Nuclear Equation Of State ◽  
Turbulent Eddies ◽  
Polar Grid

ABSTRACT Using our new state-of-the-art core-collapse supernova (CCSN) code Fornax, we explore the dependence upon spatial resolution of the outcome and character of three-dimensional (3D) supernova simulations. For the same 19 M⊙ progenitor star, energy and radial binning, neutrino microphysics, and nuclear equation of state, changing only the number of angular bins in the θ and ϕ directions, we witness that our lowest resolution 3D simulation does not explode. However, when jumping progressively up in resolution by factors of two in each angular direction on our spherical-polar grid, models then explode, and explode slightly more vigorously with increasing resolution. This suggests that there can be a qualitative dependence of the outcome of 3D CCSN simulations upon spatial resolution. The critical aspect of higher spatial resolution is the adequate capturing of the physics of neutrino-driven turbulence, in particular its Reynolds stress. The greater numerical viscosity of lower resolution simulations results in greater drag on the turbulent eddies that embody turbulent stress, and, hence, in a diminution of their vigor. Turbulent stress not only pushes the temporarily stalled shock further out, but bootstraps a concomitant increase in the deposited neutrino power. Both effects together lie at the core of the resolution dependence we observe.

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 Effects of Small-Scale Fluctuations of Neutrino Flux in Supernova Explosions

2005 ◽  
Vol 192 ◽  
pp. 309-314
Author(s):  
Hideki Madokoro ◽  
Tetsuya Shimizu ◽  
Yuko Motizuki
Keyword(s):  
Neutrino Flux ◽  
Explosion Energy ◽  
Small Scale ◽  
Core Collapse ◽  
Effective Mechanism ◽  
Core Collapse Supernova ◽  
Neutrino Radiation ◽  
Spherical Explosion ◽  
Supernova Explosions ◽  
Neutrino Luminosity

SummaryWe examine effects of small-scale fluctuations with angle in the neutrino radiation in core-collapse supernova explosions. As the mode number of fluctuations increases, the results approach those of spherical explosion. We conclude that global anisotropy of the neutrino radiation is the most effective mechanism of increasing the explosion energy when the total neutrino luminosity is given.

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