scholarly journals Wave heating from proto-neutron star convection and the core-collapse supernova explosion mechanism

2019 ◽  
Vol 491 (4) ◽  
pp. 5376-5391 ◽  
Author(s):  
Sarah E Gossan ◽  
Jim Fuller ◽  
Luke F Roberts
Keyword(s):  
Acoustic Waves ◽  
Supernova Explosion ◽  
Core Collapse ◽  
Core Collapse Supernova ◽  
The Core ◽  
Shock Region ◽  
Wave Heating ◽  
Post Shock ◽  
Explosion Mechanism ◽  
Proto Neutron Star

ABSTRACT Our understanding of the core-collapse supernova explosion mechanism is incomplete. While the favoured scenario is delayed revival of the stalled shock by neutrino heating, it is difficult to reliably compute explosion outcomes and energies, which depend sensitively on the complex radiation hydrodynamics of the post-shock region. The dynamics of the (non-)explosion depend sensitively on how energy is transported from inside and near the proto-neutron star (PNS) to material just behind the supernova shock. Although most of the PNS energy is lost in the form of neutrinos, hydrodynamic and hydromagnetic waves can also carry energy from the PNS to the shock. We show that gravity waves excited by core PNS convection can couple with outgoing acoustic waves that present an appreciable source of energy and pressure in the post-shock region. Using one-dimensional simulations, we estimate the gravity wave energy flux excited by PNS convection and the fraction of this energy transmitted upwards to the post-shock region as acoustic waves. We find wave energy fluxes near $10^{51}\, \mathrm{erg}\, \mathrm{s}^{-1}\,$ are likely to persist for $\sim \! 1\, \mathrm{s}$ post-bounce. The wave pressure on the shock may exceed $10{{\ \rm per\ cent}}$ of the thermal pressure, potentially contributing to shock revival and, subsequently, a successful and energetic explosion. We also discuss how future simulations can better capture the effects of waves, and more accurately quantify wave heating rates.

scholarly journals On the importance of the equation of state for the neutrino-driven supernova explosion mechanism

2011 ◽  
Vol 7 (S279) ◽  
pp. 397-398 ◽  
Author(s):  
Yudai Suwa
Keyword(s):  
Equation Of State ◽  
Supernova Explosion ◽  
Shock Propagation ◽  
Core Collapse ◽  
Two Dimensional ◽  
Core Collapse Supernova ◽  
The Core ◽  
Dense Nuclear Matter ◽  
Explosion Mechanism ◽  
The Difference

AbstractWe present two-dimensional numerical simulations of core-collapse supernova including multi-energy neutrino radiative transfer. We aim to examine the influence of the equation of state (EOS) for the dense nuclear matter. We employ four sets of EOSs, namely, those by Lattimer and Swesty (LS) and Shen et al., which became standard EOSs in the core-collapse supernova community. We reconfirm that not every EOS produces an explosion in spherical symmetry, which is consistent with previous works. In two-dimensional simulations, we find that the structure of the accretion flow is significantly different between LS EOS and Shen EOS, inducing an even qualitatively different evolution of the shock wave, namely, the LS EOS leads to shock propagation beyond 2000 km from the center, while the Shen EOS shows only oscillations within 500 km. The possible origins of the difference are discussed.

scholarly journals The Core-Collapse Supernova Explosion Mechanism

2016 ◽  
Vol 12 (S329) ◽  
pp. 17-24 ◽  
Author(s):  
Bernhard Müller
Keyword(s):  
Supernova Explosion ◽  
Core Collapse ◽  
Core Collapse Supernova ◽  
The Core ◽  
Supernova Explosions ◽  
Explosion Mechanism ◽  
Standing Problem

AbstractThe explosion mechanism of core-collapse supernovae is a long-standing problem in stellar astrophysics. We briefly outline the main contenders for a solution and review recent efforts to model core-collapse supernova explosions by means of multi-dimensional simulations. Focusing on the neutrino-driven mechanism, we summarize currents efforts to predict supernova explosion and remnant properties.

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 Supplying angular momentum to the jittering jets explosion mechanism using inner convection layers

2021 ◽  
Author(s):  
Dmitry Shishkin ◽  
Noam Soker
Keyword(s):  
Angular Momentum ◽  
Three Dimensional ◽  
Mass Range ◽  
Iron Core ◽  
Core Collapse ◽  
Shock Region ◽  
Post Shock ◽  
Explosion Mechanism ◽  
Mixing Length Theory ◽  
Accretion Shock

Abstract We conduct one-dimensional stellar evolution simulations in the mass range 13 − 20M⊙ to late core collapse times and find that an inner vigorous convective zone with large specific angular momentum fluctuations appears at the edge of the iron core during the collapse. The compression of this zone during the collapse increases the luminosity there and the convective velocities, such that the specific angular momentum fluctuations are of the order of $j_{\rm conv} \simeq 5 \times 10^{15} {~\rm cm}^2 {~\rm s}^{-1}$. If we consider that three-dimensional simulations show convective velocities that are three to four times larger than what the mixing length theory gives, and that the spiral standing accretion shock instability in the post-shock region of the stalled shock at a radius of $\simeq 100 {~\rm km}$ amplify perturbations, we conclude that the fluctuations that develop during core collapse are likely to lead to stochastic (intermittent) accretion disks around the newly born neutron star. In reaching this conclusion we also make two basic assumptions with uncertainties that we discuss. Such intermittent disks can launch jets that explode the star in the frame of the jittering jets explosion mechanism.

scholarly journals Self Similar Adiabatic Strong Explosion in a Medium Gravitationally Free Falling to a Point Mass

2021 ◽  
Author(s):  
Almog Yalinewich
Keyword(s):  
Threshold Energy ◽  
Supernova Explosion ◽  
Critical Energy ◽  
Point Mass ◽  
Core Collapse ◽  
Core Collapse Supernova ◽  
Self Similar ◽  
Strong Explosion ◽  
Free Falling ◽  
Proto Neutron Star

Abstract We develop a generalisation to the classical Sedov Taylor explosion where the medium free falls to a point mass at the centre of the explosion. To verify our analytic results, we compare them to a suite of numerical simulations. We find that there exists a critical energy below which, instead of propagating outward the shock stalls and collapses under gravity. Furthermore, we find that the value of the critical energy threshold decreases when the adiabatic index increases and material is more evenly distributed within the shocked region. We apply this model to the problem of a shock bounce in core collapse supernova, in which the proto neutron star serves as the point mass. The relation between the threshold energy and the distribution of mass in the shock might help explain how turbulence prevents shock stalling and recession in a core collapse supernova explosion.

scholarly journals A shallow water analogue of asymmetric core-collapse, and neutron star kick/spin

2011 ◽  
Vol 7 (S279) ◽  
pp. 134-137
Author(s):  
Thierry Foglizzo ◽  
Frédéric Masset ◽  
Jérôme Guilet ◽  
Gilles Durand
Keyword(s):  
Neutron Star ◽  
Shallow Water ◽  
Acoustic Waves ◽  
Large Scale ◽  
Massive Stars ◽  
Core Collapse ◽  
Hydraulic Jumps ◽  
Core Collapse Supernova ◽  
Accretion Shock

AbstractMassive stars end their life with the gravitational collapse of their core and the formation of a neutron star. Their explosion as a supernova depends on the revival of a spherical accretion shock, located in the inner 200km and stalled during a few hundred milliseconds. Numerical simulations suggest that the large scale asymmetry of the neutrino-driven explosion is induced by a hydrodynamical instability named SASI. Its non radial character is able to influence the kick and the spin of the resulting neutron star. The SWASI experiment is a simple shallow water analog of SASI, where the role of acoustic waves and shocks is played by surface waves and hydraulic jumps. Distances in the experiment are scaled down by a factor one million, and time is slower by a factor one hundred. This experiment is designed to illustrate the asymmetric nature of core-collapse supernova.

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