Non-Radial Instabilities and Progenitor Asphericities in Core-Collapse Supernovae

By Bernhard Müller, Hans-Thomas Janka. 2014

173 citations recorded by the source corpus.

Since core-collapse supernova simulations still struggle to produce robust neutrino-driven explosions in 3D, it has been proposed that asphericities caused by convection in the progenitor might facilitate shock revival by boosting the activity of non-radial hydrodynamic instabilities in the post-shock region. We investigate this scenario in depth using 42 relativistic 2D simulations with multi-group neutrino transport to examine the effects of velocity and density perturbations in the progenitor for different perturbation geometries that obey fundamental physical constraints (like the anelastic condition). As a framework for analysing our results, we introduce semi-empirical scaling laws relating neutrino heating, average turbulent velocities in the gain region, and the shock deformation in the saturation limit of non-radial instabilities. The squared turbulent Mach number, , reflects the violence of aspherical motions in the gain layer, and explosive runaway occurs for ~0.3, corresponding to a reduction of the critical neutrino luminosity by ~25% compared to 1D. In the light of this theory, progenitor asphericities aid shock revival mainly by creating anisotropic mass flux onto the shock: Differential infall efficiently converts velocity perturbations in the progenitor into density perturbations (Delta rho/rho) at the shock of the order of the initial convective Mach number Ma. The anisotropic mass flux and ram pressure deform the shock and thereby amplify post-shock turbulence. Large-scale (l=2,l=1) modes prove most conducive to shock revival, whereas small-scale perturbations require unrealistically high convective Mach numbers. Initial density perturbations in the progenitor are only of order Ma^2 and therefore play a subdominant role.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/e03da3462e1a4a3c140e32c5a804fb0d89ba489e

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Citations in the corpus

NEUTRINO-DRIVEN EXPLOSION OF A 20 SOLAR-MASS STAR IN THREE DIMENSIONS ENABLED BY STRANGE-QUARK CONTRIBUTIONS TO NEUTRINO–NUCLEON SCATTERING (2015, background): “Couch & Ott (2013), Couch et al. (2015), and Müller & Janka (2015) indeed confirmed long-standing speculations that large-amplitude perturbations of low-order modes in the convective shell-burning layers (e.g., Arnett & Meakin 2011, and references therein) might facilitate the development of…”
What can be learned from a future supernova neutrino detection (2017, background): “difference between whether or not a star explodes [57, 58, 59].”
Characterizing the Gravitational Wave Signal from Core-collapse Supernovae (2018, methodology): “In particular, we perturb the velocity in the region r200 km 1000 km using the prescription introduced by Müller & Janka (2015) with a maximum amplitude perturbation of -100 km s 1.”
The Status of Multi-Dimensional Core-Collapse Supernova Models (2016, methodology): “The more extensive 2D parameter study of different solenoidal and compressive velocity perturbations and density perturbations by Müller & Janka (2015) established that both significant perturbation velocities (Ma & 0.1) as well as large-scale angular structures (angular wavenumber ` .”
Three-dimensional simulations of neutrino-driven core-collapse supernovae from low-mass single and binary star progenitors (2018, methodology): “In this paper, we have presented a suite of 3D supernova models of low-mass hydrogen-rich and (ultra)-stripped-envelope progenitors obtained with the CoCoNuT-FMT code (Müller & Janka 2015).”
Physics of Core-Collapse Supernovae in Three Dimensions: a Sneak Preview (2016, background): “The path to generalize this condition to the multidimensional case was exemplified by Müller & Janka (2015) and Summa et al. (2015).”
Exploring Fundamentally Three-dimensional Phenomena in High-fidelity Simulations of Core-collapse Supernovae (2018, methodology): “In the notation of Müller & Janka (2015), for the silicon shell we take n = 1, ` = 9, and m = 5.”
A successful 3D core-collapse supernova explosion model (2018, methodology): “After mapping, we impose velocity perturbations (for the 2D and 3D, but not 1D, simulations) following Müller & Janka (2015) in three spatially distinct regions (50 − 85 km, 90 − 250 km, and 260 − 500 km), with a maximum speed of 500 km s−1 and harmonic quantum numbers of l = 2, m = 1, and n = 5…”
Supernova simulations from a 3D progenitor model - Impact of perturbations and evolution of explosion properties (2017, methodology): “…simplifying assumptions, but still achieves reasonable quantitative agreement with more sophisticated methods for many of the quantities relevant for the supernova explosion problem (neutrino luminosities and mean energies, heating conditions, etc.) as shown in Appendix A of Müller & Janka (2015).”
The overarching framework of core-collapse supernova explosions as revealed by 3D fornax simulations (2019, methodology): “…instabilities, very modest initial perturbations to the velocity field of amplitude 100 km s−1 and with ` = 10, m = 1, and n = 4, using the prescription of Müller & Janka (2015), were imposed 10 milliseconds (ms) after bounce to the 3D model that was mapped from the 1D model followed to collapse.”
A simple approach to the supernova progenitor–explosion connection (2016, methodology): “…the shock may still be missing (such as strong seed perturbations from convective burning in the progenitor; Couch & Ott 2013; Couch et al. 2015 ; M¨uller & Janka 2015), Finally, since our ﬁts for the shock radius, and the advection and heating time-scales are already based on 2D and 3D…”
A TWO-PARAMETER CRITERION FOR CLASSIFYING THE EXPLODABILITY OF MASSIVE STARS BY THE NEUTRINO-DRIVEN MECHANISM (2015, background): “…2015), and that asymmetries and perturbations in the shell-burning layers of the pre-collapse core might have important consequences for the development of SN explosions by the neutrino-driven mechanism (e.g., Arnett & Meakin 2011; Couch & Ott 2013, 2015; Müller & Janka 2015; Couch et al. 2015).”
Gravitational wave signals from 3D neutrino hydrodynamics simulations of core-collapse supernovae (2016, methodology): “Classical photon-based observations of supernovae and their remnants (e.g. mixing in the envelope, see Wongwathanarat, M¨uller & Janka 2015 and references therein; pulsar kicks, Scheck et al. 2006; Wongwathanarat, Janka & M¨uller 2010; Nordhaus etal.2012;Wongwathanarat,Janka&M¨uller2013)provideonlyi”
Neutron Star Kicks by the Gravitational Tug-boat Mechanism in Asymmetric Supernova Explosions: Progenitor and Explosion Dependence (2016, background): “…and density perturbations in the convective oxygen and silicon burning shells are likely to have an effect on the asymmetry of the SN explosion (e.g. Arnett & Meakin 2011; Couch & Ott 2013; Couch et al. 2015; Müller & Janka 2015; Chatzopoulos et al. 2016; Müller et al. 2016b; Müller 2016).”
The Gravitational Wave Signal from Core-collapse Supernovae (2018, background): “…instabilities and the associated turbulent pressure behind the stalled shock (Burrows et al. 1995; Murphy et al. 2013; Couch & Ott 2015; Müller & Janka 2015; Abdikamalov et al. 2016; Takahashi et al. 2016; Müller et al. 2017), which also increases the exposure of matter to neutrino…”