scholarly journals Gravitational Radiation from Standing Accretion Shock Instability in Core‐Collapse Supernovae

2007 ◽  
Vol 655 (1) ◽  
pp. 406-415 ◽  
Author(s):  
Kei Kotake ◽  
Naofumi Ohnishi ◽  
Shoichi Yamada
Keyword(s):  
Gravitational Radiation ◽  
Core Collapse ◽  
Accretion Shock

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.

scholarly journals Gravitational radiation from rotational core collapse: Effects of magnetic fields and realistic equations of state

2004 ◽  
Vol 69 (12) ◽  
Author(s):  
Kei Kotake ◽  
Shoichi Yamada ◽  
Katsuhiko Sato ◽  
Kohsuke Sumiyoshi ◽  
Hiroyuki Ono ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Gravitational Radiation ◽  
Equations Of State ◽  
Core Collapse

Spiral mode of standing accretion shock instability in core-collapse supernovae

2008 ◽  
pp. 43-47
Author(s):  
Wakana Iwakami ◽  
Naofumi Ohnishi ◽  
Kei Kotake ◽  
Shoichi Yamada ◽  
Keisuke Sawada
Keyword(s):  
Core Collapse ◽  
Accretion Shock

scholarly journals Acoustic wave generation in collapsing massive stars with convective shells

2020 ◽  
Vol 493 (3) ◽  
pp. 3496-3512 ◽  
Author(s):  
Ernazar Abdikamalov ◽  
Thierry Foglizzo
Keyword(s):  
Acoustic Waves ◽  
Massive Stars ◽  
Core Collapse ◽  
Core Collapse Supernova ◽  
Stellar Collapse ◽  
Acoustic Wave Generation ◽  
Supernova Explosions ◽  
Accretion Shock ◽  
Stationary Background ◽  
Hydrodynamics Equations

ABSTRACT The convection that takes place in the innermost shells of massive stars plays an important role in the formation of core-collapse supernova explosions. Upon encountering the supernova shock, additional turbulence is generated, amplifying the explosion. In this work, we study how the convective perturbations evolve during the stellar collapse. Our main aim is to establish their physical properties right before they reach the supernova shock. To this end, we solve the linearized hydrodynamics equations perturbed on a stationary background flow. The latter is approximated by the spherical transonic Bondi accretion, while the convective perturbations are modelled as a combination of entropy and vorticity waves. We follow their evolution from large radii, where convective shells are initially located, down to small radii, where they are expected to encounter the accretion shock above the proto-neutron star. Considering typical vorticity perturbations with a Mach number ∼0.1 and entropy perturbations with magnitude ∼0.05kb/baryon, we find that the advection of these perturbations down to the shock generates acoustic waves with a relative amplitude $\delta {\rm p}/\gamma {\rm p} \lesssim 10{{\ \rm per\ cent}}$, in agreement with published numerical simulations. The velocity perturbations consist of contributions from acoustic and vorticity waves with values reaching ${\sim}10{{\ \rm per\ cent}}$ of the sound speed ahead of the shock. The perturbation amplitudes decrease with increasing ℓ and initial radii of the convective shells.

scholarly journals Standing accretion shock instability: numerical simulations of core-collapse supernova

2008 ◽  
Vol 112 (4) ◽  
pp. 042018 ◽  
Author(s):  
N Ohnishi ◽  
W Iwakami ◽  
K Kotake ◽  
S Yamada ◽  
S Fujioka ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Core Collapse ◽  
Core Collapse Supernova ◽  
Accretion Shock

GRAVITATIONAL COLLAPSE OF MASSIVE STARS AS A PROBE INTO HOT DENSE MATTER

2008 ◽  
Vol 23 (27n30) ◽  
pp. 2443-2450 ◽  
Author(s):  
SHOICHI YAMADA
Keyword(s):  
Equation Of State ◽  
Gravitational Collapse ◽  
Nuclear Physics ◽  
Massive Stars ◽  
Dense Matter ◽  
High Energy ◽  
Compact Objects ◽  
Core Collapse ◽  
Accretion Shock ◽  
Very High

Nuclear physics is an indispensable input for the investigation of high energy astrophysical phenomena involving compact objects. In this paper I take a gravitational collapse of massive stars as an example and show how the macroscopic dynamics is influenced by the properties of nuclei and nuclear matter. I will discuss two topics that are rather independent of each other. The first one is the interplay of neutrino-nuclei inelastic scatterings and the standing accretion shock instability in the core of core collapse supernovae and the second is concerning the neutrino emissions from black hole formations and their dependence on the equation of state at very high densities. In the latter, I will also demonstrate that future astronomical observations might provide us with valuable information on the equation of state of hot dense matter.

scholarly journals Inelastic Neutrino‐Helium Scatterings and Standing Accretion Shock Instability in Core‐Collapse Supernovae

2007 ◽  
Vol 667 (1) ◽  
pp. 375-381 ◽  
Author(s):  
Naofumi Ohnishi ◽  
Kei Kotake ◽  
Shoichi Yamada
Keyword(s):  
Core Collapse ◽  
Accretion Shock
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