Radiation hydrodynamics with neutrinos - Variable Eddington factor method for core-collapse supernova simulations

By Markus Rampp, Hans-Thomas Janka. 2002

202 citations recorded by the source corpus.

Neutrino transport and neutrino interactions in dense matter play a crucial role in stellar core collapse, supernova explosions and neutron star formation. Here we present a detailed description of a new numerical code for treating the time and energy dependent neutrino transport in hydrodynamical simulations of such events. The code is based on a variable Eddington factor method to deal with the integro-differential character of the Boltzmann equation. The moments of the neutrino distribution function and the energy and lepton number exchange with the stellar medium are determined by iteratively solving the zeroth and first order moment equations in combination with a model Boltzmann equation. The latter is discretized on a grid of tangent rays. The integration of the transport equations and the neutrino source terms is performed in a time-implicit way. In the present version of the program, the transport part is coupled to an explicit hydrodynamics code which follows the evolution of the stellar plasma by a finite-volume method with piecewise parabolic interpolation, using a Riemann solver to calculate the hydrodynamic states. The neutrino source terms are implemented in an operator-split step. Neutrino transport and hydrodynamics can be calculated with different spatial grids and different time steps. The structure of the described code is modular and offers a high degree of flexibility for an application to relativistic and multi-dimensional problems at different levels of refinement and accuracy. We critically evaluate results for a number of test cases, including neutrino transport in rapidly moving stellar media and approximate relativistic core collapse, and suggest a path for generalizing the code to be used in multi-dimensional simulations of convection in neutron stars and supernovae.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/af2c763a0406724f7165795d2c3061f271bf1224

Citations in the corpus

Nuclear weak-interaction processes in stars (2002, unknown): “The crucial weak processes during the collapse are (Bruenn, 1985; Burrows, 2001; Rampp and Janka, 2002): p+ e− ⇄ n+ νe (8a) n+ e+ ⇄ p+ ν̄e (8b) (A,Z) + e− ⇄ (A,Z − 1) + νe (8c) (A,Z) + e+ ⇄ (A,Z + 1) + ν̄e (8d) ν +N ⇄ ν +N (8e) N +N ⇄ N +N + ν + ν̄ (8f) ν + (A,Z) ⇄ ν + (A,Z) (8g) ν + e± ⇄ ν + e±…”
Postbounce Evolution of Core-Collapse Supernovae: Long-Term Effects of the Equation of State (2005, unknown): “…hand, spherically symmetric supernova simulations of late have removed the uncertainty of neutrino-transport and clarified the role of neutrinos in core-collapse and shock propagation (Rampp & Janka 2000; Liebendörfer et al. 2001; Mezzacappa et al. 2001; Rampp & Janka 2002; Thompson et al. 2003).”
A New Mechanism for Core-Collapse Supernova Explosions (2005, unknown): “This phenomenon was previously seen by, among others, Herant et al. (1994), Burrows et al. (1995), Fryer & Warren (2002), Rampp & Janka (2002), Scheck et al. (2004), Janka et al. (2005a, 2005b), and Buras et al. (2006).”
Supernova Simulations with Boltzmann Neutrino Transport: A Comparison of Methods (2003, unknown): “…is handled in an operator-split step and is calculated by a variable Eddington factor closure of neutrino energy, number, and momentum equations, where the variable Eddington factor is derived from the formal solution of a spherically averaged model Boltzmann equation (Rampp & Janka 2002).”
AN OPEN-SOURCE NEUTRINO RADIATION HYDRODYNAMICS CODE FOR CORE-COLLAPSE SUPERNOVAE (2014, unknown): “One can also define moment schemes where the closure is not analytic, but rather one has 3 a variable Eddington tensor (Burrows et al. 2000; Thompson et al. 2003; Rampp & Janka 2002; Buras et al. 2006b,a).”
The Spin Periods and Rotational Profiles of Neutron Stars at Birth (2005, unknown): “However, using numerical simulations that incorporate Boltzmann neutrino transfer and the best available physics, a number of groups have shown that this mechanism does not succeed in spherical symmetry (Liebendörfer et al. 2001; Mezzacappa et al. 2001; Rampp & Janka 2002; Thompson et al. 2003).”
A MODEL FOR GRAVITATIONAL WAVE EMISSION FROM NEUTRINO-DRIVEN CORE-COLLAPSE SUPERNOVAE (2009, unknown): “However, detailed one-dimensional (1D) simulations have shown that this mechanism, the neutrino mechanism, fails in 1D (Liebendörfer et al. 2001b,a; Rampp & Janka 2002; Buras et al. 2003; Thompson et al. 2003; Liebendörfer et al. 2005), except for the least massive of the massive stars (Kitaura…”
Equation-of-state dependent features in shock-oscillation modulated neutrino and gravitational-wave signals from supernovae (2008, unknown): “The 2D simulations discussed in this paper were performed with the Prometheus-Vertex code, whose numerical aspects and the implemented microphysics were described by Rampp & Janka (2002) and Buras et al. (2006a), and the publications quoted in those papers.”
Explosion mechanism, neutrino burst and gravitational wave in core-collapse supernovae (2005, unknown): “This figure is taken from Rampp & Janka (2002)[296].”
Exploring the relativistic regime with Newtonian hydrodynamics: an improved effective gravitational potential for supernova simulations (2005, unknown): “On the other hand, we used the computationally expensive Vertex code (Rampp & Janka 2002) for spherically symmetric supernova simulations including neutrino transport and a microphysical equation of state (EoS).”
NEW TWO-DIMENSIONAL MODELS OF SUPERNOVA EXPLOSIONS BY THE NEUTRINO-HEATING MECHANISM: EVIDENCE FOR DIFFERENT INSTABILITY REGIMES IN COLLAPSING STELLAR CORES (2012, unknown): “CoCoNuT is coupled to the neutrino transport moduleVertex (Rampp & Janka 2002), which employs a variable Eddington factor technique to solve the moment equations for the neutrino energy and momentum density with a closure provided by the formal solution of a simplified Boltzmann equation.”
Toward Gravitational Wave Signals from Realistic Core-Collapse Supernova Models (2003, unknown): “…the spherical part of the gravitational potential with correction terms due to the pressure and energy of the stellar medium and the neutrinos, which are deduced from a comparison of the Newtonian and relativistic equations of motion in spherical symmetry (Keil et al. 1996; Rampp & Janka 2002).”
Two-Dimensional Multiangle, Multigroup Neutrino Radiation-Hydrodynamic Simulations of Postbounce Supernova Cores (2008, unknown): “…in the core-collapse context (Mezzacappa & Bruenn 1993a; Messer et al. 1998; Burrows et al. 2000; Yamada et al. 1999; Mezzacappa & Messer 1999; Rampp & Janka 2002; Liebendörfer et al. 2004; Hubeny & Burrows 2007), but general Boltzmann transport in multiple spatial dimensions is…”
Multidimensional supernova simulations with approximative neutrino transport. II. Convection and the (2007, unknown): “Compared to supernova simulations with a state-of-the-art energy-dependent description of the neutrino transport (in spherical symmetry see, e.g., Rampp & Janka 2002; Liebendörfer et al. 2001; Liebendörfer et al. 2005; Thompson et al. 2003, and for multigroup transport also in 2D, see, e.g., Buras…”
A NEW MULTI-DIMENSIONAL GENERAL RELATIVISTIC NEUTRINO HYDRODYNAMICS CODE OF CORE-COLLAPSE SUPERNOVAE. III. GRAVITATIONAL WAVE SIGNALS FROM SUPERNOVA EXPLOSION MODELS (2012, unknown): “Prometheus solves the equation of Newtonian hydrodynamics, but can optionally account for some effects of strong-field gravity by means of a modified gravitational potential (“effective potential”; Rampp & Janka 2002; Marek et al. 2006).”
Shock Breakout in Core-Collapse Supernovae and Its Neutrino Signature (2002, unknown): “…progenitor model has not been used in any of the recent supernova modeling done by groups employing sophisticated neutrino transport (Rampp 2000; Rampp & Janka 2000, 2002; Liebendörfer et al. 2001; Liebendörfer, Mezzacappa, & Thielemann 2001; Mezzacappa et al. 2001), we find that the basic…”
Supernova simulations from a 3D progenitor model - Impact of perturbations and evolution of explosion properties (2017, unknown): “Nuclear statistical equilibrium is assumed above 5 × 109 K, and nuclear reactions below this temperature are treated using the approximate “flashing” method of Rampp & Janka (2002).”