Large eddy simulations of magnetized mergers of neutron stars with neutrinos

Palenzuela, Carlos; Liebling, Steven L.; Miñano, Borja

doi:10.1103/physrevd.105.103020

Cited by 19 publications

(14 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A conceptually similar algorithm that does not rely on the existence of an underlying cartesian grid has also been developed in Perego et al (2014a), allowing for the easy use of this method in grid-less simulations (e.g. SPH), while an improved numerical methods to solve for s m by solving the eikonal equation has been proposed by Palenzuela et al (2022).…”

Section: Leakage In General Relativistic Merger Simulationsmentioning

confidence: 99%

Neutrino transport in general relativistic neutron star merger simulations

Foucart

2023

Living Rev Comput Astrophys

View full text Add to dashboard Cite

Numerical simulations of neutron star–neutron star and neutron star–black hole binaries play an important role in our ability to model gravitational-wave and electromagnetic signals powered by these systems. These simulations have to take into account a wide range of physical processes including general relativity, magnetohydrodynamics, and neutrino radiation transport. The latter is particularly important in order to understand the properties of the matter ejected by many mergers, the optical/infrared signals powered by nuclear reactions in the ejecta, and the contribution of that ejecta to astrophysical nucleosynthesis. However, accurate evolutions of the neutrino transport equations that include all relevant physical processes remain beyond our current reach. In this review, I will discuss the current state of neutrino modeling in general relativistic simulations of neutron star mergers and of their post-merger remnants. I will focus on the three main types of algorithms used in simulations so far: leakage, moments, and Monte-Carlo scheme. I will review the advantages and limitations of each scheme, as well as the various neutrino–matter interactions that should be included in simulations. We will see that the quality of the treatment of neutrinos in merger simulations has greatly increased over the last decade, but also that many potentially important interactions remain difficult to take into account in simulations (pair annihilation, oscillations, inelastic scattering).

show abstract

Section: Leakage In General Relativistic Merger Simulationsmentioning

confidence: 99%

Neutrino transport in general relativistic neutron star merger simulations

Foucart

2023

Living Rev Comput Astrophys

View full text Add to dashboard Cite

show abstract

“…We refer to this outcome as a short-lived remnant (Baumgarte et al 2000;Rosswog & Davies 2002;Shibata & Taniguchi 2006;Baiotti et al 2008;Sekiguchi et al 2011;Palenzuela et al 2015;Kiuchi et al 2023). If this does not happen, i.e., for long-lived remnants, then the dynamics transitions to being dominated by neutrino losses and turbulence (Hotokezaka et al 2013;Radice 2017;Kiuchi et al 2018;Radice et al 2018a;Palenzuela et al 2022aPalenzuela et al , 2022b.…”

Section: Introductionmentioning

confidence: 99%

“…Few numerical relativity simulations exist of the formation of long-lived remnants, some even spanning many tens of milliseconds (Giacomazzo & Perna 2013;Kastaun et al 2016;Fujibayashi et al 2018;Radice et al 2018a;De Pietri et al 2020;Ciolfi & Kalinani 2020;Nedora et al 2021). However, current simulations either span a short timescale after the merger (Foucart et al 2020;Vincent et al 2020;Zappa et al 2023) or adopt schemes, such as the leakage scheme, which do not capture the correct thermodynamic equilibrium of matter and neutrinos (e.g., Sekiguchi et al 2015;Perego et al 2019;Hammond et al 2021;Palenzuela et al 2022b).…”

Section: Introductionmentioning

confidence: 99%

Ab-initio General-relativistic Neutrino-radiation Hydrodynamics Simulations of Long-lived Neutron Star Merger Remnants to Neutrino Cooling Timescales

Radice,

Bernuzzi

2023

ApJ

View full text Add to dashboard Cite

We perform the first 3D ab-initio general-relativistic neutrino-radiation hydrodynamics of a long-lived neutron star merger remnant spanning a fraction of its cooling timescale. We find that neutrino cooling becomes the dominant energy loss mechanism after the gravitational-wave dominated phase (∼20 ms postmerger). Electron flavor antineutrino luminosity dominates over electron flavor neutrino luminosity at early times, resulting in a secular increase of the electron fraction in the outer layers of the remnant. However, the two luminosities become comparable ∼20–40 ms postmerger. A dense gas of electron antineutrinos is formed in the outer core of the remnant at densities ∼1014.5 g cm−3, corresponding to temperature hot spots. The neutrinos account for ∼10% of the lepton number in this region. Despite the negative radial temperature gradient, the radial entropy gradient remains positive, and the remnant is stably stratified according to the Ledoux criterion for convection. A massive accretion disk is formed from the material squeezed out of the collisional interface between the stars. The disk carries a large fraction of the angular momentum of the system, allowing the remnant massive neutron star to settle to a quasi-steady equilibrium within the region of possible, stable, rigidly rotating configurations. The remnant is differentially rotating, but it is stable against the magnetorotational instability. Other MHD mechanisms operating on longer timescales are likely responsible for the removal of the differential rotation. Our results indicate the remnant massive neutron star is thus qualitatively different from a protoneutron stars formed in core-collapse supernovae.

show abstract

“…The simplest and most inexpensive approach is the neutrino leakage scheme (see, e.g., Sekiguchi 2010; Deaton et al 2013;Werneck et al 2022;Palenzuela et al 2022b). This approximation seeks to account for changes in the electron fraction and in the energy losses due to the emission of neutrinos.…”

Section: Introductionmentioning

confidence: 99%

“…The leakage scheme replaces the transport equations with an estimation of the cooling rate based on the optical depth, which requires a minimization of the path integral of the opacity in all possible directions. Although this is an expensive global calculation, the shortest distance between a point and a surface-level can also be calculated efficiently by solving instead the eikonal equation (Neilsen et al 2014;Palenzuela et al 2022b). Although many groups (see refs.…”

Section: Introductionmentioning

confidence: 99%

Global high-order numerical schemes for the time evolution of the general relativistic radiation magneto-hydrodynamics equations

Izquierdo¹,

Pareschi²,

Miñano³

et al. 2022

Preprint

View full text Add to dashboard Cite

Modeling correctly the transport of neutrinos is crucial in some astrophysical scenarios such as core-collapse supernovae and binary neutron star mergers. In this paper, we focus on the truncatedmoment formalism, considering only the first two moments (M1 scheme) within the grey approximation, which reduces Boltzmann seven-dimensional equation to a system of 3 + 1 equations closely resembling the hydrodynamic ones. Solving the M1 scheme is still mathematically challenging, since it is necessary to model the radiation-matter interaction in regimes where the evolution equations become stiff and behave as an advection-diffusion problem. Here, we present different global, highorder time integration schemes based on Implicit-Explicit Runge-Kutta (IMEX) methods designed to overcome the time-step restriction caused by such behavior while allowing us to use the explicit RK commonly employed for the MHD and Einstein equations. Finally, we analyze their performance in several numerical tests.

show abstract

Large eddy simulations of magnetized mergers of neutron stars with neutrinos

Cited by 19 publications

References 65 publications

Neutrino transport in general relativistic neutron star merger simulations

Neutrino transport in general relativistic neutron star merger simulations

Ab-initio General-relativistic Neutrino-radiation Hydrodynamics Simulations of Long-lived Neutron Star Merger Remnants to Neutrino Cooling Timescales

Global high-order numerical schemes for the time evolution of the general relativistic radiation magneto-hydrodynamics equations

Contact Info

Product

Resources

About