We present results from three-dimensional, magnetohydrodynamic, core-collapse simulations of sixteen progenitors following until 0.5 s after bounce. We use non-rotating solar-metallicity progenitor models with zero-age main-sequence mass between 9 and 24 $M_{\odot}$. The examined progenitors cover a wide range of the compactness parameter including a peak around $23 M_{\odot}$. We find that neutrino-driven explosions occur for all models within 0.3 s after bounce. We also find that the properties of the explosions and the central remnants are well correlated with the compactness. Early shock evolution is sensitive to the mass accretion rate onto the central core, reflecting the density profile of the progenitor stars. The most powerful explosions with diagnostic explosion energy $E_{\rm exp} \sim 0.75 \times 10^{51}$ erg are obtained by 23 and 24 $M_{\odot}$ models, which have the highest compactness among the examined models. These two models exhibit spiral SASI motions during 150-230 ms after bounce preceding a runaway shock expansion and leave a rapidly rotating neutron star with spin periods $\sim 50$ ms. Our models predict the gravitational masses of the neutron star ranging between $1.22 M_{\odot}$ and $1.67 M_{\odot}$ and their spin periods 0.04-4 s. The number distribution of these values roughly matches observation. On the other hand, our models predict small hydrodynamic kick velocity (15-260 km/s), although they are still growing at the end of our simulations. Further systematic studies, including rotation and binary effects, as well as long-term simulations up to several seconds, will enable us to explore the origin of various core-collapse supernova explosions.
Extremely strong magnetic fields of the order of $10^{15}\,{\rm G}$ are required to explain the properties of magnetars, the most magnetic neutron stars. Such a strong magnetic field is expected to play an important role for the dynamics of core-collapse supernovae, and in the presence of rapid rotation may power superluminous supernovae and hypernovae associated to long gamma-ray bursts. The origin of these strong magnetic fields remains, however, obscure and most likely requires an amplification over many orders of magnitude in the protoneutron star. One of the most promising agents is the m…
The magneto-rotational instability (MRI) is considered to be a promising mechanism to amplify the magnetic field in fast rotating protoneutron stars. In contrast to accretion disks, radial buoyancy driven by entropy and lepton fraction gradients is expected to have a dynamical role as important as rotation and shear. We investigate the poorly known impact of buoyancy on the non-linear phase of the MRI, by means of three dimensional numerical simulations of a local model in the equatorial plane of a protoneutron star. The use of the Boussinesq approximation allows us to utilise a shearing box m…
We examine the eigenfrequencies of gravitational waves from the protoneutron stars (PNSs) provided via the core-collapse supernovae, focusing on how the frequencies depend on the dimension of numerical simulations especially for the early phase after core bounce. As expected, we find that the time evolution of gravitational wave frequencies depends strongly on the dimension of numerical simulation as well as the equation of state for high density matter. Even so, we find that the fundamental frequency as a function of PNS average density and the ratio of the specific eigenfrequencies to the fu…
We study the gravitational wave signal from eight new 3D core-collapse supernova simulations. We show that the signal is dominated by $f$- and $g$-mode oscillations of the protoneutron star and its frequency evolution encodes the contraction rate of the latter, which, in turn, is known to depend on the star's mass, on the equation of state, and on transport properties in warm nuclear matter. A lower-frequency component of the signal, associated with the standing accretion shock instability, is found in only one of our models. Finally, we show that the energy radiated in gravitational waves is …
Rotating and magnetized protoneutron stars (PNSs) may drive relativistic magneto-centrifugally accelerated winds as they cool immediately after core collapse. The wind fluid near the star is composed of neutrons and protons, and the neutrons become relativistic while collisionally coupled with the ions. Here, we argue that the neutrons in the flow eventually undergo inelastic collisions around the termination shock inside the stellar material, producing ~0.1-1 GeV neutrinos, without relying on cosmic-ray acceleration mechanisms. Even higher-energy neutrinos may be produced via particle acceler…
The gravitational collapse, bounce, the explosion of an iron core of an 11.2 $M_{\odot}$ star is simulated by two-dimensional neutrino-radiation hydrodynamic code. The explosion is driven by the neutrino heating aided by multi-dimensional hydrodynamic effects such as the convection. Following the explosion phase, we continue the simulation focusing on the thermal evolution of the protoneutron star up to $\sim$70 s when the crust of the neutron star is formed using one-dimensional simulation. We find that the crust forms at high-density region ($ρ\sim10^{14}$ g cm$^{-3}$) and it would proceed f…
We investigate several aspects of black hole formation in failing core-collapse supernovae using 1D general-relativistic hydrodynamic simulations. We use the open-source code GR1D and incorporate into it nucleon-nucleon Bremsstrahlung, a crucial neutrino pair-production channel. We focus on how various thermal effects can influence the postbounce supernova evolution towards black hole formation. By performing simulations with and without nucleon-nucleon Bremsstrahlung, we investigate the sensitivity of black hole formation to thermal support in the protoneutron star. We also investigate delaye…
The magnetorotational instability (MRI) is a promising mechanism to amplify the magnetic field in fast rotating protoneutron stars. The diffusion of neutrinos trapped in the PNS induces a transport of momentum, which can be modelled as a viscosity on length-scales longer than the neutrino mean free path. This neutrino-viscosity can slow down the growth of MRI modes to such an extent that a minimum initial magnetic field strength of $\gtrsim 10^{12}\, {\rm G}$ is needed for the MRI to grow on a sufficiently short time-scale to potentially affect the explosion. It is uncertain whether the magnet…
We examine the time evolution of the frequencies of the gravitational wave after the bounce within the framework of relativistic linear perturbation theory using the results of one dimensional numerical simulations of core-collapse supernovae. Protoneutron star models are constructed in such a way that the mass and radius of protoneutron star become equivalent to the results obtained from the numerical simulations. Then, we find that the frequencies of gravitational waves radiating from protoneutron stars strongly depend on the mass and radius of protoneutron stars, but almost independently of…
We summarize our current understanding of gravitational wave emission from core-collapse supernovae. We review the established results from multi-dimensional simulations and, wherever possible, provide back-of-the-envelope calculations to highlight the underlying physical principles. The gravitational waves are predominantly emitted by protoneutron star oscillations. In slowly rotating cases, which represent the most common type of the supernovae, the oscillations are excited by multi-dimensional hydrodynamic instabilities, while in rare rapidly rotating cases, the protoneutron star is born wi…
In this article the neutrino-pair production from nucleon-nucleon (NN) bremsstrahlung is explored via medium-modifications of the strong interactions at the level of the one-pion exchange approximation. It governs the bulk part of the NN interaction at low densities relevant for the neutrino physics in core-collapse supernova studies. The resulting medium modified one-pion exchange rate for the neutrino-pair processes is implemented in simulations of core collapse supernovae in order to study the impact on the neutrino signal emitted from the deleptonization of the nascent proto-neutron star. …
During a failed core-collapse supernova, the protoneutron star eventually collapses under its own gravitational field and forms a black hole. This collapse happens quickly, on the dynamical time of the protoneutron star, $\lesssim$0.5 ms. During this collapse, barring any excessive rotation, the entire protoneutron star is accreted into the newly formed black hole. The main source of neutrinos is now removed and the signal abruptly shuts off over this formation timescale. However, while the source of neutrinos is turned off, the arrival times at an Earth-based detector will depend on the neutr…
The phase transition from hadronic to quark matter may take place already during the early post-bounce stage of core collapse supernovae when matter is still hot and lepton rich. If the phase transition is of first order and exhibits a barrier, the formation of the new phase occurs via the nucleation of droplets. We investigate the thermal nucleation of a quark phase in supernova matter and calculate its rate for a wide range of physical parameters. We show that the formation of the first droplet of a quark phase might be very fast and therefore the phase transition to quark matter could play …
While it is well known that neutrinos are emitted from standard core collapse protoneutron star supernovae, less attention has been focused on neutrinos from accretion disks. These disks occur in some supernovae (i.e. "collapsars") as well as in compact object mergers, and they emit neutrinos with similar properties to those from protoneutron star supernovae. These disks and their neutrinos play an important role in our understanding of gamma ray bursts as well as the nucleosynthesis they produce. We study a disk that forms in the merger of a black hole and a neutron star and examine the neutr…
To obtain the eigenfrequencies of a protoneutron star (PNS) in the postbounce phase of core-collapse supernovae (CCSNe), we perform a linear perturbation analysis of the angle-averaged PNS profiles using results from a general relativistic CCSN simulation of a $15 M_{\odot}$ star. In this work, we investigate how the choice of the outer boundary condition could affect the PNS oscillation modes in the linear analysis. By changing the density at the outer boundary of the PNS surface in a parametric manner, we show that the eigenfrequencies strongly depend on the surface density. By comparing wit…
Multidimensional simulations show that non-radial, turbulent, fluid motion is a fundamental component of the core-collapse supernova (CCSN) explosion mechanism. Neutrino-driven convection, the standing accretion shock instability, and relic-perturbations from advanced stages of nuclear burning can all impact the outcome of core collapse in a qualitative and quantitative way. Here, we review the current understanding of these phenomena and their role in the explosion of massive stars. We also discuss the role of protoneutron star convection and of magnetic fields in the context of the delayed n…
The release of spin-down energy by a magnetar is a promising scenario to power several classes of extreme explosive transients. However, it lacks a firm basis because magnetar formation still represents a theoretical challenge. Using the first three-dimensional simulations of a convective dynamo based on a protoneutron star interior model, we demonstrate that the required dipolar magnetic field can be consistently generated for sufficiently fast rotation rates. The dynamo instability saturates in the magnetostrophic regime with the magnetic energy exceeding the kinetic energy by a factor of up…
Magnetars are highly magnetized neutron stars whose magnetic dipole ranges from $10^{14}$ to $10^{15}$ G. The MRI is considered to be a promising mechanism to amplify the magnetic field in fast-rotating protoneutron stars and form magnetars. This scenario is supported by many local studies showing that magnetic fields could be amplified by the MRI on small scales. However, the efficiency of the MRI at generating a dipole field is still unknown. To answer this question, we study the MRI dynamo in an idealized global model of a fast rotating protoneutron star with differential rotation. We perfo…
Details of the explosion mechanism of core-collapse supernovae (CCSNe) are not yet fully understood. There is now an increasing number of successful examples of reproducing explosions in the first-principles simulations, which have shown a slow increase of explosion energy. However, it was recently pointed out that the growth rates of the explosion energy of these simulations are insufficient to produce enough $^{56}$Ni mass to account for observations. We refer to this issue as the `nickel mass problem' (Ni problem, hereafter) in this paper. The neutrino-driven wind is suggested as one of the…
A strong bound on the properties of axion-like particles (ALPs) has been set by assuming that ALPs are emitted by the protoneutron star just before the core-bounce in Galactic core-collapse supernovae, and that these ALPs subsequently convert to $γ$-ray photons which ought to be detected by a $γ$-ray mission. This argument has been applied to supernova 1987A to derive the bound on the ALP-photon coupling $g_{a γγ} \lesssim 5.3 \cdot 10^{- 12} \, {\rm GeV}^{- 1}$ for an ALP mass $m_a \lesssim 4.4 \cdot 10^{- 10} \, {\rm eV}$, and can be applied to the next Galactic supernova to derive the even …
We perform general relativistic one-dimensional supernova (SN) simulations to identify observable signatures of enhanced axion emission from the pion-induced reaction $π^- + p \rightarrow n + a$ inside a newly born protoneutron star (PNS).We focus on the early evolution after the onset of the supernova explosion to predict the temporal and spectral features of the neutrino and axion emission during the first 10 s. Pions are included as explicit new degrees of freedom in hot and dense matter. Their thermal population and their role in axion production are both determined consistently to include…
The gravitational-wave (GW) asteroseismology is a powerful technique for extracting interior information of compact objects. In this work, we focus on spacetime modes, the so-called $w$-modes, of GWs emitted from a proto-neutron star (PNS) in the postbounce phase of core-collapse supernovae. Using results from recent three-dimensional supernova models, we study how to infer the properties of the PNS based on a quasi-normal mode analysis in the context of the GW asteroseismology. We find that the $w_1$-mode frequency multiplied by the PNS radius is expressed as a linear function with respect to…
The magnetorotational instability (MRI) can be a powerful mechanism amplifying the magnetic field in core-collapse supernovae. Whether initially weak magnetic fields can be amplified by this instability to dynamically relevant strengths is still a matter of debate. One of the main uncertainties concerns the process that terminates the growth of the instability. Parasitic instabilities of both Kelvin-Helmholtz and tearing-mode type have been suggested to play a crucial role in this process, disrupting MRI channel flows and quenching magnetic field amplification. We perform two-dimensional and t…
Some massive stars end their lives as \textit{failed} core-collapse supernovae (CCSNe) and become black holes (BHs). Although in this class of phenomena the stalled supernova shock is not revived, the outer stellar envelope can still be partially ejected. This occurs because the hydrodynamic equilibrium of the star is disrupted by the gravitational mass loss of the protoneutron star (PNS) due to neutrino emission. We develop a simple model that emulates PNS evolution and its neutrino emission and use it to simulate failed CCSNe in spherical symmetry for a wide range of progenitor stars. Our mo…
Magnetohydrodynamic (MHD) turbulence is of key importance in many high-energy astrophysical systems, where MHD instabilities can amplify local magnetic field over very short time scales. Specifically, the magnetorotational instability (MRI) and dynamo action have been suggested as a mechanism to grow magnetar-strength magnetic field ($\ge10^{15} G$) and magnetorotationally power the explosion of a rotating massive star. Such stars are progenitor candidates for type Ic-bl hypernova explosions and make up all supernovae connected to long gamma-ray bursts (GRBs). The MRI has been studied with loc…
The continuing difficulty of achieving a reliable explosion in simulations of core-collapse supernovae, especially for more massive stars, has led to speculation concerning the observable transients that might be produced if such a supernova fails. Even if a prompt outgoing shock fails to form in a collapsing presupernova star, one must still consider the hydrodynamic response of the star to the abrupt loss of mass via neutrinos as the core forms a protoneutron star. Following a suggestion by Nadezhin (1980), we calculate the hydrodynamical responses of typical supernova progenitor stars to th…
Core-collapse supernovae are accompanied by formation of neutron stars. The gravitation energy is transformed into the energy of the explosion, observed as SN II, SN Ib,c type supernovae. We present results of 2-D MHD simulations, where the source of energy is rotation, and magnetic field serves as a "transition belt" for the transformation of the rotation energy into the energy of the explosion. The toroidal part of the magnetic energy initially grows linearly with time due to differential rotation. When the twisted toroidal component strongly exceeds the poloidal field, magneto-rotational in…
We investigate r-process nucleosynthesis in three-dimensional (3D) general-relativistic magnetohydrodynamic simulations of rapidly rotating strongly magnetized core collapse. The simulations include a microphysical finite-temperature equation of state and a leakage scheme that captures the overall energetics and lepton number exchange due to postbounce neutrino emission and absorption. We track the composition of the ejected material using the nuclear reaction network SkyNet. Our results show that the 3D dynamics of magnetorotational core-collapse supernovae (CCSN) are important for their nucl…
Magnetars are highly magnetized neutron stars that can produce X-ray and soft gamma-ray emissions and that have a dipole of $10^{14}$ G to $10^{15}$ G. A promising mechanism for explaining magnetar formation is magnetic field amplification by the MRI in fast-rotating protoneutron stars (PNS). This scenario is supported by recent global models, which showed that small-scale turbulence can generate a dipole with magnetar-like intensity. However, the impact of buoyancy and density stratification on the efficiency of the MRI in generating a dipole is still unknown. We assess the impact of the dens…
We explore the influence of progenitor mass and rotation on the gravitational-wave (GW) emission from core-collapse supernovae, during the postbounce, preexplosion, accretion-phase. We present the results from 15 two-dimensional (2D) neutrino radiation-hydrodynamic simulations from initial stellar collapse to $\sim$300 ms after core bounce. We examine the features of the GW signals for four zero-age main sequence (ZAMS) progenitor masses ranging from 12 $M_\odot$ to 60 $M_\odot$ and four core rotation rates from 0 to 3 rad s$^{-1}$. We find that GW strain immediately around core bounce is fair…
By performing three-dimensional (3D) simulations that demonstrate the neutrino-driven core-collapse supernovae aided by the standing accretion shock instability (SASI), we study how the spiral modes of the SASI can have impacts on the properties of the gravitational-wave (GW) emission. To see the effects of rotation in the non-linear postbounce phase, we give a uniform rotation on the flow advecting from the outer boundary of the iron core, whose specific angular momentum is assumed to agree with recent stellar evolution models. We compute fifteen 3D models in which the initial angular momentu…
Neutrinos are a guaranteed signal from supernova explosions in the Milky Way, and a most valuable messenger that can provide us with information about the deepest parts of supernovae. In particular, neutrinos will provide us with physical quantities, such as the radius and mass of protoneutron stars (PNS), which are the central engine of supernovae. This requires a theoretical model that connects observables such as neutrino luminosity and average energy with physical quantities. Here, we show analytic solutions for the neutrino-light curve derived from the neutrino radiation transport equatio…
We present results of new three-dimensional (3D) general-relativistic magnetohydrodynamic simulations of rapidly rotating strongly magnetized core collapse. These simulations are the first of their kind and include a microphysical finite-temperature equation of state and a leakage scheme that captures the overall energetics and lepton number exchange due to postbounce neutrino emission. Our results show that the 3D dynamics of magnetorotational core-collapse supernovae are fundamentally different from what was anticipated on the basis of previous simulations in axisymmetry (2D). A strong bipol…
We present the nucleosynthesis of magneto-rotational supernovae (MR-SNe) including neutrino-driven and magneto-rotational-driven ejecta based, for the first time, on 2D simulations with accurate neutrino transport. The models analysed here have different rotation and magnetic fields, allowing us to explore the impact of these two key ingredients. The accurate neutrino transport of the simulations is critical to analyse the slightly neutron-rich and proton-rich ejecta that are similar to the, also neutrino-driven, ejecta in standard supernovae. In the model with strong magnetic field, the r-pro…
We present new 1D (spherical) and 2D (axisymmetric) simulations of electron-capture (EC) and low-mass iron-core-collapse supernovae (SN). We consider six progenitor models: the ECSN progenitor from Nomoto (1984, 1987); two ECSN-like low-mass low-metallicity iron core progenitors from Heger (private communication); and the 9-, 10-, and 11-$M_\odot$ (zero-age main sequence) progenitors from Sukhbold et al. (2016). We confirm that the ECSN and ESCN-like progenitors explode easily even in 1D with explosion energies of up to a 0.15 Bethes ($1 {\rm B} \equiv 10^{51}\ {\rm erg}$), and are a viable me…
Circumstellar Medium of Supernovae as New Probes for Feebly Interacting Particles
Korea Advanced Institute of Science and Technology (KAIST)（韩国科学技术院）；Institute for Basic Science（基础科学研究院）；Academia Sinica（中央研究院）；National Center for Theoretical Sciences（国家理论科学中心）；Kyungpook National University（庆北国立大学）
The mechanism driving core-collapse supernovae is sensitive to the interplay between matter and neutrino radiation. However, neutrino radiation transport is very difficult to simulate, and several radiation transport methods of varying levels of approximation are available. We carefully compare for the first time in multiple spatial dimensions the discrete ordinates (DO) code of Nagakura, Yamada, and Sumiyoshi and the Monte Carlo (MC) code Sedonu, under the assumptions of a static fluid background, flat spacetime, elastic scattering, and full special relativity. We find remarkably good agreeme…
The idea of the magnetorotational explosion mechanism is that the energy of rotation of the neutron star formed in the course of a collapse is transformed into the energy of an expanding shock wave by means of a magnetic field. In the two-dimensional case, the time of this transformation depends weakly on the initial strength of the poloidal magnetic field because of the development of a magnetorotational instability. Differential rotation leads to the twisting and growth of the toroidal magnetic-field component, which becomes much stronger than the poloidal component. In the case where the in…
We have performed a set of 11 three-dimensional magnetohydrodynamical core collapse supernova simulations in order to investigate the dependencies of the gravitational wave signal on the progenitor's initial conditions. We study the effects of the initial central angular velocity and different variants of neutrino transport. Our models are started up from a 15 solar mass progenitor and incorporate an effective general relativistic gravitational potential and a finite temperature nuclear equation of state. Furthermore, the electron flavour neutrino transport is tracked by efficient algorithms f…
We investigated r-process nucleosynthesis in magneto-rotational supernovae, based on a new explosion mechanism induced by the magneto-rotational instability. A series of axisymmetric magneto-hydrodynamical simulations with detailed microphysics including neutrino heating is performed, numerically resolving the magneto-rotational instability. Neutrino-heating dominated explosions, enhanced by magnetic fields, showed mildly neutron-rich ejecta producing nuclei up to $A \sim 130$ (i.e. the weak r-process), while explosion models with stronger magnetic fields reproduce a solar-like r-process patte…
Magnetorotational supernovae are a rare type of core-collapse supernovae where the magnetic field and rotation play a central role in the dynamics of the explosion. We present the post-processed nucleosynthesis of state-of-the-art neutrino-MHD supernova models that follow the post explosion evolution for few seconds. We find three different dynamical mechanisms to produce heavy r-process elements: i) a prompt ejection of matter right after core bounce, ii) neutron-rich matter that is ejected at late times due to a reconfiguration of the protoneutronstar shape, iii) small amount of mass ejected…
We discuss the relevance of the magnetorotational instability (MRI) in core-collapse supernovae (CCSNe). Our recent numerical studies show that in CCSNe, the MRI is terminated by parasitic instabilities of the Kelvin-Helmholtz type. To determine whether the MRI can amplify initially weak magnetic fields to dynamically relevant strengths in CCSNe, we performed three-dimensional simulations of a region close to the surface of a differentially rotating proto-neutron star in non-ideal magnetohydrodynamics with two different numerical codes. We find that under the conditions prevailing in proto-neu…
We present neutrino-transport hydrodynamic simulations of electron-capture supernovae (ECSNe) in \texttt{FLASH} with new two-dimensional (2D) collapsing progenitor models. These progenitor models feature the 2D modelling of oxygen-flame propagation until the onset of core collapse. We perform axisymmetric simulations with 6 progenitor models that, at the time of collapse, span a range of propagating flame front radii. For comparison, we also perform a simulation with the same setup using the canonical, spherically-symmetrical progenitor model n8.8. We found that the variations in the progenito…
We investigated the impacts of magnetorotational instability (MRI) on the dynamics of weakly magnetized, rapidly rotating core-collapse by conducting high resolution MHD simulations in axisymmetry with simplified neutrino transfer. We found that an initially sub-magnetar class magnetic field is drastically amplified by MRI and substantially affects the dynamics thereafter. Although the magnetic pressure is not strong enough to eject matter, the amplified magnetic field efficiently transfers angular momentum from higher to lower latitudes, which causes the expansion of the heating region at low…
We explore explosions of massive stars, which are triggered via the quark-hadron phase transition during the early post bounce phase of core-collapse supernovae. We construct a quark equation of state, based on the bag model for strange quark matter. The transition between the hadronic and the quark phases is constructed applying Gibbs conditions. The resulting quark-hadron hybrid equations of state are used in core-collapse supernova simulations, based on general relativistic radiation hydrodynamics and three flavor Boltzmann neutrino transport in spherical symmetry. The formation of a mixed …
During the core collapse of massive stars, the formation of the protoneutron star is accompanied by the emission of a significant amount of mass-energy ($\sim 0.3 \, M_{\odot}$) in the form of neutrinos. This mass-energy loss generates an outward-propagating pressure wave that steepens into a shock near the stellar surface, potentially powering a weak transient associated with an otherwise-failed supernova. We analytically investigate this mass-loss-induced wave generation and propagation. Heuristic arguments provide an accurate estimate of the amount of energy contained in the outgoing sound …
Gravitational waves from magnetorotational core-collapse supernovae using 3D GRMHD simulations: effect of rotation and magnetic fields
Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理研究所）；University of Amsterdam（阿姆斯特丹大学）；University of Hamburg（汉堡大学）；University of Tennessee（田纳西大学）；GRAPPA, University of Amsterdam（阿姆斯特丹大学引力、暗物质和粒子物理中心）；IoP, University of Amsterdam（阿姆斯特丹大学物理系）；University of British Columbia（不列颠哥伦比亚大学）；National Center for Supercomputing applications, University of Illinois（伊利诺伊大学国家超级计算应用中心）；University of Illinois（伊利诺伊大学）
Circular polarization of gravitational waves from magnetorotational supernovae
Incubator of Scientific Excellence—Centre for Simulations of Superdense Fluids, University of Wrocław（弗罗茨瓦夫大学科学卓越孵化器-超致密流体模拟中心）；Institute of Theoretical Physics, Wrocław University of Science and Technology（弗罗茨瓦夫科技大学理论物理研究所）；National Astronomical Observatory of Japan (NAOJ)（日本国立天文台）；Department of Applied Physics, Fukuoka University（福冈大学应用物理系）；Max-Planck-Institut für Gravitationsphysik（马克斯·普朗克引力物理学研究所）；Research Center for Computational Physics and Data Processing, Institute of Physics, Silesian University in Opava（奥帕瓦西里西亚大学物理研究所计算物理与数据处理研究中心）
Macroscopic evolution of relativistic charged matter with chirality imbalance is described by the chiral magnetohydrodynamics (chiral MHD). One such astrophysical system is high-density lepton matter in core-collapse supernovae where the chirality imbalance of leptons is generated by the parity-violating weak processes. After developing the chiral MHD equations for this system, we perform numerical simulations for the real-time evolutions of magnetic and flow fields, and study the properties of the chiral MHD turbulence. In particular, we observe the inverse cascade of the magnetic energy and …
We present results of three-dimensional (3D), radiation-magnetohydrodynamics (MHD) simulations of core-collapse supernovae in full general relativity (GR) with spectral neutrino transport. In order to study the effects of progenitor's rotation and magnetic fields, we compute three models, where the precollapse rotation rate and magnetic fields are included parametrically to a 20 M$_{\odot}$ star. While we find no shock revival in our two non-magnetized models during our simulation times ($\sim500$ ms after bounce), the magnetorotationally (MR) driven shock expansion immediately initiates after…
We study the role of light nuclear clusters in simulations of core-collapse supernovae. Expressions for the reaction rates are developed for a large selection of charged current absorption and scattering processes with light clusters. Medium modifications are taken into account at the mean-field level. We explore the possible impact on the supernova dynamics and the neutrino signal during the mass accretion phase prior to the possible explosion onset as well as during the subsequent protoneutron star deleptnoization after the explosion onset has been launched.
