We present numerical simulations of the axisymmetric accretion of a massive magnetized plasma torus on a rotating black hole. We use a realistic equation of state, which takes into account neutrino cooling and energy loss due to nucleus dissociations. We simulated various magnetic field configurations and torus models, both optically thick and thin for neutrinos. It is shown that the neutrino cooling does not significantly change either the structure of the accretion flow or the total energy release of the system. The calculations evidence heating of the wind surrounding the collapsar by the shock waves generated at the jet-wind border. This mechanism can give rise to a hot corona around the binary system like SS433.
Angular momentum of the accreting matter defines the time scale of the accretion. Due to the absence of the magnetic dynamo in our calculations, the initial strength and topology of the magnetic field determines magnetization of the black hole, jet formation properties and the total energy yield. We estimated the total energy transformed to jets as $1.3\times 10^{52}$ {ergs} which was sufficient to explain hypernova explosions like GRB 980425 or GRB 030329.
The magnitude of the anomalous torque acting on a rotating magnetized ball in vacuum is specified. Its value is shown to depend on the magnetic field structure inside the body.
Rotating magnetized white dwarfs are studied within the framework of general relativity using Hartle's formalism. Matter inside magnetized white dwarfs is described by an equation of state of particles under the action of a constant magnetic field which introduces anisotropic pressures. Our study is done for values of magnetic field below $10^{13}$ G -a threshold of the maximum magnetic field obtained by the cylindrical metric solution- and typical densities of WDs. The effects of the rotation and magnetic field combined are discussed, we compute relevant magnitudes such as the moment of inert…
The dynamics of a charged relativistic particle in electromagnetic field of a rotating magnetized celestial body with the magnetic axis inclined to the axis of rotation is studied. The covariant Lagrangian function in the rotating reference frame is found. Effective potential energy is defined on the base of the first integral of motion. The structure of the equipotential surfaces for a relativistic charged particle is studied and depicted for different values of the dipole moment. It is shown that there are trapping regions for the particles of definite energies.
Recently a substantial part of globular cluster population has been established as GeV gamma-ray sources by the Fermi-LAT telescope. We investigate possible production of the high energy gamma-rays by relativistic electrons injected from the population of fast rotating, magnetized White Dwarfs within the globular cluster. These electrons comptonize the radiation field within the globular cluster. We conclude that gamma-rays produced by electrons accelerated by the whole population of White Dwarfs within a specific cluster are on the level of detectability of the future Cherenkov telescope arra…
We study oscillations of accretion torus with azimuthal magnetic field. For several lowest-order modes we calculate eigenfrequencies and eigenfunctions and calculate corresponding intensity and polarization light curves using advanced ray-tracing methods.
We calculate the structure and short-term evolution of a gamma ray burst central engine in the form of a turbulent torus accreting onto a stellar mass black hole. Our models apply to the short gamma ray burst events, in which a remnant torus forms after the neutron star-black hole or a double neutron star merger and is subsequently accreted. We study the 2-dimensional, relativistic models and concentrate on the effects of black hole and flow parameters as well as the neutrino cooling. We compare the resulting structure and neutrino emission to the results of our previous 1-dimensional simulati…
Gamma Ray Bursts (GRB) are the extremely energetic transient events, visible from the most distant parts of the Universe. They are most likely powered by accretion on the hyper-Eddington rates that proceeds onto a newly born stellar mass black hole. This central engine gives rise to the most powerful, high Lorentz factor jets that are responsible for energetic gamma ray emission. We investigate the accretion flow evolution in GRB central engine, using the 2D MHD simulations in General Relativity. We compute the structure and evolution of the extremely hot and dense torus accreting onto the fas…
Neutrino-cooled accretion flow around a black hole, produced by a compact binary merger, is a promising scenario for jet formation and magnetic-driven winds to explain short duration gamma ray bursts (GRBs) central engine and kilonovae based on GW170817 gravitational wave observation. Magnetorotational instability (MRI) turbulence and Blandford-Znajek (BZ) mechanism are expected to play key roles in the thermal equilibrium of the disk (balancing neutrino cooling) and in driving accretion and creating jets. Using the open-source GRMHD HARM-COOL code, we study the magnetically-driven evolution o…
Charged particles at the crust of compact stars may be ejected and accelerated by the electric field generated due to the rotation of the magnetized star. For neutron or hybrid stars, the negatively charged particles are usually electrons, and the positively charged particles are mainly protons and Iron. Whereas the existence of strange stars also includes the possibility of ejection of strangelets from the star surface. The flux of such strangelets emitted from all known pulsars is in the range of $10^9-10^{10}$ GeV. Therefore, such massive strangelets can be one of the candidates for the sou…
Highly magnetized neutron stars are promising candidates to explain some of the most peculiar astronomical phenomena, for instance, fast radio bursts, gamma-ray bursts, and superluminous supernovae. Pulsations of these highly magnetized neutron stars are also speculated to produce detectable gravitational waves. In addition, pulsations are important probes of the structure and equation of state of the neutron stars. The major challenge in studying the pulsations of highly magnetized neutron stars is the demanding numerical cost of consistently solving the nonlinear Einstein and Maxwell equatio…
We carry out a linear stability analysis of a magnetized relativistic rotating cylindrical jet flow using the approximation of zero thermal pressure. We identify several modes of instability in the jet: Kelvin-Helmholtz, current driven and two kinds of centrifugal-buoyancy modes -- toroidal and poloidal. The Kelvin-Helmholtz mode is found at low magnetization and its growth rate depends very weakly on the pitch parameter of the background magnetic field and on rotation. The current driven mode is found at high magnetization, the values of its growth rate and the wavenumber, corresponding to th…
We perform a linear stability analysis of magnetized rotating cylindrical jet flows in the approximation of zero thermal pressure. We focus our analysis on the effect of rotation on the current driven mode and on the unstable modes introduced by rotation. We find that rotation has a stabilizing effect on the current driven mode only for rotation velocities of the order of the Alfvén velocity. Rotation introduces also a new unstable centrifugal buoyancy mode and the "cold" magnetorotational instability. The first mode is analogous to the Parker instability with the centrifugal force playing the…
We analyze the torque applied to a rotating magnetized sphere in a vacuum. It is shown that for the correct determination of one of the torque's component the angular momentum of the electromagnetic field within the body should be taken into account.
We confirm recent discovery by Cao that in the vicinity of fast rotating black holes jets can be launched centrifugally by cold, magnetized disks even for nearly vertically shaped magnetic flux surfaces. Outflows produced under such extreme conditions are investigated via studying kinematics of test particles in the force-free magnetosphere approximation. Implications of a possibility of magneto-centrifugal launching of very well collimated central outflows around the fast rotating black holes are discussed in the general context of the jet formation scenarios in AGNs.
We present the global structure of magnetized advective accretion flow around the rotating black holes in presence of dissipation. By considering accretion flow to be threaded by toroidal magnetic fields and by assuming synchrotron radiative mechanism to be the dominant cooling process, we obtain global transonic accretion solutions in terms of dissipation parameters, such as viscosity ($α_B$), accretion rate (${\dot m}$) and plasma-$β$, respectively. In the rotating magnetized accretion flow, centrifugal barrier is developed in the nearby region of the black hole that triggers the discontinuo…
We construct a new three-dimensional general relativistic magnetohydrodynamics code, in which a fixed mesh refinement technique is implemented. To ensure the divergence-free condition as well as the magnetic flux conservation, we employ the method by Balsara (2001). Using this new code, we evolve differentially rotating magnetized neutron stars, and find that a magnetically driven outflow is launched from the star exhibiting a kink instability. The matter ejection rate and Poynting flux are still consistent with our previous finding (Shibata et al., 2011) obtained in axisymmetric simulations.
Evidence for Two SNe Type Triggering GRB 220101A: a Pair SN and a Rotating Magnetized Core Collapse SN
ICRANet（国际相对论天体物理中心网络）；Université de Nice Sophia-Antipolis（尼斯索菲亚安蒂波利斯大学）；INAF（意大利国家天体物理研究所）；Alzahra University（阿尔扎拉大学）；Laboratoire d’Annecy-le-Vieux de Physique Théorique (LAPTh)（阿讷西勒维尤理论物理实验室）；Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室）；University of Tartu（塔尔图大学）；INAF – Osservatorio Astronomico d’Abruzzo（意大利国家天体物理研究所阿布鲁佐天文台）
We study the effects of large scale magnetic fields on the dynamics of charged particles near a rotating black hole. We consider a scenario in which the initially neutral particles on geodesic orbits in the equatorial plane become ionized, and hence they are destabilized by the charging process. Fraction of charged particles are then accelerated out of the equatorial plane and then follow jet like trajectories with relativistic velocities. We explore non axisymmetric systems in which the magnetic field is inclined with respect to the black hole spin. We study the system numerically in order to…
We consider a simple scenario for the accretion of matter onto a neutron star in order to understand processes in the inner pulsar magnetosphere during the transition stage between different accretion modes. A simple quasi-spherical accretion process onto rotating, magnetized compact object is analyzed in order to search for the radiative signatures which could appear during transition between ejecting and accreting modes. It is argued that different accretion modes can be present in a single neutron star along different magnetic field lines for specific range of parameters characterising the …
We study the motion of a charged particle around a weakly magnetized rotating black hole. We classify the fate of a charged particle kicked out from the innermost stable circular orbit. We find that the final fate of the charged particle depends mostly on the energy of the particle and the radius of the orbit. The energy and the radius in turn depend on the initial velocity, the black hole spin, and the magnitude of the magnetic field. We also find possible evidence for the existence of bound motion in the vicinity of the equatorial plane.
We study the two-temperature magnetized advective accretion flow around the Kerr black holes. During accretion, ions are heated up due to viscous dissipation, and when Coulomb coupling becomes effective, they transfer a part of their energy to the electrons. On the contrary, electrons lose energy due to various radiative cooling processes, namely bremsstrahlung, synchrotron, and Comtonization processes, respectively. To account for the magnetic contribution inside the disc, we consider the toroidal magnetic fields which are assumed to be dominant over other components. Moreover, we adopt the r…
We studied roles of a turbulent resistivity in the core-collapse of a strongly magnetized massive star, carrying out 2D-resistive-MHD simulations. The three cases with different initial strengths of magnetic field and rotation are investigated; 1. strongly magnetized rotating core; 2.moderately magnetized rotating core; 3. very strongly magnetized non-rotating core. In each case, both an ideal-MHD model and resistive-MHD models are computed. As a result of computations, each model shows a matter eruption helped by a magnetic acceleration (and also by a centrifugal acceleration in the rotating …
Context. The supermassive black hole, Sagittarius (Sgr) A*, in the centre of our Galaxy has the largest angular size in the sky among all astrophysical black holes. Its shadow, assuming no rotation, spans ~ 50 microarcsec. Resolving such dimensions has long been out of reach for astronomical instruments until a new generation of interferometers being operational during this decade. Of particular interest is the Event Horizon Telescope (EHT) with resolution ~ 20 microarcsec in the millimeter-wavelength range 0.87 mm - 1.3 mm. Aims. We investigate the ability of the fully general relativistic Ko…
The close neighbourhood of a supermassive black hole contains not only the accreting gas and dust but also stellar-sized objects, such as late-type and early-type stars and compact remnants that belong to the nuclear star cluster. When passing through the accretion flow, these objects perturb it by the direct action of stellar winds, as well as their magnetic and gravitational effects. By performing General-Relativistic Magnetohydrodynamic (GRMHD) simulations, we investigate how the passages of a star can influence the supermassive black hole gaseous environment. We focus on the changes in the…
We describe one of the so-called low magnetic field magnetars SGR 0418+5729, as a massive fast rotating highly magnetized white dwarf following Malheiro et. al. 2012. We give bounds for the mass, radius, moment of inertia, and magnetic field for these sources, by requesting the stability of realistic general relativistic uniformly rotating configurations. Based on these parameters, we improve the theoretical prediction of the lower limit of the spin-down rate of SGR 0418+5729. In addition, we compute the electron cyclotron frequencies corresponding to the predicted surface magnetic fields.
Electromagnetic waves arise in many area of physics. Solutions are difficult to find in the general case. In this paper, we numerically integrate Maxwell equations in a 3D spherical polar coordinate system. Straightforward finite difference methods would lead to a coordinate singularity along the polar axis. Spectral methods are better suited to deal with such artificial singularities related to the choice of a coordinate system. When the radiating object is rotating like for instance a star, special classes of solutions to Maxwell equations are worthwhile to study such as quasi-stationary reg…
Isolated pulsars are rotating neutron stars with accurately measured angular velocities $Ω$, and their time derivatives which show unambiguously that the pulsars are slowing down. Although the exact mechanism of the spin-down is a question of debate in detail, the commonly accepted view is that it arises through emission of magnetic dipole radiation (MDR) from a rotating magnetized body. Other processes, including the emission of gravitational radiation, and of relativistic particles (pulsar wind), are also being considered. The calculated energy loss by a rotating pulsar with a constant momen…
A numerical study of the dynamic of the nonselfgravitating, unmagnetized, nonaxisymmetric, and rotating the torus around the non-rotating black hole is presented. We investigate the instability of the rotating torus subject to perturbations presented by increasing or decreasing the angular velocity of the stable torus. We have done, for the first time, an extensive analysis of the torus dynamic response to the perturbation of the angular velocity of the stable torus. We show how the high, moderate, and low values of the perturbations affect the torus dynamic and help us to understand the prope…
We study how axisymmetric magnetohydrodynamical (MHD) accretion flows depend on gamma adiabatic index in the polytropic equation of state. This work is an extension of Moscibrodzka & Proga (2008), where we investigated the gamma dependence of 2-D Bondi-like accretion flows in the hydrodynamical (HD) limit. Our main goal is to study if simulations for various gamma can give us insights into to the problem of various modes of accretion observed in several types of accretion systems such as black hole binaries (BHB), active galactic nuclei (AGN), and gamma-ray bursts (GRBs). We find that for gamm…
Supermassive stars (SMSs) of mass $\gtrsim 10^5 M_\odot$ are candidates for seeds of supermassive black holes found in the center of many massive galaxies. We simulate the gravitational collapse of a rigidly rotating SMS core including nuclear burning effects in axisymmetric numerical-relativity simulation. We find that for realistic initial conditions, the nuclear burning does not play an important role. After the collapse, a torus surrounding a rotating black hole is formed and a fraction of the torus material is ejected. We quantitatively study the relation between the properties of these o…
There is solid observational evidence on the existence of massive, $M\sim 1~M_\odot$, highly magnetized white dwarfs (WDs) with surface magnetic fields up to $B\sim 10^9$ G. We show that, if in addition to these features, the star is fast rotating, it can become a rotation-powered pulsar-like WD and emit detectable high-energy radiation. We infer the values of the structure parameters (mass, radius, moment of inertia), magnetic field, rotation period and spin-down rates of a WD pulsar death-line. We show that WDs above the death-line emit blackbody radiation in the soft X-ray band via the magn…
The field of a uniformly magnetized rotating sphere is studied with special attention to the surface where the electric and magnetic fields are orthogonal to each other. The equation of this surface, valid at arbitrary distances from the rotating magnetized sphere, is obtained. Inside the light cylinder this surface can be considered as a force-free surface, i.e. as a place where the particles with strong radiation damping can be trapped due to their energy loss. Outside the light cylinder this surface makes just a geometric locus which moves with a superlight velocity around the axis of rotat…
As evidenced by the coincident detections of GW170817 and GRB 170817A, short gamma-ray bursts are likely associated with neutron star-neutron star merger events. Although rare, some bursts display episodes of early emission, with precursor flares being observed up to $\sim 10$ seconds prior to the main burst. As the stars inspiral due to gravitational wave emission, the exertion of mutual tidal forces leads to the excitation of stellar oscillation modes, which may come into resonance with the orbital motion. Mode amplitudes increase substantially during a period of resonance as tidal energy is…
We study non-geodesic corrections to the quasicircular motion of charged test particles in the field of magnetized slowly rotating neutron stars. The gravitational field is approximated by the Lense-Thirring geometry, the magnetic field is of the standard dipole character. Using a fully-relativistic approach we determine influence of the electromagnetic interaction (both attractive and repulsive) on the quasicircular motion. We focus on the behaviour of the orbital and epicyclic frequencies of the motion. Components of the four-velocity of the orbiting charged test particles are obtained by nu…
We explore the formation process of a black hole (BH) through the pair-instability collapse of a rotating Population III very massive star in axisymmetric numerical relativity. As the initial condition, we employ a progenitor star which is obtained by evolving a rapidly rotating zero-age main sequence (ZAMS) star with mass $320M_\odot$ until it reaches a pair instability region. We find that for such rapidly rotating model, a fraction of the mass, $\sim 10M_\odot$, forms a torus surrounding the remnant BH of mass $\sim 130M_\odot$ and an outflow is driven by a hydrodynamical effect. We also pe…
Plasma magnetosphere surrounding rotating magnetized neutron star in the braneworld has been studied. For the simplicity of calculations Goldreich-Julian charge density is analyzed for the aligned neutron star with zero inclination between magnetic field and rotation axis. From the system of Maxwell equations in spacetime of slowly rotating star in braneworld, second-order differential equation for electrostatic potential is derived. Analytical solution of this equation indicates the general relativistic modification of an accelerating electric field and charge density along the open field lin…
Laplace-Fourier linear stability analysis of non-relativistic magnetized rotational jets: mode identification by Hamiltonian analysis and the occurrence of mode transitions
A new code for computing fully general relativistic solutions of strongly magnetized rapidly rotating compact stars is developed as a part of the COCAL (Compact Object CALculator) code. The full set of Einstein's equations, Maxwell's equations and magnetohydrodynamic equations are consistently solved assuming perfect conductivity, stationarity, and axisymmetry, and strongly magnetized solutions associated with mixed poloidal and toroidal components of magnetic fields are successfully obtained in generic (non-circular) spacetimes. We introduce the formulation of the problem and the numerical me…
We investigate the evolution of isolated, zero and finite temperature, massive, uniformly rotating and highly magnetized white dwarf stars under angular momentum loss driven by magnetic dipole braking. We consider the structure and thermal evolution of white dwarf isothermal cores taking also into account the nuclear burning and neutrino emission processes. We estimate the white dwarf lifetime before it reaches the condition either for a type Ia supernova explosion or for the gravitational collapse to a neutron star. We study white dwarfs with surface magnetic fields from $10^6$ to $10^{9}$~G …
General-relativistic resistive-magnetohydrodynamics simulations of self-consistent magnetized rotating neutron stars
University of New Hampshire（新罕布什尔大学）；Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室）；University of California, Berkeley（加州大学伯克利分校）；University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）；National Center for Supercomputing Applications, University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校超级计算应用国家中心）；Academy of Athens（雅典科学院）；Universitat de Valéncia（瓦伦西亚大学）；Niels Bohr International Academy, Niels Bohr Institute（尼尔斯·玻尔国际学院，尼尔斯·玻尔研究所）；The Chinese University of Hong Kong（香港中文大学）；University of the Ryukyus（冲绳大学）
In this work we compute models for relativistic white dwarfs in the presence of strong magnetic fields. These models possibly contribute to super-luminous SNIa. With an assumed axi-symmetric and poloidal magnetic field, we study the possibility of existence of super-Chandrasekhar magnetized white dwarfs by solving numerically the Einstein-Maxwell equations, by means of a pseudo-spectral method. We obtain a self-consistent rotating and non-rotating magnetized white dwarf models. According to our results, a maximum mass for a static magnetized white dwarf is 2.13 $\rm{M_{\odot}}$ in the Newtonia…
We present three-dimensional simulations of the dynamical bar-mode instability in magnetized and differentially rotating stars in full general relativity. Our focus is on the effects that magnetic fields have on the dynamics and the onset of the instability. In particular, we perform ideal-magnetohydrodynamics simulations of neutron stars that are known to be either stable or unstable against the purely hydrodynamical instability, but to which a poloidal magnetic field in the range of $10^{14}$--$10^{16}$ G is superimposed initially. As expected, the differential rotation is responsible for th…
We investigate how magnetically driven outflows are powered by a rotating, weakly magnetized accretion flow onto a supermassive black hole using axisymmetric magnetohydrodynamic simulations. Our proposed model focuses on the accretion dynamics on an intermediate scale between the Schwarzschild radius and the galactic scale, which is $\sim$1-100 pc. We demonstrate that a rotating disk formed on a parsec-scale acquires poloidal magnetic fields via accretion and this produces an asymmetric bipolar outflow at some point. The formation of the outflow was found to follow the growth of strongly magne…
We study the magnetosphere of a slowly rotating magnetized neutron star subject to toroidal oscillations in the relativistic regime. Under the assumption of a zero inclination angle between the magnetic moment and the angular momentum of the star, we analyze the Goldreich-Julian charge density and derive a second-order differential equation for the electrostatic potential. The analytical solution of this equation in the polar cap region of the magnetosphere shows the modification induced by stellar toroidal oscillations on the accelerating electric field and on the charge density. We also find…
AE Aquarii is a cataclysmic variable with the fastest known rotating magnetized white dwarf (P_spin = 33.08 s). Compared to many intermediate polars, AE Aquarii shows a soft X-ray spectrum with a very low luminosity (L_X ~ 10^{31} erg/s). We have analyzed overlapping observations of this system with the NuSTAR and the Swift X-ray observatories in September of 2012. We find the 0.5-30 keV spectra to be well fitted by either an optically thin thermal plasma model with three temperatures of 0.75 +0.18 -0.45, 2.29 +0.96 -0.82, and 9.33 +6.07 -2.18 keV, or an optically thin thermal plasma model wit…
By exploiting the extreme environment of the black hole (BH) as a potential place for axion-photon interaction, we use an axion-producing model of the magnetized plasma to study the shadow of an asymptotically flat rotating BH immersed into an axion-plasmon cloud. By aiming to reveal footprints of axion in the dark shadow of BH, we in this paper explore the influence of the fixed axion-plasmon background on the motion of incident photons around the rotating BH. Under some free parameter settings, we find that axion-plasmon cloud around rotating BH affects the shape and size of the shadow in su…
We investigate non-axisymmetric low frequency modes of a rotating and magnetized neutron star, assuming that the star is threaded by a dipole magnetic field whose strength at the stellar surface, $B_0$, is less than $\sim 10^{12}$G, and whose magnetic axis is aligned with the rotation axis. For modal analysis, we use a neutron star model composed of a fluid ocean, a solid crust, and a fluid core, where we treat the core as being non-magnetic assuming that the magnetic pressure is much smaller than the gas pressure in the core. Here, we are interested in low frequency modes of a rotating and ma…
One of the methods of study of black holes in astrophysics is based on broadening of the spectrum of radiation of ionized Iron atoms. The line K$α$ associated with Iron emission at 6.4 keV is very narrow. If such an ion is revolving around a black hole, this line is effectively broadened as a result of the Doppler and gravitational redshift effects. The profile of the broaden spectrum contains information about the gravitational field of the black hole. In the presence of a regular magnetic field in the vicinity of a black holes the characteristics of the motion of charged ions are modified. I…
We study neutrinos gravitationally scattered off a rotating supermassive black hole which is surrounded by a thin accretion disk with a realistic magnetic field. Neutrinos are supposed to be Dirac particles having a nonzero magnetic moment. Neutrinos move along arbitrary trajectories, with the incoming flux being parallel to the equatorial plane. We exactly account for the influence of both gravity and the magnetic field on the neutrino motion and its spin evolution. The general statement that the helicity of an ultrarelativistic neutrino is constant in the particle scattering in an arbitrary …
Black hole-torus systems from compact binary mergers are possible engines for gamma-ray bursts (GRBs). During the early evolution of the post-merger remnant, the state of the torus is determined by a combination of neutrino cooling and magnetically-driven heating processes, so realistic models must include both effects. In this paper, we study the post-merger evolution of a magnetized black hole-neutron star binary system using the Spectral Einstein Code (SpEC) from an initial post-merger state provided by previous numerical relativity simulations. We use a finite-temperature nuclear equation …
We study collision of particles in the vicinity of a horizon of a weakly magnetized non-rotating black hole. In the presence of the magnetic field innermost stable circular orbits (ISCO) of charged particles can be located close to the horizon. We demonstrate that for a collision of two particles, one of which is charged and revolving at ISCO and the other is neutral and falling from infinity, the maximal collision energy can be high in the limit of strong magnetic field. This effect has some similarity with the recently discussed effect of high center-of-mass energy for collision of particles…
The evolution of the remnant of the merger of two white dwarfs is still an open problem. Furthermore, few studies have addressed the case in which the remnant is a magnetic white dwarf with a mass larger than the Chandrasekhar limiting mass. Angular momentum losses might bring the remnant of the merger to the physical conditions suitable for developing a thermonuclear explosion. Alternatively, the remnant may be prone to gravitational or rotational instabilities, depending on the initial conditions reached after the coalescence. Dipole magnetic braking is one of the mechanisms that can drive s…
Type Ia supernovae (SNe Ia) play a crucial role as standardizable cosmological candles, though the nature of their progenitors is a subject of active investigation. Recent observational and theoretical work has pointed to merging white dwarf binaries, referred to as the double-degenerate channel, as the possible progenitor systems for some SNe Ia. Additionally, recent theoretical work suggests that mergers which fail to detonate may produce magnetized, rapidly-rotating white dwarfs. In this paper, we present the first multidimensional simulations of the post-merger evolution of white dwarf bin…
