We study the thermal and chemical evolution during Kelvin-Helmholtz phase of birth a neutron star, employing neutrino opacities that are consistently calculated with underlying equation state (EOS). Expressions for diffusion coefficients appropriate general relativistic transport in equilibrium approximation derived. The evaluated using field-theoretical finite-temperature EOS includes possible presence hyperons. variation is studied as function compositional parameters. present results from...

Observations of magnetars and some the high magnetic field pulsars have shown that their thermal luminosity is systematically higher than classical radio-pulsars, thus confirming idea fields are involved in X-ray emission. Here we present results 2D simulations fully-coupled evolution temperature neutron stars, including state-of-the-art kinetic coefficients and, for first time, important effect Hall term. After gathering thoroughly re-analysing a consistent way all best available data on...

We present a general procedure to solve numerically the three-dimensional relativistic hydrodynamic system of equations within framework {3 + 1} formalism. The are written in conservation form exploit their hyperbolic character. derive theoretical ingredients that necessary order build up numerical scheme based on solution local Riemann problems. Hence spectral decomposition Jacobian matrices system, i.e., eigenvalues and eigenvectors, is explicitly shown. have taken advantage analytic...

<i>Context. <i/>The presence of magnetic fields in the crust neutron stars (NSs) causes a non-spherically symmetric temperature distribution. The strong dependence diffusivity and thermal conductivity, together with heat generated by dissipation, couple evolution NSs, which can no longer be formulated as separated one-dimensional problems. <i>Aims. <i/>We study mutual influence star's axial symmetry. Taking realistic microphysical inputs into account, we find released Joule effect consistent...

We perform population synthesis studies of different types neutron stars (thermally emitting isolated stars, normal radio pulsars, magnetars) taking into account the magnetic field decay and using results from most recent advances in star cooling theory. For first time, we confront our with observations {\it simultaneously} Log N -- S distribution for nearby L magnetars, pulsars $P$ $\dot P$ diagram. this purpose, fix a baseline model (all microphysics input), other relevant parameters to...

We present a general procedure to solve numerically the relativistic magnetohydrodynamics (GRMHD) equations within framework of 3+1 formalism. The work reported here extends our previous investigation in hydrodynamics (Banyuls et al. 1997) where magnetic fields were not considered. GRMHD are written conservative form exploit their hyperbolic character solution procedure. All theoretical ingredients necessary build up high-resolution shock-capturing schemes based on local Riemann problems...

We extend some recent shock capturing methods designed to solve nonlinear hyperbolic systems of conservation laws and which avoid the use artificial viscosity for treating strong discontinuities a relativistic hydrodynamics system equations. Some standard shock-tube problems radial accretion onto Schwarzschild black hole are used calibrate our code.

We present numerical simulations of the spectral evolution and emission radio components in relativistic jets. compute jet models by means a hydrodynamics code. have developed an algorithm (SPEV) for transport population nonthermal electrons including radiative losses. For large values ratio gas pressure to magnetic field energy density, αB ∼ 6 × 104, quiescent show substantial evolution, with observational consequences only above frequencies. Larger (αB 102), such that synchrotron losses...

Context: Many thermally emitting isolated neutron stars have magnetic fields larger than 10^13 G. A realistic cooling model that includes the presence of high should be reconsidered. Aims: We investigate effects anisotropic temperature distribution and Joule heating on magnetized stars. Methods: The 2D heat transfer equation with thermal conductivity tensor including all relevant neutrino emission processes is solved for models star interior crust. Results: field affects significantly...

The impact of strong magnetic fields B>10e13 G on the thermal evolution neutron stars is investigated, including crustal heating by field decay. For this purpose, we perform 2D cooling simulations with anisotropic conductivity considering all relevant neutrino emission processes for realistic stars. standard models are called into question showing that has (and in many cases dominant) effects evolution. presence significantly affects surface distribution and history these objects during...

We revisit the population synthesis of isolated radio-pulsars incorporating recent advances on evolution magnetic field and angle between rotational axes from new simulations magneto-thermal magnetosphere models, respectively. An interesting novelty in our approach is that we do not assume existence a death line. discuss regions parameter space are more consistent with observational data. In particular, find any broad distribution birth spin periods $P_0\lesssim 0.5$ s can fit data, if...

We have performed a comprehensive parameter study of the morphology and dynamics axisymmetric, magnetized, relativistic jets by means numerical simulations. The simulations been with an upgraded version GENESIS code which is based on second-order accurate finite volume method involving approximate Riemann solver suitable for ideal magnetohydrodynamic flows, lines. Starting from pure hydrodynamic models we consider effect magnetic field increasing strength (up to times equipartition value)...

We study ambipolar diffusion in strongly magnetized neutron stars, with special focus on the effects of neutrino reaction rates and impact a superfluid/superconducting transition star core. For axisymmetric magnetic field configurations, we determine deviation from β-equilibrium induced by force calculate velocity slow, quasi-stationary, drift. temperature dependence pattern clearly identify to predominantly solenoidal flow. stars without superconducting/superfluid constituents mixed...

We show the existence of a strong trend between neutron star (NS) surface temperature and dipolar component magnetic field extending through three orders magnitude, range that includes magnetars, radio-quiet isolated stars, many ordinary radio pulsars. suggest this can be explained by decay currents in crust over time scale approximately 10(6) yr. estimate minimum NS with given reach interpretation.

Population synthesis studies constitute a powerful method to reconstruct the birth distribution of periods and magnetic fields pulsar population. When this is applied populations in different wavelengths, it can break degeneracy inferred properties initial distributions that arises from single-band studies. In context, we extend previous works include $X$-ray thermal emitting pulsars within same evolutionary model as radio-pulsars. We find cumulative number X-ray be well reproduced by...

A large fraction of Gamma Ray Bursts (GRBs) displays an X-ray plateau phase within <10^{5} s from the prompt emission, proposed to be powered by spin-down energy a rapidly spinning newly born magnetar. In this work we use properties Galactic neutron star population constrain GRB-magnetar scenario. We re-analyze plateaus all Swift GRBs with known redshift, between January 2005 and August 2014. From derived initial magnetic field distribution for possible magnetars left behind GRBs, study...

Context.The thermal emission from isolated neutron stars is not well understood. The X-ray spectrum very close to a blackbody but there systematic optical excess flux with respect the extrapolation low energy of best fit. This fact, in combination observed pulsations flux, can be explained by anisotropies surface temperature distribution.

We obtain renormalized sets of right and left eigenvectors the flux vector Jacobians relativistic MHD equations, which are regular span a complete basis in any physical state including degenerate ones. The renormalization procedure relies on characterization degeneracy types terms normal tangential components magnetic field to wavefront fluid rest frame. Proper expressions conserved variables obtained through corresponding matrix transformations. Our work completes previous analysis that...

We study the coupling of force-free magnetosphere to long-term internal evolution a magnetar. allow relation between poloidal and toroidal stream functions - that characterizes evolve freely without constraining its particular form. find that, on time-scales order kyr, energy stored in gradually increases, as region grows field lines expand outwards. This continues until critical point is reached beyond which solutions for can no longer be constructed, likely leading some large-scale...

We revisit the various approximations employed to study long-term evolution of magnetic field in neutron star cores and discuss their limitations possible improvements. A recent controversy on correct form induction equation relevant timescale superconducting is addressed clarified. show that this ambiguity estimation timescales arises as a consequence nominally large terms appear equation, but which are, fact, mostly irrotational. This subtlety leads discrepancy by many orders magnitude...

view Abstract Citations (63) References (48) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A New Spherically Symmetric General Relativistic Hydrodynamical Code Romero, Jose V. ; Ibanez, M. A. Marti, Miralles, Juan In this paper we present a full general relativistic one-dimensional hydrocode which incorporates modern high-resolution shock-capturing algorithm, with an approximate Riemann solver, for the correct modeling of formation and propagation strong...

We present simulations of the evolution a proto-neutron star in which kaon-condensed matter might exist, including effects finite temperature and trapped neutrinos. The phase transition from pure nucleonic to kaon condensate is described using Gibbs' rules for equilibrium, permit existence mixed phase. A general property neutron stars containing condensates, as well other forms strangeness, that maximum mass cold, neutrino-free can be less than neutrinos or has entropy. formed with baryon...

We investigate the thermal emission from magnetic neutron star surfaces in which cohesive effects of field have produced condensation atmosphere and external layers. This may happen for sufficiently cool atmospheres with moderately intense fields. The an isothermal bare surface a shows no remarkable spectral features, but it is significantly depressed at energies below some threshold energy. However, since conductivity very different normal parallel directions to lines, presence expected...

Certain aspects of the (linear and nonlinear) stability sheared relativistic (slab) jets are analyzed. The linear problem has been solved for a wide range jet models well inside ultrarelativistic domain (flow Lorentz factors up to 20, specific internal energies approximately 60c2). As distinct feature our work, we have combined analytical approach with high-resolution hydrodynamical simulations, which allowed us (i) identify, in regime, resonant modes shear layer, (ii) confirm result...