A5067690939- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Geophysics and Gravity Measurements
- High-pressure geophysics and materials
- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Black Holes and Theoretical Physics
- Solar and Space Plasma Dynamics
- Magnetic confinement fusion research
- Astro and Planetary Science
- Relativity and Gravitational Theory
- Spacecraft and Cryogenic Technologies
- High-Energy Particle Collisions Research
- Advanced Chemical Physics Studies
- Stellar, planetary, and galactic studies
- Advanced Thermodynamics and Statistical Mechanics
- Ionosphere and magnetosphere dynamics
- Nonlinear Waves and Solitons
- Cold Atom Physics and Bose-Einstein Condensates
- Geophysics and Sensor Technology
- Seismic Waves and Analysis
- Computational Physics and Python Applications
- Mathematical functions and polynomials
Universidade Federal do ABC
2011-2024
Universidade Estadual de Campinas (UNICAMP)
1998-2005
We present new (3+1)D numerical relativity simulations of the binary neutron star (BNS) merger and postmerger phase. focus on a previously inaccessible region parameter space spanning binary's mass-ratio $q\sim1.00-1.75$ for different total masses equations state, up to $q\sim2$ stiff BNS system. study effect gravitational waves (GWs) possible electromagnetic emission associated dynamical mass ejecta. compute waveforms, spectra, spectrograms GW strain including all multipoles $l=4$. The has...
In addition to the emission of gravitational waves (GWs) coalescence and merger two neutron stars will produce a variety electromagnetic (EM) signals. this work we combine large set numerical relativity simulations performed by different groups present fits for mass, kinetic energy, velocities dynamical ejected material. Additionally, comment on geometry composition ejecta discuss influence stars' individual rotation. The derived can be used approximate luminosity lightcurve kilonovae...
We study equal- and unequal-mass neutron star mergers by means of new numerical relativity simulations in which the general relativistic hydrodynamics solver employs an algorithm that guarantees mass conservation across refinement levels computational mesh. consider eight binary configurations with total $M=2.7{M}_{\ensuremath{\bigodot}}$, ratios $q=1$ $q=1.16$, four different equations state (EOSs) one configuration a stiff EOS, $M=2.5{M}_{\ensuremath{\bigodot}}$ $q=1.5$, is largest...
Binary neutron star mergers are studied using nonlinear 3+1 numerical relativity simulations and the analytical effective-one-body (EOB) model. The EOB model predicts quasiuniversal relations between mass-rescaled gravitational wave frequency binding energy at moment of merger, certain dimensionless binary tidal coupling constants depending on stars Love numbers, compactnesses mass ratio. These in sense that, for a given value constant, they depend significantly neither equation state nor...
We present the computational relativity (CoRe) collaboration's public database of gravitational waveforms from binary neutron star mergers. The currently contains 367 numerical simulations that are consistent with general and employ constraint satisfying initial data in hydrodynamical equilibrium. It spans 164 physically distinct configuration different parameters (total mass, mass-ratio, separation, eccentricity, stars' spins) simulated physics. Waveforms computed at multiple grid...
Abstract We present the second data release of gravitational waveforms from binary neutron star (BNS) merger simulations performed by Computational Relativity ( CoRe ) collaboration. The current database consists 254 different BNS configurations and a total 590 individual numerical-relativity using various grid resolutions. released waveform contain strain Weyl curvature multipoles up to <?CDATA $\ell = m 4$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...
For the analysis of gravitational-wave signals, fast and accurate gravitational-waveform models are required. These enable us to obtain information on system properties from compact binary mergers. In this article, we introduce model, which contains a closed-form expression that describes tidal effects, focusing description neutron star systems. The model improves upon previous versions by employing larger set numerical-relativity data for its calibration, including high-mass ratio systems...
A crucial ingredient in accurate simulations of neutron star-neutron star and star-black hole mergers is the inclusion neutrino transport its effects on physics astrophysics these phenomena. The authors implement a radiative scheme their general relativistic hydrodynamics code, BAM, do more accurately simulate map ejecta from mergers.
We present new (3+1) dimensional numerical relativity simulations of the binary neutron star (BNS) mergers that take into account NS spins. consider different spin configurations, aligned or antialigned to orbital angular momentum, for equal and unequal mass BNS two equations state. All employ quasiequilibrium circular initial data in constant rotational velocity approach, i.e. they are consistent with Einstein hydrodynamical equilibrium. study rotation effect on energetics, gravitational...
The next observing runs of advanced gravitational-wave detectors will lead to a variety binary neutron star detections and numerous possibilities for multi-messenger observations systems. In this context clear understanding the merger process possibility prompt black hole formation after is important, as amount ejected material strongly depends on dynamics. These dynamics are primarily affected by total mass binary, however, ratio also influences postmerger evolution. To determine effect...
Accurate numerical-relativity simulations are essential to study the rich phenomenology of binary neutron star systems. In this work, we focus on material that is dynamically ejected during merger process and kilonova transient it produces. Typically, radiative transfer light curves from ejecta make assumption homologous expansion, but condition might not always be met at end usually very short simulations. article, adjust infrastructure BAM code enable longer dynamical with aim...
As current gravitational wave (GW) detectors increase in sensitivity, and particularly as new instruments are being planned, there is the possibility that ground-based GW will observe GWs from highly eccentric neutron star binaries. We present first detailed study of BNS systems with full (3+1)D numerical relativity simulations using consistent initial conditions, i.e., setups which agreement Einstein equations general relativistic hydrodynamics equilibrium. Overall, our cover two different...
With the increasing sensitivity of advanced gravitational wave detectors, first joint detection an electromagnetic and signal from a compact binary merger will hopefully happen within this decade. However, current gravitational-wave likelihood sky areas span $\sim 100-1000\,\textrm{deg}^2$, thus it is challenging task to identify which, if any, transient corresponds event. In study, we make comparison between recent kilonovae/macronovae lightcurve models for purpose assessing potential...
Over the last few years, there has been an increasing interest in sub-solar-mass black holes due to their potential provide valuable information about cosmology or hole population. Motivated by this, we study observable phenomena connected merger of a with neutron star. For this purpose, perform new numerical-relativity simulations binary system composed mass $0.5{M}_{\ensuremath{\bigodot}}$ and star $1.4{M}_{\ensuremath{\bigodot}}$. We investigate dynamics exotic gravitational-wave kilonova...
We present the first set of numerical relativity simulations binary neutron mergers that include spin precession effects and are evolved with multiple resolutions. Our employ consistent initial data in general different configurations dimensionless magnitudes $\ensuremath{\sim}0.1$. They start at a gravitational-wave frequency $\ensuremath{\sim}392\text{ }\text{ }\mathrm{Hz}$ cover more than 1 period about 15 orbits up to merger. discuss dynamics by analyzing coordinate trajectories,...
Multimessenger observations of binary neutron-star mergers provide a unique opportunity to constrain the dense-matter equation state. Although it is known from quantum chromodynamics that hadronic matter will undergo phase transition exotic forms matter---e.g., quark matter---the onset density such cannot be computed first principles. Hence, remains an open question if transitions occur inside isolated neutron stars or during mergers, they appear at even higher densities are not realized in...
Abstract The equation of state (EOS) dense strongly interacting matter can be probed by astrophysical observations neutron stars (NS), such as X-ray detections pulsars or the measurement tidal deformability NSs during inspiral stage NS mergers. These constrain EOS at most up to density maximum-mass configuration, n TOV , which is highest that explored stable for a given EOS. However, under right circumstances, binary star (BNS) mergers create postmerger remnant explores densities above . In...
Accurate modeling of the multimessenger signatures connected to binary neutron star mergers requires proper knowledge on final remnant's fate and conditions under which black holes (BHs) can form in such mergers. In this article, we use a suite 84 numerical-relativity simulations 28 different physical setups explore impact individual stars' spin merger outcome early postmerger dynamics. We find that for close prompt-collapse threshold, intrinsic significantly changes lifespan remnant before...
The gravitational wave and electromagnetic signatures connected to the merger of two neutron stars allow us test nature matter at supranuclear densities. Since Equation State governing interior is only loosely constrained, there even possibility that strange quark exists inside core stars. We investigate how cores affect binary star coalescence by performing numerical relativity simulations. Interestingly, strong phase transition can cause a reduction convergence order schemes first if...
Numerical studies of the dynamics gravitational systems, e.g., black hole-neutron star require physical and constraint-satisfying initial data. In this article, we present newly developed pseudo-spectral code Elliptica, an infrastructure for construction data various binary single systems all kinds. The elliptic equations under consideration are solved on a spatial hypersurface spacetime manifold. Using coordinate maps, is covered by patches whose boundaries can adapt to surface compact...
The high-accuracy determination of trace metals in biological systems is a crucial step for the elucidation their role these systems.
We continue our study of the binary neutron star parameter space by investigating effect spin orientation on dynamics, gravitational wave emission, and mass ejection during coalescence. simulate seven different configurations using multiple resolutions to allow a reasonable error assessment. Due particular choice setups, five show precession effects, from which two (``wobbling'') orbital plane, while three ``bobbing'' motion; i.e., angular momentum does not precess, plane moves along axis....
The stability of general relativistic thin disks is investigated under a first order perturbation the energy momentum tensor. In particular, we consider temporal, radial, and azimuthal ``test matter'' perturbations quantities involved on plane $z=0$. We study generated by applying ``displace, cut, reflect'' method, usually known as image to Schwarzschild metric in isotropic coordinates Chazy-Curzon Zipoy-Voorhees ($\ensuremath{\gamma}$-metric) Weyl coordinates. case disk, where radial...