scholarly journals Three-dimensional general-relativistic hydrodynamic simulations of binary neutron star coalescence and stellar collapse with multipatch grids

2013 ◽  
Vol 87 (6) ◽  
Author(s):  
C. Reisswig ◽  
R. Haas ◽  
C. D. Ott ◽  
E. Abdikamalov ◽  
P. Mösta ◽  
...  
Keyword(s):  
Neutron Star ◽  
Three Dimensional ◽  
Relativistic Hydrodynamic ◽  
Hydrodynamic Simulations ◽  
Binary Neutron Star ◽  
Stellar Collapse ◽  
General Relativistic

scholarly journals 3D magnetized jet break-out from neutron-star binary merger ejecta: afterglow emission from the jet and the ejecta

2021 ◽  
Vol 502 (2) ◽  
pp. 1843-1855
Author(s):  
Antonios Nathanail ◽  
Ramandeep Gill ◽  
Oliver Porth ◽  
Christian M Fromm ◽  
Luciano Rezzolla
Keyword(s):  
Neutron Star ◽  
Thermal Emission ◽  
Opening Angle ◽  
Hollow Core ◽  
Binary Neutron Star ◽  
Vlbi Observations ◽  
Superluminal Motion ◽  
General Relativistic ◽  
Star Binary ◽  
Magnetohydrodynamic Simulations

ABSTRACT We perform 3D general-relativistic magnetohydrodynamic simulations to model the jet break-out from the ejecta expected to be produced in a binary neutron-star merger. The structure of the relativistic outflow from the 3D simulation confirms our previous results from 2D simulations, namely, that a relativistic magnetized outflow breaking out from the merger ejecta exhibits a hollow core of θcore ≈ 4°, an opening angle of θjet ≳ 10°, and is accompanied by a wind of ejected matter that will contribute to the kilonova emission. We also compute the non-thermal afterglow emission of the relativistic outflow and fit it to the panchromatic afterglow from GRB170817A, together with the superluminal motion reported from VLBI observations. In this way, we deduce an observer angle of $\theta _{\rm obs}= 35.7^{\circ \, \, +1.8}_{\phantom{\circ \, \, }-2.2}$. We further compute the afterglow emission from the ejected matter and constrain the parameter space for a scenario in which the matter responsible for the thermal kilonova emission will also lead to a non-thermal emission yet to be observed.

scholarly journals On the opening angle of magnetized jets from neutron-star mergers: the case of GRB170817A

2020 ◽  
Vol 495 (4) ◽  
pp. 3780-3787 ◽  
Author(s):  
Antonios Nathanail ◽  
Ramandeep Gill ◽  
Oliver Porth ◽  
Christian M Fromm ◽  
Luciano Rezzolla
Keyword(s):  
Neutron Star ◽  
Gamma Ray ◽  
Initial Conditions ◽  
Observation Angle ◽  
Opening Angle ◽  
Binary Neutron Star ◽  
Best Fitting ◽  
Standard Picture ◽  
General Relativistic ◽  
Star Binary

ABSTRACT The observations of GW170817/GRB170817A have confirmed that the coalescence of a neutron-star binary is the progenitor of a short gamma-ray burst (GRB). In the standard picture of a short GRB, a collimated highly relativistic outflow is launched after merger and it successfully breaks out from the surrounding ejected matter. Using initial conditions inspired from numerical-relativity binary neutron-star merger simulations, we have performed general-relativistic hydrodynamic (HD) and magnetohydrodynamic (MHD) simulations in which the jet is launched and propagates self-consistently. The complete set of simulations suggests that: (i) MHD jets have an intrinsic energy and velocity polar structure with a ‘hollow core’ subtending an angle θcore ≈ 4°–5° and an opening angle of θjet > ≳ 10°; (ii) MHD jets eject significant amounts of matter and two orders of magnitude more than HD jets; (iii) the energy stratification in MHD jets naturally yields the power-law energy scaling E(> Γβ) ∝ (Γβ)−4.5; (iv) MHD jets provide fits to the afterglow data from GRB170817A that are comparatively better than those of the HD jets and without free parameters; and (v) finally, both of the best-fitting HD/MHD models suggest an observation angle θobs ≃ 21° for GRB170817A.

scholarly journals General relativistic simulations of magnetized binary neutron star mergers

2008 ◽  
Vol 78 (2) ◽  
Author(s):  
Yuk Tung Liu ◽  
Stuart L. Shapiro ◽  
Zachariah B. Etienne ◽  
Keisuke Taniguchi
Keyword(s):  
Neutron Star ◽  
Binary Neutron Star ◽  
General Relativistic

scholarly journals General Relativistic Simulations of Binary Neutron Star Mergers

2011 ◽  
Author(s):  
Bruno Giacomazzo ◽  
Luciano Rezzolla ◽  
Luca Baiotti ◽  
David Link ◽  
José A. Font ◽  
...  
Keyword(s):  
Neutron Star ◽  
Binary Neutron Star ◽  
General Relativistic

scholarly journals Multimessenger Predictions from 3D General-Relativistic Core-Collapse Supernovae Models

2017 ◽  
Vol 12 (S331) ◽  
pp. 329-338
Author(s):  
Kei Kotake ◽  
Takami Kuroda ◽  
Kazuhiro Hayama
Keyword(s):  
Neutron Star ◽  
Equations Of State ◽  
Three Dimensional ◽  
Time Correlation ◽  
Sensitivity Range ◽  
General Relativistic ◽  
Live Broadcast ◽  
Accretion Shock ◽  
Star Surface ◽  
Proto Neutron Star

AbstractIn this contribution, we present results from fully general-relativistic three-dimensional (3D) simulations of a non-rotating 15M⊙ star using different nuclear equations of state (EOSs). We show that the SASI (standing-accretion-shock-instability) activity occurs much more vigorously in models with softer EOS. By performing detailed analysis of the gravitational-wave (GW) emission, we find a new GW signature that is produced predominantly by the SASI-induced downflows to the proto-neutron star. We discuss the detectability of the GW signal by performing a coherent network analysis where multiple detectors including LIGO Hanford, LIGO Livingston, VIRGO, and KAGRA are considered. We point out that the GW signal, whose typical frequency is in the best sensitivity range of the laser-interferometers, could potentially provide the live broadcast that pictures how the supernova shock is dancing in the core. The detection horizon of the signal is estimated as 2~3 kpc for the current generation detectors, which can extend up to ~100 kpc for the third generation detectors like Cosmic Explorer. We furthermore perform a correlation analysis between the SASI-modulated GW and neutrino signals. Our results show that the time correlation of the two signals becomes highest when we take into account the travel timescale of adverting material from the (average) neutrino-sphere to the proto-neutron star surface.

scholarly journals Neutron star merger remnants

2020 ◽  
Vol 52 (11) ◽  
Author(s):  
Sebastiano Bernuzzi
Keyword(s):  
Neutron Star ◽  
Nuclear Matter ◽  
Gravitational Wave ◽  
Weak Interactions ◽  
Numerical Relativity ◽  
Current Understanding ◽  
Fundamental Physics ◽  
Binary Neutron Star ◽  
General Relativistic ◽  
Relativistic Models

AbstractBinary neutron star mergers observations are a unique way to constrain fundamental physics and astrophysics at the extreme. The interpretation of gravitational-wave events and their electromagnetic counterparts crucially relies on general-relativistic models of the merger remnants. Quantitative models can be obtained only by means of numerical relativity simulations in $$3+1$$ 3 + 1 dimensions including detailed input physics for the nuclear matter, electromagnetic and weak interactions. This review summarizes the current understanding of merger remnants focusing on some of the aspects that are relevant for multimessenger observations.

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