New conservation laws in general-relativistic magnetohydrodynamics

1978 ◽  
Vol 18 (6) ◽  
pp. 1809-1819 ◽  
Author(s):  
Jacob D. Bekenstein ◽  
Eliezer Oron
Keyword(s):  
Conservation Laws ◽  
General Relativistic ◽  
Relativistic Magnetohydrodynamics

ON MAGNETIC SELF-COLLIMATION OF RELATIVISTIC JETS

2010 ◽  
Vol 19 (06) ◽  
pp. 689-694
Author(s):  
N. GLOBUS ◽  
V. CAYATTE ◽  
C. SAUTY
Keyword(s):  
Black Hole ◽  
Total Energy ◽  
Ideal Fluid ◽  
Polar Axis ◽  
Kerr Metric ◽  
Relativistic Jets ◽  
Simple Criterion ◽  
General Relativistic ◽  
Time Splitting ◽  
Relativistic Magnetohydrodynamics

We present a semi-analytical model using the equations of general relativistic magnetohydrodynamics (GRMHD) for jets emitted by a rotating black hole. We assume steady axisymmetric outflows of a relativistic ideal fluid in Kerr metrics. We express the conservation equations in the frame of the FIDucial Observer (FIDO or ZAMO) using a 3+1 space–time splitting. Calculating the total energy variation between a non-polar field line and the polar axis, we extend to the Kerr metric the simple criterion for the magnetic collimation of jets obtained for a nonrotating black hole by Meliani et al.10 We show that the black role rotation induced a more efficient magnetic collimation of the jet.

scholarly journals iharm3D: Vectorized General Relativistic Magnetohydrodynamics

2021 ◽  
Vol 6 (66) ◽  
pp. 3336
Author(s):  
Ben Prather ◽  
George Wong ◽  
Vedant Dhruv ◽  
Benjamin Ryan ◽  
Joshua Dolence ◽  
...  
Keyword(s):  
General Relativistic ◽  
Relativistic Magnetohydrodynamics

scholarly journals Observational signatures of disc and jet misalignment in images of accreting black holes

2020 ◽  
Vol 499 (1) ◽  
pp. 362-378
Author(s):  
K Chatterjee ◽  
Z Younsi ◽  
M Liska ◽  
A Tchekhovskoy ◽  
S B Markoff ◽  
...  
Keyword(s):  
Accretion Disc ◽  
Accretion Discs ◽  
Time Variability ◽  
Noticeable Effect ◽  
Efficient Energy ◽  
Rotation Axes ◽  
General Relativistic ◽  
Extraction Processes ◽  
Relativistic Magnetohydrodynamics ◽  
Tilted Disc

ABSTRACT Black hole (BH) accretion is one of nature’s most efficient energy extraction processes. When gas falls in, a significant fraction of its gravitational binding energy is either converted into radiation or flows outwards in the form of BH-driven jets and disc-driven winds. Recently, the Event Horizon Telescope (EHT), an Earth-sized submillimetre radio interferometer, captured the first images of M87’s BH. These images were analysed and interpreted using general relativistic magnetohydrodynamics (GRMHD) models of accretion discs with rotation axes aligned with the BH spin axis. However, since infalling gas is often insensitive to the BH spin direction, misalignment between accretion disc and BH spin may be a common occurrence in nature. In this work, we use the general relativistic radiative transfer code bhoss to calculate the first synthetic radio images of (highly) tilted disc/jet models generated by our GPU-accelerated GRMHD code h-amr . While the tilt does not have a noticeable effect on the system dynamics beyond a few tens of gravitational radii from the BH, the warping of the disc and jet can imprint observable signatures in EHT images on smaller scales. Comparing the images from our GRMHD models to the 43 and 230 GHz EHT images of M87, we find that M87 may feature a tilted disc/jet system. Further, tilted discs and jets display significant time variability in the 230 GHz flux that can be further tested by longer-duration EHT observations of M87.

scholarly journals Barycentric interpolation on Riemannian and semi-Riemannian spaces

2019 ◽  
Vol 489 (3) ◽  
pp. 4161-4169
Author(s):  
Pauli Pihajoki ◽  
Matias Mannerkoski ◽  
Peter H Johansson
Keyword(s):  
Interpolation Method ◽  
Arbitrary Dimension ◽  
Curvilinear Coordinates ◽  
Barycentric Coordinates ◽  
Intrinsic Variability ◽  
Curvature Effects ◽  
Barycentric Interpolation ◽  
General Relativistic ◽  
Relativistic Magnetohydrodynamics ◽  
Riemannian Spaces

ABSTRACT Interpolation of data represented in curvilinear coordinates and possibly having some non-trivial, typically Riemannian or semi-Riemannian geometry is a ubiquitous task in all of physics. In this work, we present a covariant generalization of the barycentric coordinates and the barycentric interpolation method for Riemannian and semi-Riemannian spaces of arbitrary dimension. We show that our new method preserves the linear accuracy property of barycentric interpolation in a coordinate-invariant sense. In addition, we show how the method can be used to interpolate constrained quantities so that the given constraint is automatically respected. We showcase the method with two astrophysics related examples situated in the curved Kerr space–time. The first problem is interpolating a locally constant vector field, in which case curvature effects are expected to be maximally important. The second example is a general relativistic magnetohydrodynamics simulation of a turbulent accretion flow around a black hole, wherein high intrinsic variability is expected to be at least as important as curvature effects.

scholarly journals GRHydro: a new open-source general-relativistic magnetohydrodynamics code for the Einstein toolkit

2013 ◽  
Vol 31 (1) ◽  
pp. 015005 ◽  
Author(s):  
Philipp Mösta ◽  
Bruno C Mundim ◽  
Joshua A Faber ◽  
Roland Haas ◽  
Scott C Noble ◽  
...  
Keyword(s):  
Open Source ◽  
General Relativistic ◽  
Relativistic Magnetohydrodynamics

scholarly journals Linear and circular polarization of a 1D relativistic jet model

2019 ◽  
Vol 623 ◽  
pp. A152 ◽  
Author(s):  
M. Mościbrodzka
Keyword(s):  
Black Hole ◽  
Three Dimensional ◽  
Compact Objects ◽  
Slab Geometry ◽  
Relativistic Jet ◽  
General Relativistic ◽  
Low Dimensional ◽  
Polarization Models ◽  
Radiative Transfer Equations ◽  
Relativistic Magnetohydrodynamics

Context. Polarimetric observations of black holes allow us to probe structures of magnetic fields and plasmas in strong gravity. Aims. We present a study of the polarimetric properties of a synchrotron spectrum emitted from a relativistic jet using a low-dimensional model. Methods. A novel numerical scheme is used to integrate relativistic polarized radiative transfer equations in a slab geometry where the plasma conditions change along the integration path. Results. We find that the simple model of a non-uniform jet can recover basic observational characteristics of some astrophysical sources with a relativistic jet, such as extremely high rotation measures. Our models incorporate a time-dependent component. A small fluctuation in density or temperature of the plasma along the jet produces significant amounts of fluctuations not only in the fractional linear and circular polarizations, but also in the jet internal rotation measures. Conclusions. The low-dimensional models presented here are developed within the same computational framework as the complex three-dimensional general relativistic magnetohydrodynamics simulations of black hole disks and jets, and they offer guidance when interpreting the results from more complex polarization models. The models presented here are scalable to stationary and transient polarized radio emissions produced by relativistic plasma ejected from around compact objects, in both stellar-mass and supermassive black hole systems.

scholarly journals Wave properties of plasma surrounding the event horizon of a nonrotating black hole

2008 ◽  
Vol 86 (11) ◽  
pp. 1265-1285 ◽  
Author(s):  
M Sharif ◽  
G Mustafa
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Schwarzschild Black Hole ◽  
Magnetohydrodynamics Equations ◽  
Normal Dispersion ◽  
Isothermal Plasma ◽  
General Relativistic ◽  
Relativistic Magnetohydrodynamics ◽  
Wave Properties ◽  
Complex Dispersion

We study the wave properties of a cold isothermal plasma in the vicinity of a Schwarzschild black-hole event horizon. The Fourier-analyzed perturbed 3+1 general relativistic magnetohydrodynamics equations are examined such that the complex dispersion relations are obtained for nonrotating, rotating nonmagnetized, and rotating magnetized backgrounds. The propagation and attenuation vectors along with the refractive index are obtained (shown graphically) to study the dispersive properties of the medium near the event horizon. The results show that no information can be obtained from the Schwarzschild magnetosphere. Further, the pressure stops the existence of normal dispersion of waves.PACS Nos.: 95.30.Sf, 95.30.Qd, 04.30.Nk

scholarly journals Numerical 3+1 General Relativistic Magnetohydrodynamics: A Local Characteristic Approach

2006 ◽  
Vol 637 (1) ◽  
pp. 296-312 ◽  
Author(s):  
Luis Anton ◽  
Olindo Zanotti ◽  
Juan A. Miralles ◽  
Jose M. Marti ◽  
Jose M. Ibanez ◽  
...  
Keyword(s):  
Local Characteristic ◽  
General Relativistic ◽  
Relativistic Magnetohydrodynamics
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