Abstract Magnetic reconnection can power bright, rapid flares originating from the inner magnetosphere of accreting black holes. We conduct extremely high-resolution (5376 × 2304 cells) general-relativistic magnetohydrodynamics simulations, capturing plasmoid-mediated in a 3D magnetically arrested disk for first time. show that an equatorial, plasmoid-unstable current sheet forms transient, nonaxisymmetric, low-density within few Schwarzschild radii. flux bundles escape event horizon through...

Abstract The Event Horizon Telescope Collaboration (EHTC) observed the Galactic centre source Sagittarius A* (Sgr A*) and used emission models primarily based on single ion temperature (1T) general relativistic magnetohydrodynamic (GRMHD) simulations. This predicted is strongly dependent a modelled prescription of ion-to-electron ratio. most promising are magnetically arrested disk (MAD) states. However, nearly all MAD exhibit larger temporal fluctuations in radiative 230 GHz compared to...

General-relativistic magnetohydrodynamic (GRMHD) simulations have revolutionized our understanding of black hole accretion. Here, we present a graphics processing unit (GPU) accelerated GRMHD code \hammer{} with multi-faceted optimizations that, collectively, accelerate computation by 2-5 orders magnitude for wide range applications. Firstly, it introduces spherical grid 3D adaptive mesh refinement that operates in each the 3 dimensions independently. This allows us to circumvent Courant...

Abstract In many black hole (BH) systems, the accretion disk is expected to be misaligned with respect BH spin axis. If scale height of much smaller than misalignment angle, can tear into multiple, independently precessing “sub-disks.” This most likely happen during outbursts in X-Ray binaries (BHXRBs) and active galactic nuclei (AGNs) accreting above a few percent Eddington limit, because becomes razor-thin. Disk tearing has potential explain variability phenomena including quasi-periodic...

Abstract The angular momentum of gas feeding a black hole (BH) may be misaligned with respect to the BH spin, resulting in tilted accretion disk. Rotation drags surrounding spacetime, manifesting as Lense–Thirring torques that lead disk precession and warping. We study these processes by simulating thin ( H / r = 0.02), highly <?CDATA ${ \mathcal T }=65^\circ $?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi mathvariant="italic"></mml:mi>...

Abstract The conventional accretion disk lore is that magnetized turbulence the principal angular momentum transport process drives accretion. However, when dynamically important large-scale magnetic fields thread an disk, they can produce mass and outflows, known as winds , also drive Yet, relative importance of turbulent wind-driven still poorly understood. To probe this question, we analyze a long-duration (1.2 × 10 5 r g / c ) simulation rapidly rotating ( = 0.9) black hole feeding from...

Abstract Black hole (Bh) X-ray binaries cycle through different spectral states of accretion over the course months to years. Although persistent changes in Bh mass rate are generally recognized as most important component state transitions, it is becoming increasingly evident that magnetic fields play a similarly role. In this article, we present first radiative two-temperature general relativistic magnetohydrodynamics simulations which an disk transitions from quiescent at <mml:math...

ABSTRACT Polarization measurements by the Event Horizon Telescope from M87* and Sgr A* suggest that there is a dynamically strong, ordered magnetic field, typical of what expected magnetically arrested accretion disc (MAD). In such discs, strong poloidal field can suppress flow cause episodic flux eruptions. Recent work shows general relativistic magnetohydrodynamic (GRMHD) MAD simulations feature dynamics turbulence mixing instabilities are becoming resolved at higher resolutions. We...

The occurrence of dual active galactic nuclei (AGN) on scales a few tens kpc can be used to study merger-induced accretion massive black holes (MBHs) and derive clues MBH mergers, using AGN as parent population precursors. We investigate the properties in cosmological simulation Horizon-AGN. create catalogs selected with distance luminosity criteria, plus sub-catalogs where further mass cuts are applied. divide sample into hosted different galaxies, way merger, those one galaxy, after galaxy...

ABSTRACT Black hole X-ray binaries (BHXRBs) display a wide range of variability phenomena, from long duration spectral state changes to short-term broad-band and quasi-periodic oscillations (QPOs). A particularly puzzling aspect is the production QPOs, which – if properly understood could be used as powerful diagnostic tool black accretion evolution. In this work, we analyse high-resolution 3D general relativistic magnetohydrodynamic simulation geometrically thin disc, tilted by 65° with...

The occurrence of dual active galactic nuclei (AGN) on scales a few tens kpc can be used to study merger-induced accretion massive black holes (MBHs) and derive clues MBH mergers, using AGN as parent population precursors. We investigate the properties in cosmological simulation Horizon-AGN. create catalogs selected with distance luminosity criteria, plus sub-catalogs where further mass cuts are applied. divide sample into hosted different galaxies, way merger, those one galaxy, after galaxy...

Black hole (BH) X-ray binaries cycle through different spectral states of accretion over the course months to years. Although fluctuations in BH mass rate are generally recognized as most important component state transitions, it is becoming increasingly evident that magnetic fields play a similarly role. In this article, we present first radiative two-temperature (2T) general relativistic magnetohydrodynamics (GRMHD) simulations which an disk transitions from quiescent at $\dot{M} \sim...

Radio observations suggest that 3C 75, located in the dumbbell shaped galaxy NGC 1128 at center of Abell 400, hosts two colliding jets. Motivated by this source, we perform three-dimensional hydrodynamical simulations using a modified version GPU-accelerated Adaptive-MEsh-Refinement parallel code ($\mathit{GAMER}$) to study extragalactic We find jets can be cast into categories: 1) bouncing jets, which case bounce off each other keeping their identities, and 2) merging when only one jet...

Polarisation measurements by the Event Horizon Telescope from M87$^{\ast}$ and Sgr A$^\ast$ suggest that there is a dynamically strong, ordered magnetic field, typical of what expected magnetically arrested accretion disk (MAD). In such disks strong poloidal field can suppress flow cause episodic flux eruptions. Recent work shows General Relativistic Magnetohydrodynamic (GRMHD) MAD simulations feature dynamics turbulence mixing instabilities are becoming resolved at higher resolutions. We...

The Event Horizon Telescope Collaboration (EHTC) observed the Galactic centre source Sgr A* and used emission models primarily based on single ion temperature (1T) general relativistic magnetohydrodynamic (GRMHD) simulations. This predicted is strongly dependent a modelled prescription of ion-to-electron ratio. two most promising are magnetically arrested disk (MAD) states. However, these nearly all MAD exhibit greater light-curve variability at 230 GHz compared to historical observations....

ABSTRACT The radio galaxy 3C 75 is remarkable because it contains a pair of radio-loud active galaxies, each which produces two-sided jet, with the jet beams appearing to collide and merge west galaxies. Motivated by 75, we have conducted three-dimensional hydrodynamic simulations collisions. We extended previous studies modelling physical properties cluster atmosphere, including an external wind, using realistic powers obtained from observational data. are able produce morphology similar...

ABSTRACT Numerical simulations play an essential role in helping us to understand the physical processes behind relativistic jets active galactic nuclei. The large number of hydrodynamic codes available today enables a variety different numerical algorithms be utilized when conducting simulations. Since many presented literature use combinations it is important quantify differences jet evolution that can arise due precise schemes used. We conduct series using flash (magneto-)hydrodynamics...

The conventional accretion disk lore is that magnetized turbulence the principal angular momentum transport process drives accretion. However, when dynamically important large-scale magnetic fields thread an disk, they can produce mass and outflows, known as winds, also drive Yet, relative importance of turbulent wind-driven still poorly understood. To probe this question, we analyze a long-duration ($1.2 \times 10^5 r_{\rm g}/c$) simulation rapidly rotating ($a=0.9$) black hole feeding from...

The angular momentum of gas feeding a black hole (BH) is typically misaligned with respect to the BH spin, resulting in tilted accretion disk. Rotation drags surrounding space-time, manifesting as Lense-Thirring torques that lead disk precession and warping. We study these processes by simulating thin ($H/r=0.02$), highly ($\mathcal{T}=65^\circ$) around rapidly rotating ($a=0.9375$) at extremely high resolutions, which we performed using general-relativistic magnetohydrodynamic (GRMHD) code...