General relativistic MHD simulations of non-thermal flaring in Sagittarius A*

Abstract

Sagittarius A* exhibits regular variability in its multiwavelength emission, including daily X-ray flares and roughly continuous near-infrared (NIR) flickering. The origin of this variability is still ambiguous since both inverse Compton and synchrotron emission are possible radiative mechanisms. The underlying particle distributions are also not well constrained, particularly the non-thermal contribution. In this work, we employ the GPU-accelerated general relativistic magnetohydrodynamics (GRMHD) code H-AMR perform a study of flare flux distributions, including the effect of particle acceleration for the first time in high-resolution 3D simulations of Sgr A*. For the particle acceleration, we use the general relativistic ray-tracing (GRRT) code BHOSS to perform the radiative transfer, assuming a hybrid thermal+non-thermal electron energy distribution. We extract ~60 h lightcurves in the sub-millimetre, NIR and X-ray wavebands, and compare the power spectra and the cumulative flux distributions of the lightcurves to statistical descriptions for Sgr A* flares. Our results indicate that non-thermal populations of electrons arising from turbulence-driven reconnection in weakly magnetised accretion flows lead to moderate NIR and X-ray flares and reasonably describe the X-ray flux distribution while fulfilling multiwavelength flux constraints. These models exhibit high rms% amplitudes, >~150% both in the NIR and the X-rays, with changes in the accretion rate driving the 230~GHz flux variability, in agreement with Sgr A* observations.

Accepted by MNRAS

References in corpus (30)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
• Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre
• Trigonometric Parallaxes Of High-Mass Star Forming Regions: Our View Of The Milky Way
• An Update on Monitoring Stellar Orbits in the Galactic Center
• Formation of Hard Power-laws in the Energetic Particle Spectra Resulting from Relativistic Magnetic Reconnection
• A new method for shadow calculations: application to parameterised axisymmetric black holes
• Relativistic Jets Shine through Shocks or Magnetic Reconnection?
• An Unambiguous Detection of Faraday Rotation in Sagittarius A*
• An Improved Distance and Mass Estimate for Sgr A* from a Multistar Orbit Analysis
• The Submillimeter Bump in Sgr A* from Relativistic MHD Simulations
• A Constant Spectral Index for Sagittarius A* During Infrared/X-ray Intensity Variations
• The Disc-Jet Symbiosis Emerges: Modeling the Emission of Sagittarius A* with Electron Thermodynamics
• Radio and Millimeter Monitoring of Sgr A*: Spectrum, Variability, and Constraints on the G2 Encounter
• Electron and proton heating in trans-relativistic magnetic reconnection
• The Size, Shape, and Scattering of Sagittarius A* at 86 GHz: First VLBI with ALMA
• Ab Initio Horizon-Scale Simulations of Magnetically Arrested Accretion in Sagittarius A* Fed by Stellar Winds
• Sgr A* near-infrared flares from reconnection events in a magnetically arrested disc
• How to hide large scale outflows: size constraints on the jets of Sgr A*
• Time Dependent Models of Flares from Sagittarius A*
• NuSTAR detection of high-energy X-ray emission and rapid variability from Sagittarius A* flares
• The Radiative Efficiency and Spectra of Slowly Accreting Black Holes from Two-Temperature GRRMHD Simulations
• ALMA and VLA measurements of frequency-dependent time lags in Sagittarius A*: evidence for a relativistic outflow
• Comparison of the ion-to-electron temperature ratio prescription: GRMHD simulations with electron thermodynamics
• The X-ray Flux Distribution of Sagittarius A* as Seen by Chandra
• The Flux Distribution of Sgr A*
• Spectral and Imaging properties of Sgr A* from High-Resolution 3D GRMHD Simulations with Radiative Cooling
• Exploring plasma evolution during Sagittarius A* flares
• On the Comparison of AGN with GRMHD Simulations: I. Sgr A*
• Sagittarius A* High Energy X-ray Flare Properties During NuSTAR Monitoring of the Galactic Center from 2012 to 2015

Cited by in corpus (32)

• First Sagittarius A* Event Horizon Telescope Results. VI: Testing the Black Hole Metric
• First Sagittarius A* Event Horizon Telescope Results. V. Testing Astrophysical Models of the Galactic Center Black Hole
• Black hole flares: ejection of accreted magnetic flux through 3D plasmoid-mediated reconnection
• Jets in Magnetically Arrested Hot Accretion Flows: Geometry, Power and Black Hole Spindown
• Millimeter light curves of Sagittarius A* observed during the 2017 Event Horizon Telescope campaign
• Flux eruption events drive angular momentum transport in magnetically arrested accretion flows
• Sgr A* X-ray flares from non-thermal particle acceleration in a magnetically arrested disc
• Constraining particle acceleration in Sgr A* with simultaneous GRAVITY, Spitzer, NuSTAR and Chandra observations
• Modeling the inner part of the jet in M87: Confronting jet morphology with theory
• Spinning black holes magnetically connected to a Keplerian disk -- Magnetosphere, reconnection sheet, particle acceleration and coronal heating
• Observational Signatures of Frame Dragging in Strong Gravity
• Microphysical Plasma Relations from Special-relativistic Turbulence
• Life cycle of cosmic-ray electrons in the intracluster medium
• A "coronal-mass-ejection'' model for flares in Sagittarius A*
• Accretion Flow Morphology in Numerical Simulations of Black Holes from the ngEHT Model Library: The Impact of Radiation Physics
• Flares and their echoes can help distinguish photon rings from black holes with space-Earth very long baseline interferometry
• General relativistic effects and the near-infrared and X-ray variability of Sgr A* I
• Multi-wavelength Variability of Sagittarius A* in July 2019
• Toward General-Relativistic Magnetohydrodynamics Simulations in Stationary Non-Vacuum Spacetimes
• The Super-Alfvénic Rotational Instability in accretion disks about black holes
• Misaligned magnetized accretion flows onto spinning black holes: Magneto-spin alignment, outflow power, and intermittent jets
• RAIKOU: A General Relativistic, Multi-wavelength Radiative Transfer Code
• Parameter study for hot spot trajectories around Sgr$A\ast$
• Truncated accretion discs in black hole X-ray binaries: dynamics and variability signatures
• Magnetically arrested disk flux eruption events to describe SgrA* flares
• A Swift study of long-term changes in the X-ray flaring properties of Sagittarius A*
• Forward Ray Tracing and Hot Spots in Kerr Spacetime
• The impact of resistivity on the variability of black hole accretion flows
• Deep learning inference with the Event Horizon Telescope II. The Zingularity framework for Bayesian artificial neural networks
• New Evidence for a Flux-independent Spectral Index of Sgr A* in the Near-infrared
• Impact of the nonthermal electron radiation effects on the horizon scale image structure of Sagittarius A*
• Extreme magnetic fields around black holes