Jet launching of M87

Bandyopadhyay, Bidisha

doi:10.1038/s41550-021-01535-5

“…It is a black hole whose shadow was directly imaged by the Event Horizon Telescope (EHT) [1][2][3][4], with a mass of approximately 6.5 × 10 9 M ⊙ . Following the first direct observation, numerous scientists have embarked on studies to further understand the mass, spin parameters, and QPO frequencies of M87* [56,57]. Additionally, various attempts have been made to elucidate the physical properties of these black holes and their QPO frequencies using alternative theories of gravity.…”

Section: Possible Qpo Models and Observed Frequencies From Numerical ...mentioning

confidence: 99%

Bondi–Hoyle accretion around the non-rotating black hole in 4D Einstein–Gauss–Bonnet gravity

Dönmez

¹

2021

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In this paper, the numerical investigation of a Bondi–Hoyle accretion around a non-rotating black hole in a novel four dimensional Einstein–Gauss–Bonnet gravity is investigated by solving the general relativistic hydrodynamical equations using the high resolution shock capturing scheme. For this purpose, the accreated matter from the wind-accreating X-ray binaries falls towards the black hole from the far upstream side of the domain, supersonically. We study the effects of Gauss–Bonnet coupling constant $$\alpha $$ α in 4D EGB gravity on the accreated matter and shock cones created in the downstream region in detail. The required time having the shock cone in downstream region is getting smaller for $$\alpha > 0$$ α > 0 while it is increasing for $$\alpha < 0$$ α < 0 . It is found that increases in $$\alpha $$ α leads violent oscillations inside the shock cone and increases the accretion efficiency. The violent oscillations would cause increase in the energy flux, temperature, and spectrum of X-rays. So the quasi-periodic oscillations (QPOs) are naturally produced inside the shock cone when $$-5 \le \alpha \le 0.8$$ - 5 ≤ α ≤ 0.8 . It is also confirmed that EGB black hole solution converges to the Schwarzschild one in general relativity when $$\alpha \rightarrow 0$$ α → 0 . Besides, the negative coupling constants also give reasonable physical solutions and increase of $$\alpha $$ α in negative directions suppresses the possible oscillation observed in the shock cone.

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“…Clearly, it is essential to connect the microphysical properties of the plasma with the macrophysical ones β and σ, where hybrid-kinetic models might have some limitations (Valentini et al 2014;Cerri et al 2017;Arzamasskiy et al 2019). To this scope, we have performed 38 large-scale fully kinetic (i.e., both protons and electrons are treated as particles) particle-in-cell (PIC) simulations of special-relativistic plasma in the so-called "transrelativistic regime," that is, when the plasma magnetization σ-the ratio between the magnetic energy density to enthaply density (see below for a definition)-is of order unity (Ripperda et al 2019;Janssen et al 2021;Mizuno et al 2021;Bandyopadhyay 2022), and covering 4 orders of magnitude in the plasma-β parameter (see the Appendix for details on the various simulations). In all simulations, we employ a physical proton-to-electron mass ratio (see Rowan et al 2017, for the importance of using a realistic mass ratio), and analyze the most important microphysical properties of the turbulent plasma, namely, the spectral index of the electron energy distributions κ, the efficiency in the production of nonthermal particles  , and the temperature ratio =  T T : e p .…”

Section: Introductionmentioning

confidence: 99%

Microphysical Plasma Relations from Special-relativistic Turbulence

Meringolo

¹

,

Cruz-Osorio

²

,

Rezzolla

³

et al. 2023

ApJ

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The microphysical, kinetic properties of astrophysical plasmas near accreting compact objects are still poorly understood. For instance, in modern general-relativistic magnetohydrodynamic simulations, the relation between the temperature of electrons T e and protons T p is prescribed in terms of simplified phenomenological models where the electron temperature is related to the proton temperature in terms of the ratio between the gas and magnetic pressures, or the β parameter. We here present a very comprehensive campaign of two-dimensional kinetic particle-in-cell simulations of special-relativistic turbulence to investigate systematically the microphysical properties of the plasma in the transrelativistic regime. Using a realistic mass ratio between electrons and protons, we analyze how the index of the electron energy distributions κ, the efficiency of nonthermal particle production  , and the temperature ratio  := T e / T p vary over a wide range of values of β and σ. For each of these quantities, we provide two-dimensional fitting functions that describe their behavior in the relevant space of parameters, thus connecting the microphysical properties of the plasma, κ,  , and  , with the macrophysical ones β and σ. In this way, our results can find application in a wide range of astrophysical scenarios, including the accretion and the jet emission onto supermassive black holes, such as M87* and Sgr A*.

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“…Clearly, it is essential to connect the microphysical properties of the plasma with the macrophysical ones β and σ, where hybrid-kinetic models might have some limitations (Arzamasskiy et al 2019;Valentini et al 2014;Cerri et al 2017). To this scope, we have performed 38 large-scale fully kinetic (i.e., both protons and electrons are treated as particles) Particle-In-Cell (PIC) simulations of special-relativistic plasma in the so-called "trans-relativistic regime", that is, when the plasma magnetization σ -the ratio between the magnetic energy density to enthaply density (see below for a definition) -is of order unity (Ripperda et al 2019;Mizuno et al 2021;Bandyopadhyay 2022;Janssen et al 2021), and covering four orders of magnitude in the plasma-β parameter (see Appendix for details on the various simulations). In all simulations, we employ a physical proton-to-electron mass ratio (see Rowan et al 2017, for the importance of using a realistic mass ratio), and analyze the most important microphysical properties of the turbulent plasma, namely, the spectral index of the electron energy distributions κ, the efficiency in the production of nonthermal particles E, and the temperature ratio T := T e /T p .…”

Section: Introductionmentioning

confidence: 99%

Microphysical plasma relations from kinetic modelling of special-relativistic turbulence

Meringolo¹,

Cruz-Osorio²,

Rezzolla³

et al. 2023

Preprint

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The microphysical, kinetic properties of astrophysical plasmas near accreting compact objects are still poorly understood. For instance, in modern general-relativistic magnetohydrodynamic simulations, the relation between the temperature of electrons T e and protons T p is prescribed in terms of simplified phenomenological models where the electron temperature is related to the proton temperature in terms of the ratio between the gas and magnetic pressures, or β parameter. We here present a very comprehensive campaign of two-dimensional kinetic Particle-In-Cell (PIC) simulations of special-relativistic turbulence to investigate systematically the microphysical properties of the plasma in the trans-relativistic regime. Using a realistic mass ratio between electrons and protons, we analyze how the index of the electron energy distributions κ, the efficiency of nonthermal particle production E, and the temperature ratio T := T e /T p , vary over a wide range of values of β and σ. For each of these quantities, we provide two-dimensional fitting functions that describe their behaviour in the relevant space of parameters, thus connecting the microphysical properties of the plasma, κ, E, and T , with the macrophysical ones β and σ. In this way, our results can find application in wide range of astrophysical scenarios, including the accretion and the jet emission onto supermassive black holes, such as M87* and Sgr A*.

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Jet launching of M87

Cited by 4 publications

References 9 publications

Bondi–Hoyle accretion around the non-rotating black hole in 4D Einstein–Gauss–Bonnet gravity

Bondi–Hoyle accretion around the non-rotating black hole in 4D Einstein–Gauss–Bonnet gravity

Microphysical Plasma Relations from Special-relativistic Turbulence

Microphysical plasma relations from kinetic modelling of special-relativistic turbulence

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