Two-dimensional inflow-wind solution of black hole accretion with an evenly symmetric magnetic field

Mosallanezhad, Amin; Bu, De-Fu; Yuan, Feng

doi:10.1093/mnras/stv2881

Cited by 27 publications

(26 citation statements)

References 41 publications

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“…We used simple onedimensional self-similar solutions for the density and magnetic field strength in the hot accretion flows model, while it is unclear whether this is valid or not. Studies of two dimensional solutions of hot accretion flows showed a breakdown of spherical symmetry (e.g., Mosallanezhad et al 2016;Bu & Mosallanezhad 2018), though the behavior of physical parameters measured close to the jet axis is poorly constrained yet. We assumed ≈ 130 rad/m 2 for the contribution of the diffuse gas in M87 outside the Bondi radius based on the results of RM studies of the large scale jet but this could be uncertain.…”

Section: Discussionmentioning

confidence: 99%

Faraday Rotation in the Jet of M87 inside the Bondi Radius: Indication of Winds from Hot Accretion Flows Confining the Relativistic Jet

Park

Hada

Kino

et al. 2019

ApJ

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We study Faraday rotation in the jet of M87 inside the Bondi radius using eight Very Long Baseline Array data sets, one at 8 GHz, four at 5 GHz, and three at 2 GHz. We obtain Faraday rotation measures (RMs) measured across the bandwidth of each data set. We find that the magnitude of RM systematically decreases with increasing distance from the black hole from 5,000 to 200,000 Schwarzschild radii. The data, showing predominantly negative RM sign without significant difference of the RMs on the northern and southern jet edges, suggest that the spatial extent of the Faraday screen is much larger than the jet. We apply models of hot accretion flows, thought to be prevalent in active galactic nuclei having relatively low luminosity such as M87, and find that the decrease of RM is described well by a gas density profile ρ ∝ r −1 . This behavior matches the theoretically expected signature of substantial winds, nonrelativistic un-collimated gas outflows from hot accretion flows, which is consistent with the results of various numerical simulations. The pressure profile inferred from the density profile is flat enough to collimate the jet, which can result in gradual acceleration of the jet in a magneto-hydrodynamical process. This picture is in good agreement with the observed gradual collimation and acceleration of the M87 jet inside the Bondi radius. The dominance of negative RMs suggests that jet and wind axis are misaligned such that the jet emission exposes only one side of the toroidal magnetic fields permeating the winds.

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Section: Discussionmentioning

confidence: 99%

Faraday Rotation in the Jet of M87 inside the Bondi Radius: Indication of Winds from Hot Accretion Flows Confining the Relativistic Jet

Park

Hada

Kino

et al. 2019

ApJ

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“…The relevant study starts from the pioneer hydrodynamical simulation work by Stone et al (1999) and followed by both analytical works and hydrodynamical and magneto-hydrodynamical numerical simulations (e.g., Yuan et al 2012a,b;Narayan et al 2012;Li et al 2013;Sadowski et al 2013;Yuan et al 2015;Bu et al 2016a,b;Mosallanezhad et al 2016). Different from the wind from cold mode, theoretical study of wind from hot mode is much easier.…”

Section: Physics Of the Cold And Hot Accretion Modesmentioning

confidence: 99%

On the Role of the Hot Feedback Mode in Active Galactic Nuclei Feedback in an Elliptical Galaxy

Yoon

Yuan

Ostriker

et al. 2019

ApJ

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Depending on the value of the accretion rate, black hole accretion is divided into cold and hot modes. The two modes have distinctly different physics and correspond to two feedback modes. Most previous feedback works either focus only on one mode, or the accretion physics is not always properly adopted. Here, by performing hydrodynamical numerical simulations of AGN feedback in an elliptical galaxy, we show that including both is important, and gives different results from including just one or the other. We specifically focus on the wind and radiation (but neglecting the jet) feedback in the hot mode, to explore whether this particular mode of feedback can play any important feedback role. For this aim, we have run two test models. In one model, we always adopt the cold mode no matter what value the accretion rate is; in another model, we turn off the AGN once it enters into the hot mode. We have calculated the AGN light curves, black hole growth, star formation, and AGN energy duty-cycle; and compared the results with the model in which the two modes are correctly included. Important differences are found. For example, if we were to adopt only the cold mode, the total mass of newly formed stars would become two orders of magnitude smaller, and the fraction of energy ejected within the high accretion regime (i.e., L BH > 2%L Edd ) would be too small to be consistent with observations. We have also investigated the respective roles of wind and radiation in the hot mode.

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“…Despite the even symmetry case has become fashionable, the odd symmetry structure that we have studied may be more realistic in the case that the field is due to dynamo processes since in the disc the fastest growing dynamo field mode has odd symmetry (Brandenburg & von Rekowski 2007). In this work we are aiming to study an odd z-symmetric structure for B-field as below (the same problem with even symmetric configuration has been solved recently by Mosallanezhad, Bu, Yuan (2015)),…”

Section: Boundary Conditionsmentioning

confidence: 99%

The effect of large-scale magnetic field on outflow in ADAFs: an odd symmetry configuration

Samadi

Abbassi

2015

Mon. Not. R. Astron. Soc.

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We construct self-similar inflow-outflow solutions for a hot viscous-resistive accretion flow with large scale magnetic fields that have odd symmetry with respect to the equatorial plane in B θ , and even symmetry in B r and B φ . Following previous authors, we also assume that the polar velocity v θ is nonzero. We focus on four parameters: β r0 , β φ0 (the plasma beta parameters for associated with magnetic field components at the equatorial plane), the magnetic resistivity η 0 , and the density index n = −d ln ρ/d ln r. The resulting flow solutions are divided into two parts consisting of an inflow region with a negative radial velocity (v r < 0) and an outflow region with v r > 0. Our results show that stronger outflows emerge for smaller β r0 ( 10 −2 for n > 1) and larger values of β φ0 , η 0 and n.

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Two-dimensional inflow-wind solution of black hole accretion with an evenly symmetric magnetic field

Cited by 27 publications

References 41 publications

Faraday Rotation in the Jet of M87 inside the Bondi Radius: Indication of Winds from Hot Accretion Flows Confining the Relativistic Jet

Faraday Rotation in the Jet of M87 inside the Bondi Radius: Indication of Winds from Hot Accretion Flows Confining the Relativistic Jet

On the Role of the Hot Feedback Mode in Active Galactic Nuclei Feedback in an Elliptical Galaxy

The effect of large-scale magnetic field on outflow in ADAFs: an odd symmetry configuration

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