scholarly journals Exploring the jet/accretion flow relationship in low disk luminosity sources

2007 ◽  
pp. 189-195
Author(s):  
Sera Markoff
Keyword(s):  
Accretion Flow

scholarly journals Influence of the geometric configuration of accretion flow on the black hole spin dependence of relativistic acoustic geometry

2018 ◽  
Vol 27 (03) ◽  
pp. 1850023 ◽  
Author(s):  
Pratik Tarafdar ◽  
Tapas K. Das
Keyword(s):  
Black Hole ◽  
Kerr Black Hole ◽  
Geometric Configuration ◽  
Surface Gravity ◽  
Linear Perturbation ◽  
Flow Profile ◽  
White Hole ◽  
Accretion Flow ◽  
Black Hole Spin ◽  
General Relativistic

Linear perturbation of general relativistic accretion of low angular momentum hydrodynamic fluid onto a Kerr black hole leads to the formation of curved acoustic geometry embedded within the background flow. Characteristic features of such sonic geometry depend on the black hole spin. Such dependence can be probed by studying the correlation of the acoustic surface gravity [Formula: see text] with the Kerr parameter [Formula: see text]. The [Formula: see text]–[Formula: see text] relationship further gets influenced by the geometric configuration of the accretion flow structure. In this work, such influence has been studied for multitransonic shocked accretion where linear perturbation of general relativistic flow profile leads to the formation of two analogue black hole-type horizons formed at the sonic points and one analogue white hole-type horizon which is formed at the shock location producing divergent acoustic surface gravity. Dependence of the [Formula: see text]–[Formula: see text] relationship on the geometric configuration has also been studied for monotransonic accretion, over the entire span of the Kerr parameter including retrograde flow. For accreting astrophysical black holes, the present work thus investigates how the salient features of the embedded relativistic sonic geometry may be determined not only by the background spacetime, but also by the flow configuration of the embedding matter.

scholarly journals The effects of magnetic field strength on the properties of wind generated from hot accretion flow

2018 ◽  
Vol 615 ◽  
pp. A35 ◽  
Author(s):  
De-Fu Bu ◽  
Amin Mosallanezhad
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Pressure Gradient ◽  
Magnetic Field Strength ◽  
Magnetic Pressure ◽  
Gas Pressure ◽  
Accretion Flow ◽  
Accretion Flows ◽  
Black Hole Accretion ◽  
The Magnetic Field

Context. Observations indicate that wind can be generated in hot accretion flow. Wind generated from weakly magnetized accretion flow has been studied. However, the properties of wind generated from strongly magnetized hot accretion flow have not been studied. Aims. In this paper, we study the properties of wind generated from both weakly and strongly magnetized accretion flow. We focus on how the magnetic field strength affects the wind properties. Methods. We solve steady-state two-dimensional magnetohydrodynamic equations of black hole accretion in the presence of a largescale magnetic field. We assume self-similarity in radial direction. The magnetic field is assumed to be evenly symmetric with the equatorial plane. Results. We find that wind exists in both weakly and strongly magnetized accretion flows. When the magnetic field is weak (magnetic pressure is more than two orders of magnitude smaller than gas pressure), wind is driven by gas pressure gradient and centrifugal forces. When the magnetic field is strong (magnetic pressure is slightly smaller than gas pressure), wind is driven by gas pressure gradient and magnetic pressure gradient forces. The power of wind in the strongly magnetized case is just slightly larger than that in the weakly magnetized case. The power of wind lies in a range PW ~ 10−4–10−3 Ṁinc2, with Ṁin and c being mass inflow rate and speed of light, respectively. The possible role of wind in active galactic nuclei feedback is briefly discussed.

scholarly journals Hot accretion flow in black hole binaries: a link connecting X-rays to the infrared

2013 ◽  
Vol 430 (4) ◽  
pp. 3196-3212 ◽  
Author(s):  
Alexandra Veledina ◽  
Juri Poutanen ◽  
Indrek Vurm
Keyword(s):  
Black Hole ◽  
X Rays ◽  
Black Hole Binaries ◽  
Accretion Flow

scholarly journals Effects of accretion flow on the chemical structure in the inner regions of protoplanetary disks

2008 ◽  
Vol 495 (1) ◽  
pp. 183-188 ◽  
Author(s):  
H. Nomura ◽  
Y. Aikawa ◽  
Y. Nakagawa ◽  
T. J. Millar
Keyword(s):  
Chemical Structure ◽  
Protoplanetary Disks ◽  
Accretion Flow

scholarly journals A Monte Carlo study of the spectra from inhomogeneous accretion flow

2017 ◽  
Vol 17 (8) ◽  
pp. 086
Author(s):  
Xiao-Di Yu ◽  
Ya-Ping Li ◽  
Fu-Guo Xie ◽  
Ren-Yi Ma
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Study ◽  
Accretion Flow

scholarly journals Mass-ratio and Magnetic Flux Dependence of Modulated Accretion from Circumbinary Disks

2021 ◽  
Vol 922 (2) ◽  
pp. 175
Author(s):  
Scott C. Noble ◽  
Julian H. Krolik ◽  
Manuela Campanelli ◽  
Yosef Zlochower ◽  
Bruno C. Mundim ◽  
...  
Keyword(s):  
Black Holes ◽  
Magnetic Flux ◽  
Internal Stress ◽  
Light Output ◽  
Threshold Value ◽  
Periodic Signal ◽  
Mass Ratio ◽  
Binary Black Holes ◽  
Accretion Flow ◽  
Forming Simulations

Abstract Accreting supermassive binary black holes (SMBBHs) are potential multimessenger sources because they emit both gravitational-wave and electromagnetic (EM) radiation. Past work has shown that their EM output may be periodically modulated by an asymmetric density distribution in the circumbinary disk, often called an “overdensity” or “lump;” this modulation could possibly be used to identify a source as a binary. We explore the sensitivity of the overdensity to SMBBH mass ratio and magnetic flux through the accretion disk. We find that the relative amplitude of the overdensity and its associated EM periodic signal both degrade with diminishing mass ratio, vanishing altogether somewhere between 1:2 and 1:5. Greater magnetization also weakens the lump and any modulation of the light output. We develop a model to describe how lump formation results from internal stress degrading faster in the lump region than it can be rejuvenated through accretion inflow, and predicts a threshold value in specific internal stress below which lump formation should occur and which all our lump-forming simulations satisfy. Thus, detection of such a modulation would provide a constraint on both mass ratio and magnetic flux piercing the accretion flow.

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