skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Anchoring Polar Magnetic Field in a Stationary Thick Accretion Disk

Abstract

We investigate the properties of a hot accretion flow bathed in a poloidal magnetic field. We consider an axisymmetric viscous-resistive flow in the steady-state configuration. We assume that the dominant mechanism of energy dissipation is due to turbulence viscosity and magnetic diffusivity. A certain fraction of that energy can be advected toward the central compact object. We employ the self-similar method in the radial direction to find a system of ODEs with just one varible, θ in the spherical coordinates. For the existence and maintenance of a purely poloidal magnetic field in a rotating thick disk, we find that the necessary condition is a constant value of angular velocity along a magnetic field line. We obtain an analytical solution for the poloidal magnetic flux. We explore possible changes in the vertical structure of the disk under the influences of symmetric and asymmetric magnetic fields. Our results reveal that a polar magnetic field with even symmetry about the equatorial plane makes the disk vertically thin. Moreover, the accretion rate decreases when we consider a strong magnetic field. Finally, we notice that hot magnetized accretion flows can be fully advected even in a slim shape.

Authors:
;  [1]
  1. Department of Physics, School of Sciences, Ferdowsi University of Mashhad, Mashhad, 91775-1436 (Iran, Islamic Republic of)
Publication Date:
OSTI Identifier:
22663213
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 845; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCRETION DISKS; ANALYTICAL SOLUTION; ANGULAR VELOCITY; ASYMMETRY; AXIAL SYMMETRY; ENERGY LOSSES; MAGNETIC FIELDS; MAGNETIC FLUX; MAGNETOHYDRODYNAMICS; SIMULATION; STEADY-STATE CONDITIONS; TURBULENCE

Citation Formats

Samadi, Maryam, and Abbassi, Shahram, E-mail: samadimojarad@um.ac.ir. Anchoring Polar Magnetic Field in a Stationary Thick Accretion Disk. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA81C1.
Samadi, Maryam, & Abbassi, Shahram, E-mail: samadimojarad@um.ac.ir. Anchoring Polar Magnetic Field in a Stationary Thick Accretion Disk. United States. doi:10.3847/1538-4357/AA81C1.
Samadi, Maryam, and Abbassi, Shahram, E-mail: samadimojarad@um.ac.ir. Sun . "Anchoring Polar Magnetic Field in a Stationary Thick Accretion Disk". United States. doi:10.3847/1538-4357/AA81C1.
@article{osti_22663213,
title = {Anchoring Polar Magnetic Field in a Stationary Thick Accretion Disk},
author = {Samadi, Maryam and Abbassi, Shahram, E-mail: samadimojarad@um.ac.ir},
abstractNote = {We investigate the properties of a hot accretion flow bathed in a poloidal magnetic field. We consider an axisymmetric viscous-resistive flow in the steady-state configuration. We assume that the dominant mechanism of energy dissipation is due to turbulence viscosity and magnetic diffusivity. A certain fraction of that energy can be advected toward the central compact object. We employ the self-similar method in the radial direction to find a system of ODEs with just one varible, θ in the spherical coordinates. For the existence and maintenance of a purely poloidal magnetic field in a rotating thick disk, we find that the necessary condition is a constant value of angular velocity along a magnetic field line. We obtain an analytical solution for the poloidal magnetic flux. We explore possible changes in the vertical structure of the disk under the influences of symmetric and asymmetric magnetic fields. Our results reveal that a polar magnetic field with even symmetry about the equatorial plane makes the disk vertically thin. Moreover, the accretion rate decreases when we consider a strong magnetic field. Finally, we notice that hot magnetized accretion flows can be fully advected even in a slim shape.},
doi = {10.3847/1538-4357/AA81C1},
journal = {Astrophysical Journal},
number = 2,
volume = 845,
place = {United States},
year = {Sun Aug 20 00:00:00 EDT 2017},
month = {Sun Aug 20 00:00:00 EDT 2017}
}