论文标题
电阻积聚在Kerr黑洞周围流动
Resistive Accretion Flows around a Kerr Black Hole
论文作者
论文摘要
在本文中,我们介绍了在外部重力附近的电阻磁化厚积聚盘和缓慢旋转黑洞的固有偶极磁场的固定轴对称构型。血浆由完全一般相对论的磁性水力学(MHD)以及欧姆定律以及没有辐射场的影响的方程来描述。我们尝试在分析上尽可能分析地求解这些二维MHD方程。但是,有时我们不可避免地也指数值方法。为了充分理解相对论的几何厚积聚盘结构,我们认为流体速度的所有三个组成部分都是非零的。这意味着磁性流体可以在中央黑洞周围的所有三个方向上流动。当我们径向接近孔时,流体在所有这些方向上流动更快。但是,当我们沿着子午方向向赤道移动时,径向流入从速度和质量积聚率的观点变得更加强大。但是,垂直(子午)速度和等离子体盘的旋转在该方向上变慢。由于存在压力梯度力,也期望在整个厚度圆盘中均可缩小的角动量分布。为了获得积聚速率的简明分析形式,我们假设径向和子午流体速度的径向依赖性相同。这种简化的假设导致质量积聚率的径向独立性。积聚等离子体的运动产生的方位角电流,其强度是根据外部偶极磁场的强度指定的。该电流在椎间盘中产生一个多型磁场,由于血浆的有限电阻率,该电流在整个圆盘边界表面连续连续。
In this paper, we present the stationary axisymmetric configuration of a resistive magnetised thick accretion disc in the vicinity of external gravity and intrinsic dipolar magnetic field of a slowly rotating black hole. The plasma is described by the equations of fully general relativistic magnetohydrodynamics (MHD) along with the Ohm's law and in the absence of the effects of radiation fields. We try to solve these two-dimensional MHD equations analytically as much as possible. However, we sometimes inevitably refer to numerical methods as well. To fully understand the relativistic geometrically thick accretion disc structure, we consider all three components of the fluid velocity to be non-zero. This implies that the magnetofluid can flow in all three directions surrounding the central black hole. As we get radially closer to the hole, the fluid flows faster in all those directions. However, as we move towards the equator along the meridional direction, the radial inflow becomes stronger from both the speed and the mass accretion rate points of view. Nonetheless, the vertical (meridional) speed and the rotation of the plasma disc become slower in that direction. Due to the presence of pressure gradient forces, a sub-Keplerian angular momentum distribution throughout the thick disc is expected as well. To get a concise analytical form of the rate of accretion, we assume that the radial dependency of radial and meridional fluid velocities is the same. This simplifying assumption leads to radial independency of mass accretion rate. The motion of the accreting plasma produces an azimuthal current whose strength is specified based on the strength of the external dipolar magnetic field. This current generates a poloidal magnetic field in the disc which is continuous across the disc boundary surface due to the presence of the finite resistivity for the plasma.