English

The 2D disk structure with advective transonic inflow-outflow solutions around black holes

High Energy Astrophysical Phenomena 2018-07-04 v1

Abstract

We solved analytically viscous two-dimensional (2D) fluid equations for accretion and outflows in spherical polar coordinates (r,θ,ϕr, \theta, \phi) and obtained explicitly flow variables in rr- and θ\theta -directions around black holes (BHs). We investigated global transonic advection-dominated accretion flow (ADAF) solutions in rr-direction on an equatorial plane with using Paczy\'nski-Wiita potential. We used radial flow variables of ADAFs with symmetric conditions on the equatorial plane, as initial values for integration in θ\theta-direction. In the study of 2D disk structure, we used two-azimuthal components of viscous stress tensors namely, τrϕ\tau_{\rm r\phi} and τθϕ\tau_{\rm\theta\phi}. Interestingly, we found that the whole advective disk is not participating in outflow generation and the outflows form close to the BHs. Normally, outflow strength increased with increasing viscosity parameter (α1\alpha_1), mass-loss parameter (ss) and decreasing gas pressure ratio (β\beta). Outflow region increased with increasing ss, α1\alpha_1 for τrϕ\tau_{\rm r\phi} and decreasing α2\alpha_2 for τθϕ\tau_{\rm\theta\phi}. The τθϕ\tau_{\rm\theta\phi} is effective in angular momentum transportation at high latitude and outflows collimation along an axis of symmetry since it changes polar velocity (vθv_{\rm\theta}) of the flow. The outflow emission is also affected by the ADAF size and decreased with decreasing it. Transonic surfaces formed for both inflows (vr<0v_{\rm r}<0, very close to BH) and outflows (vr>0v_{\rm r}>0). We also explored no outflows, outflows and failed outflows regions, which mainly depend on the viscosity parameters.

Keywords

Cite

@article{arxiv.1805.02844,
  title  = {The 2D disk structure with advective transonic inflow-outflow solutions around black holes},
  author = {Rajiv Kumar and Wei-Min Gu},
  journal= {arXiv preprint arXiv:1805.02844},
  year   = {2018}
}

Comments

22 pages, 9 figures, Accepted for publication in ApJ