Abstract
We apply our two-dimensional (2D), radially self-similar steady-state accretion flow model to the analysis of hydrodynamic simulation results of supercritical accretion flows. Self-similarity is checked and the input parameters for the model calculation, such as advective factor and heat capacity ratio, are obtained from time-averaged simulation data. Solutions of the model are then calculated and compared with the simulation results. We find that in the converged region of the simulation, excluding the part too close to the black hole, the radial distributions of azimuthal velocity v(phi), density rho and pressure p basically follow the self-similar assumptions, i.e., they are roughly proportional to r(-0.5), r(-n), and r(-(n+1)), respectively, where n similar to 0.85 for the mass injection rate of 1000L(E) lc(2), and n similar to 0.74 for 3000L(E) lc(2) . The distribution of vr and v(theta) agrees less with self-similarity, possibly due to convective motions in the r(theta) plane. The distribution of velocity, density, and pressure in the. direction obtained by the steady model agrees well with the simulation results within the calculation boundary of the steady model. Outward mass flux in the simulations is overall directed toward a polar angle of 0.8382 rad (similar to 48 degrees.0) for 1000L(E)lc(2) and 0.7852 rad (similar to 43 degrees.4) for 3000L(E)lc(2) and similar to 94% of the mass inflow is driven away as outflow, while outward momentum and energy fluxes are focused around the polar axis. Parts of these fluxes lie in the region that is not calculated by the steady model, and special attention should be paid when the model is applied.
Original language | English |
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Article number | 93 |
Pages (from-to) | 1-18 |
Number of pages | 18 |
Journal | Astrophysical Journal |
Volume | 806 |
Issue number | 1 |
DOIs | |
Publication status | Published - 10 Jun 2015 |
Externally published | Yes |
Keywords
- accretion, accretion discs
- black hole physics
- hydrodynamics