Unified description of black-hole accretion flows with convection.

作者：Lu JF^*; Gu WM

来源：Il Nuovo Cimento B Series 10, 2002, 117(7): 733-742.

We provide a unified description of black-hole accretion flows with convection, adopting that convection moves angular momentum inward. We work with one-dimensional vertically averaged equations arid seek self-similar solutions. For very small values of the viscosity parameter alpha < 0.01, we find that neither the slim disk nor the advection-dominated accretion flow (ADAF) exists because the inward flux of energy carried by advection has been overcome by the outward one carried by convection; instead, we obtain a "convection-dominated accretion flow" (CDAF) which is, however, thermally unstable. The instability of CDAF implies one more possible behavior in the inner zone of an original Shakura-Sunyaev disk (SSD) flow, namely runaway, in addition to the three known possibilities presented in the literature, i.e. limit cycle, SSD-ADAF transition, au d stable SSD. The current discrepancy between the results of one-dimensional studies including ours and that of multidimensional numerical simulations of accretion flows is noticed and briefly discussed.

• 出版日期2002-7
• 单位厦门大学