Gravitational Instability in Neutrino Dominated Accretion Disks  

作　　者：LIU Tong XUE Li 刘彤;薛力(Department of Physics and Institute of Theoretical Physics and Astrophysics,Xiamen University,Xiamen 361005)

机构地区：[1]Department of Physics and Institute of Theoretical Physics and Astrophysics,Xiamen University,Xiamen 361005

出　　处：《Chinese Physics Letters》2011年第12期309-311,共3页中国物理快报（英文版）

基　　金：Supported by the National Basic Research Program of China under Grant No 2009CB824800;the National Natural Science Foundation of China under Grant Nos 10833002,11003016,11073015 and 11103015;the Natural Science Foundation of Fujian Province of China under Grant No 2010J01017.

摘　　要：We revisit the vertical structure of neutrino-dominated accretion flows(NDAFs)in spherical coordinates under a boundary condition based on a mechanical equilibrium.The solutions show that the NDAF is significantly geometrically thick.The Toomre parameter is determined by the mass accretion rate and the viscosity parameter,which is defined as Q=cSΩ/πGΣ,where cS,ΩandΣare the sound speed,angular velocity and surface density,respectively.According to the distribution of the Toomre parameter,the possible fragments of the disk may appear near the disk surface in the outer region.These possible outflows originating from the gravitational instability of the disk may account for the late-time flares in gamma-ray bursts.

关 键 词：PARAMETER VISCOSITY COORDINATES 

分 类 号：O57[理学—粒子物理与原子核物理]