Beta Viscosit Prescription in Self-Gravitating Disks
Duschl et al. (2000) have shown that the standard model for geometrically thin accretion disks (a-disks) leads to inconsistency if self-gravity play a role. This problem arise from parametrization of viscosity in terms of local sound velocity and vertical disks scale hight. The β-viscosity prescription was introduced by Duschl et al. (2000), which has been derived from rotating shear fiow experiment (ν) = βΩR2). Following the Duschl et al. (2000) suggestion for a β-prescription for viscosity, we apply this model for a thin self-gravitating disk around newborn stars. Our result is quite different with standard alpha disks in the outer part of the disks where the self-gravity becomes important. In the inner part of the disks, our solution converged to the standard a disks. It has been presented that for beta model, Toomre parameter is more than unity everywhere which means that gravitational fragmentation can be occur everywhere. We suggest that the kind of hydrodynamically driven viscosity,β model, can be used for modeling of accretion disks from protostellar disks to AGN and galactic disks. It would be interest to investigate ADAF-type solution for follow any effects by β-viscosity model. An important property of the pdisk is that they are viscously stable.
ISM molecules ISM structure instabilities
S. Abbassi J. Ghanbari
School of Physics, Damghan University of Basic Sciences, Damghan, P.O.Box 36715-364, Iran Department of Physics, Ferdowsi University of Maslhad, Mashhad, Iran
国际会议
The 10th Asian-Pacific Regional International Astronomical Union Meeting(第十届亚洲及太平洋地区天文学大会 APRIM)
昆明
英文
97-99
2008-08-03（万方平台首次上网日期，不代表论文的发表时间）