Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-01-28
Astrophys.J. 597 (2003) 131-141
Astronomy and Astrophysics
Astrophysics
16 pages, 11 figures, aastex 5.0, to appear in ApJ
Scientific paper
10.1086/320631
Thin, Keplerian accretion disks generically become gravitationally unstable at large radius. I investigate the nonlinear outcome of such instability in cool disks using razor-thin, local, numerical models. Cooling, characterized by a constant cooling time t_c, drives the instability. I show analytically that, if the disk can reach a steady state in which heating by dissipation of turbulence balances cooling, then the dimensionless angular momentum flux density \alpha = ((9/4) \gamma (\gamma-1) \Omega t_c)^{-1}. Numerical experiments show that: (1) if t_c \gtrsim 3\Omega^{-1} then the disk reaches a steady, gravito-turbulent state in which Q \sim 1 and cooling is balanced by heating due to dissipation of turbulence; (2) if t_c \lesssim 3\Omega^{-1}, then the disk fragments, possibly forming planets or stars; (3) in a steady, gravito-turbulent state, surface density structures have a characteristic physical scale \sim 64 G \Sigma/\Omega^2 that is independent of the size of the computational domain.
No associations
LandOfFree
Nonlinear Outcome of Gravitational Instability in Cooling, Gaseous Disks does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Nonlinear Outcome of Gravitational Instability in Cooling, Gaseous Disks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nonlinear Outcome of Gravitational Instability in Cooling, Gaseous Disks will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-309508