TY - JOUR

T1 - Mechanisms of the vertical secular heating of a stellar disk

AU - Sotnikova, N. Ya.

AU - Rodionov, S. A.

PY - 2003

Y1 - 2003

N2 - We investigate the nonlinear growth stages of the bending instability in stellar disks with exponential radial density profiles. We found that the unstable modes are global (the wavelengths are larger than the disk scale lengths) and that the instability saturation level is much higher than that following from a linear criterion. The instability saturation time scales are of the order of one billion years or more. For this reason, the bending instability can play an important role in the secular heating of a stellar disk in the z direction. In an extensive series of numerical N-body simulations with a high spatial resolution, we were able to scan in detail the space of key parameters (the initial disk thickness z_0, the Toomre parameter Q, and the ratio of dark halo mass to disk mass M_h/M_d). We revealed three distinct mechanisms of disk heating in the z direction: bending instability of the entire disk, bending instability of the bar, and heating on vertical inhomogeneities in the distribution of stellar ma

AB - We investigate the nonlinear growth stages of the bending instability in stellar disks with exponential radial density profiles. We found that the unstable modes are global (the wavelengths are larger than the disk scale lengths) and that the instability saturation level is much higher than that following from a linear criterion. The instability saturation time scales are of the order of one billion years or more. For this reason, the bending instability can play an important role in the secular heating of a stellar disk in the z direction. In an extensive series of numerical N-body simulations with a high spatial resolution, we were able to scan in detail the space of key parameters (the initial disk thickness z_0, the Toomre parameter Q, and the ratio of dark halo mass to disk mass M_h/M_d). We revealed three distinct mechanisms of disk heating in the z direction: bending instability of the entire disk, bending instability of the bar, and heating on vertical inhomogeneities in the distribution of stellar ma

KW - galaxies - groups and clusters of galaxies - intergalactic gas

U2 - 10.1134/1.1573281

DO - 10.1134/1.1573281

M3 - Article

VL - 29

SP - 321

EP - 335

JO - Astronomy Letters

JF - Astronomy Letters

SN - 1063-7737

IS - 5

ER -