Non-linear evolution of the angular momentum of protostructures from tidal torques

Abstract:

We discuss the non-linear evolution of the angular momentum L acquired by protostructures, like protogalaxies and protoclusters, due to tidal interactions with the surrounding matter inhomogeneities. The primordial density distribution is assumed to be Gaussian, and the non-linear dynamics of the collisionless mass fluid is followed using Lagrangian perturbation theory. For a cold dark matter spectrum, the inclusion of the leading-order Lagrangian correction terms results in a value of the rms ensemble average 〈L2〉1/2 which is only a factor of 1.3 higher than the corresponding linear estimate, irrespective of the scale. Consequently, the pbkp_redictions of linear theory are rather accurate in quantifying the evolution of the angular momentum of protostructures before collapse sets in. In the Einstein-de Sitter universe, the initial torque is a good estimate for the tidal torque over the whole period during which the object is spun up.

Año de publicación:

1996

Keywords:

• Galaxies: formation
• Large-scale structure of universe

Fuente:

scopus