Numerical Simulations of Astrophysical Jets from Keplerian Disks with Periodic Ejection

We present 2.5-dimensional time-dependent simulations of nonrelativistic andnonradiative outflows from sinusoidally perturbed Keplerian accretion disks. Asinusoidal perturbation is introduced in the velocity of the gas ejected fromthe surface of the disk into a cold corona. In the simulations, the disk is afixed boundary from which the gas is ejected with a pulsed velocity. Themaximum value of this velocity is taken to be a thousandth of the localKeplerian disk velocity. It was found that for large periods, the structures inthe jet tend to fragment into smaller substructures. For small values of theperiod, the structures tend to dissipate, while for medium values of theperiod, they tend to persist.Comment: 27 pages, 11 figures (by e-mail to braulo@astro.iag.usp.br), accepted for publication in Ap