The Collisions of HVCs with a Magnetized Gaseous Galactic Disk

We discuss 2-D MHD numerical simulations for the interaction of high-velocit y clouds with a magnetized Galactic disk. The initial magnetic field is oriented parallel to the disk, and we consider two different field topologies: parallel and perpendicular to the plane of motion of the clouds. The imp...

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Detalles Bibliográficos
Autores: Alfredo Santillán, Marco Martos, José Franco, Jongsoo Kim
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2001
País:México
Institución:Universidad Nacional Autónoma de México
Repositorio:Redalyc-UNAM
OAI Identifier:oai:redalyc.org:57101122
Acceso en línea:https://www.redalyc.org/articulo.oa?id=57101122
Access Level:acceso abierto
Palabra clave:Física, Astronomía y Matemáticas
Descripción
Sumario:We discuss 2-D MHD numerical simulations for the interaction of high-velocit y clouds with a magnetized Galactic disk. The initial magnetic field is oriented parallel to the disk, and we consider two different field topologies: parallel and perpendicular to the plane of motion of the clouds. The impinging clouds move in oblique trajectories and fall toward the plane with different initial velocities. The B-field lines are distorted and compressed during the collision, preventing the cloud from penetrating into the disk. The perturbation creates a complex, turbulent, pattern of MHD waves that induce oscillations on both sides of the plane, and can trigger the Parker instability . The field efficiently transmits the perturbation over a large volume, while acting like a shield that inhibits the mass exchange between halo and disk. For non-magnetized disk cases, the shocked layer generates a tail that oscillates, creating vorticity and turbulent flows along its trajectory.