EPoS Contribution
EPoS Contribution
Core Formation in Filaments under the Influence of Turbulence and Large Scale Velocity Gradients

Stefan Heigl
LMU/MPE, Munich, DE
Filaments rarely form in isolation but are assumed to be embedded in an external medium. The gravitational attraction of the filament itself should lead to the accretion of the surrounding medium. In a first study without the inclusion of self-gravity we showed that this accretion process is a driver of turbulence and can account for the non-thermal line widths observed in filaments. The accretion leads to non-isotropic, radially dominated turbulent motions. The absolute velocity dispersion scales linearly with the accretion velocity. In a new study, we now include("he1.php"); prevent a filament from collapsing once it is above the critical line-mass. In addition to a non-thermal line width component, filaments are often observed to have linear velocity gradients along the axis. Our most recent work focusses on explaining observations of filaments which show a twist-up of gas around a core in an otherwise straight filament. We show that cores forming from filament gas with a linear velocity gradient are dominated by the conservation of angular momentum. In addition to a twisted morphology, they develop a prominent, but observationally unresolvable disk in the plane of the velocity gradient. We predict that this morphology should be an archetype for cores forming in filaments with a linear velocity gradient.
Caption: Core forming in a filament with a linear density gradient.
Collaborators:
A. Burkert, LMU/MPE, DE
M. Gritschneder, LMU, DE
Key publication

Suggested Session: Filaments