EPoS Contribution
EPoS Contribution
Formation of Molecular Clouds by Obliquely Colliding Flows

Bastian Koertgen
HS, Hamburg, DE
We present results from numerical simulations of the formation of molecular clouds by colliding oblique flows of the WNM. One flow is inclined with respect to the background magnetic field, thus giving rise to enhanced magnetic diffusivity as well as strong shear flows. We study the dynamics of the resulting molecular cloud complexes as function of the inclination angle and the initial magnetic field strength. We find that, for quite realistic initial field strengths of 5 muG, the star formation process is completely suppressed. An initial field strength of 3 muG leads to the formation of stars, but the onset of this process strongly depends on the initial inclination. We further find that the mass spectrum of those clouds is rather small with final masses comparable to those estimated for the Taurus, Perseus and Corona Australis clouds.
Caption: Left: Top view of the column density for an initial magnetic field strength of B=5microGauss. Red regions denote high, white regions low column densities. Black arrows show velocity field, light-blue lines mark the magnetic field. Right: Same as left, but for the case of B=3microGauss. As can be clearly seen, deep within the cloud complex, the weaker magnetic field is highly distorted and dominated by accretion flows towards the clumps within the cloud. In the case of a higher field strength, the field is mostly perpendicular to the cloud and the flow, thereby prohibiting larger accretion flows onto clumps and thus delaying/suppressing star formation.
Collaborators:
R. Banerjee, HS, Germany
Suggested Session: Molecular Clouds