Impact Of Magnetic Fields On Molecular Cloud Formation & Evolution
  We use magnetohydrodynamical simulations of converging flows to investigate
the process of molecular cloud formation and evolution out of the magnetised
ISM. Here, we investigate whether the observed subcritical HI clouds can become
supercritical and hence allow the formation of stars within them. To do so, we
vary the turbulent Mach number of the flows, as well as the initial magnetic
field strength. We show that dense cores are able to build up under all
conditions, but that star formation in these cores is either heavily delayed or
completely suppressed if the initial field strength is B>3 microGauss. To probe
the effect of magnetic diffusion, we introduce a tilting angle between the
flows and the uniform background magnetic field, which mimics non--ideal MHD
effects. Even with highly inclined flows, the formed cores are devoid of star
formation, because no magnetically supercritical regions are build up. Hence we
conclude, that the problem of how supercritical cloud cores are generated still
persists.
