Molecular cloud formation in high-shear, magnetized colliding flows
  The colliding flows (CF) model is a well-supported mechanism for generating
molecular clouds. However, to-date most CF simulations have focused on the
formation of clouds in the normal-shock layer between head-on colliding flows.
We performed simulations of magnetized colliding flows that instead meet at an
oblique-shock layer. Oblique shocks generate shear in the post-shock
environment, and this shear creates inhospitable environments for star
formation. As the degree of shear increases (i.e. the obliquity of the shock
increases), we find that it takes longer for sink particles to form, they form
in lower numbers, and they tend to be less massive. With regard to magnetic
fields, we find that even a weak field stalls gravitational collapse within
forming clouds. Additionally, an initially oblique collision interface tends to
reorient over time in the presence of a magnetic field, so that it becomes
normal to the oncoming flows. This was demonstrated by our most oblique shock
interface, which became fully normal by the end of the simulation.
