The near universality of DM halo density profiles provided by N-body simulations has proven to be robust against changes in total mass density , power spectrum , and some forms of initial velocity dispersion .
In this letter we study the effects of coherently spinning up an isolated DM-only progenitor on halo structure .
Halos with spins within several standard deviations of the simulated mean ( \lambda \lesssim 0.20 ) produce profiles with negligible deviations from the universal form .
Only when the spin becomes quite large ( \lambda \gtrsim 0.20 ) do departures become evident .
The angular momentum distribution also exhibits a near universal form , which is also independent of halo spin up to \lambda \lesssim 0.20 .
A correlation between these epidemic profiles and the presence of a strong bar in the virialized halo is also observed .
These bar structures bear resemblance to the radial orbit instability in the rotationless limit .