  In a prior paper (Kim et al. 2015) we considered the linear stability of
magnetized jets that carry no net electric current and do not have current
sheets. In this paper, in addition to physically well-motivated magnetic field
structures, we also include the effects of jet shear. The jets we study have
finite thermal pressure in addition to having realistic magnetic field
structures and velocity shear. We find that shear has a strongly stabilizing
effect on various modes of jet instability. Increasing shear stabilizes the
fundamental pinch modes at long wavelengths and short wavelengths. Increasing
shear also stabilizes the first reflection pinch modes at short wavelengths.
Increasing shear has only a very modest stabilizing effect on the fundamental
kink modes at long wavelengths; however, increasing shear does have a strong
stabilizing effect on the fundamental kink modes at short wavelengths. The
first reflection kink modes are strongly stabilized by increasing shear at
shorter wavelengths. Overall, we find that the combined effect of magnetic
field and shear stabilizes jets more than shear alone. In addition to the
results from a formal linear stability analysis, we present a novel way of
visualizing and understanding jet stability. This gives us a deeper
understanding of the enhanced stability of sheared, magnetized jets. We also
emphasize the value of our numerical approach in understanding the linear
stability of jets with realistic structure.
