Magnetism in the nearby galaxy M33
  Using high-resolution data of the linearly polarized intensity and
polarization angle at 3.6, 6.2, and 20 cm together with a 3-D model of the
regular magnetic field, we study variations of the structure, strength, and
energy density of the magnetic field in the Scd galaxy M33. The regular
magnetic field consists of a horizontal component (represented by an
axisymmetric mode from 1 to 3 kpc radius and a superposition of axisymmetric
and bisymmetric modes from 3 to 5 kpc radius) and a vertical component.
However, the inferred `vertical field' may be partly due to a galactic warp. We
estimate the average total and regular magnetic field strengths as ~ 6.4 and
2.5 $\mu$G, respectively. Generation of interstellar magnetic fields by
turbulent gas motion in M33 is indicated as the turbulent and magnetic energy
densities are about equal.
