We report Faraday rotation measurements of 11 extragalactic radio sources with lines of sight through the Rosette Nebula, a prominent H ii region associated with the star cluster NGC 2244. The goal of these measurements is to better determine the strength and structure of the magnetic field in the nebula. We calculate the rotation measure (RM) through two methods, a least-squares fit to χ(λ 2 ) and Rotation Measure Synthesis. In conjunction with our results from Savage et al. (2013), we find an excess RM due to the shell of the nebula of +40 to +1200 rad m −2 above a background RM of +147 rad m −2 . We discuss two forms of a simple shell model intended to reproduce the magnitude of the observed RM as a function of distance from the center of the Rosette Nebula. The models represent different physical situations for the magnetic field within the shell of the nebula. The first assumes that there is an increase in the magnetic field strength and plasma density at the outer radius of the H ii region, such as would be produced by a strong magnetohydrodynamic shock wave. The second model assumes that any increase in the RM is due solely to an increase in the density, and the Galactic magnetic field is unaffected in the shell. We employ a Bayesian analysis to compare the two forms of the model. The results of this analysis were inconclusive, although the model without amplification of the interstellar magnetic field is weakly favored.

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Suitable tight-binding models for wurtzite III–V (non-nitride) and group-V materials are presently missing in the literature. Many commonly used nearest neighbor tight-binding models for cubic-zincblende semiconductors result in highly inaccurate band structures when transferred to hexagonal polytypes. Wurtzite parameters would be of use in modeling nanowires that primarily condense into either wurtzite or zincblende crystal phases. Nanowire growth has seen significant development over the last decade, and polytypic heterostructures are now able to be fabricated. We have produced a set of spds* tight-binding parameters to be used in the hexagonal-wurtzite crystal phase for non-nitride III–V and group V semiconductors. We confine our parameter space to remain in the vicinity of a well-established zincblende parameter set to ensure semi-transferability between the wurtzite and zincblende polytypes. Our wurtzite parameters, when combined with the existing zincblende parameters, enable modeling electronic structures of heterostructures containing both the wurtzite and zincblende crystal phases.

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