The Effect of Rotational Gravity Darkening on Magnetically Torqued Be Star Disks

In the magnetically torqued disk (MTD) model for hot star disks, as proposed and formulated by \citet{cassi02}, stellar wind mass loss was taken to be uniform over the stellar surface. Here account is taken of the fact that as stellar spin rate S_o (=\sqrt {\Omega_o^2 R^3/GM}) is increased, and the stellar equator is gravity darkened, the equatorial mass flux and terminal speed are reduced, compared to the poles, for a given total \mdot. As a result, the distribution of equatorial disk density, determined by the impact of north and southbound flows, is shifted further out from the star. This results, for high S_o (\gtrsim 0.5), in a fall in the disk mass and emission measure, and hence in the observed emission line EW, scattering polarization, and IR emission. Consequently, contrary to expectations, critical rotation S_o \to 1 is not the optimum for creation of hot star disks which, in terms of EM for example, is found to occur in a broad peak around S_o\approx 0.5-0.6 depending slightly on the wind velocity law. The relationship of this analytic quasi-steady parametric MTD model to other work on magnetically guided winds is discussed. In particular the failures of the MTD model for Be-star disks alleged by \citet{owo03} are shown to revolve largely around open observational tests, rather in the basic MTD physics, and around their use of insufficiently strong fields.Comment: 25 pages with 11 figures, accepted by MNRA

An Interdisciplinary Approach to the Urban Streetscape of Budapest's Andrassy Ut

As Budapest's most prominent boulevard, Andrassy Ut (Andrassy Way) exhibits a variety of urban land uses designed to showcase Hungarian history and culture and provide modern housing and leisure amenities for the city's elite. Designed and constructed in the 1870s, it is anchored in by Erzsebet tor (Erzsebet Square) in the city center and extends 2.42 km (1.5 mi) northeast to Varosliget (City Park). This study, conducted in summer 2014 by students in UW-Eau Claire's interdisciplinary Central European Travel Seminar (CETS), examined the cultural streetscape of the boulevard through the lens of geography, history, and music. Teams of researchers were dispatched to designated stretches of Andrassy Ut to document the ways in which historically and musically significant buildings and institutions coincide with high-end residential and commercial land uses. Landscape analysis was then utilized to document concentrations of specific types of land uses. As the city embarks on a massive redevelopment project that will convert Andrassy Ut from mixed use corridor into the tourism-focused Andrassy Quarter, this study marks an important transition period in the boulevard's history