The Southern Vilnius Photometric System. IV. The E Regions Standard Stars

This paper is the fourth in a series on the extension of the Vilnius photometric system to the southern hemisphere. Observations were made of 60 stars in the Harvard Standard E regions to increase a set of standard stars.Comment: 6 pages, TeX, requires 2 macros (baltic2.tex, baltic4.tex) included no figures, to be published in Baltic Astronomy, Vol 6, pp1-6 (1997

Diamonds on the Hat: Globular Clusters in The Sombrero Galaxy (M104)

Images from the HST ACS are used to carry out a new photometric study of the globular clusters (GCs) in M104, the Sombrero galaxy. The primary focus of our study is the characteristic distribution function of linear sizes (SDF) of the GCs. We measure the effective radii for 652 clusters with PSF-convolved King and Wilson dynamical model fits. The SDF is remarkably similar to those measured for other large galaxies of all types, adding strong support to the view that it is a "universal" feature of globular cluster systems. We develop a more general interpretation of the size distribution function for globular clusters, proposing that the shape of the SDF that we see today for GCs is strongly influenced by the early rapid mass loss during their star forming stage, coupled with stochastic differences from cluster to cluster in the star formation efficiency (SFE) and their initial sizes. We find that the observed SDF shape can be accurately predicted by a simple model in which the protocluster clouds had characteristic sizes of $0.9 \pm 0.1$ pc and SFEs of $0.3 \pm 0.07$. The colors and luminosities of the M104 clusters show the clearly defined classic bimodal form. The blue sequence exhibits a mass/metallicity relation (MMR), following a scaling of heavy-element abundance with luminosity of $Z \sim L^{0.3}$ very similar to what has been found in most giant elliptical galaxies. A quantitative self-enrichment model provides a good first-order match to the data for the same initial SFE and protocluster size that were required to explain the SDF. We also discuss various forms of the globular cluster Fundamental Plane (FP) of structural parameters, and show that useful tests of it can be extended to galaxies beyond the Local Group.Comment: In press for MNRA

The Electrosphere of Macroscopic "Quark Nuclei": A Source for Diffuse MeV Emissions from Dark Matter

Using a Thomas-Fermi model, we calculate the structure of the electrosphere of the quark antimatter nuggets postulated to comprise much of the dark matter. This provides a single self-consistent density profile from ultrarelativistic densities to the nonrelativistic Boltzmann regime that use to present microscopically justified calculations of several properties of the nuggets, including their net charge, and the ratio of MeV to 511 keV emissions from electron annihilation. We find that the calculated parameters agree with previous phenomenological estimates based on the observational supposition that the nuggets are a source of several unexplained diffuse emissions from the Galaxy. As no phenomenological parameters are required to describe these observations, the calculation provides another nontrivial verification of the dark-matter proposal. The structure of the electrosphere is quite general and will also be valid at the surface of strange-quark stars, should they exist.Comment: 20 Pages, REVTeX4.

Species of root maggots (Diptera: Anthomyiidae) of cruciferous crops in British Columbia

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Prepotentials for local mirror symmetry via Calabi-Yau fourfolds

In this paper, we first derive an intrinsic definition of classical triple intersection numbers of K_S, where S is a complex toric surface, and use this to compute the extended Picard-Fuchs system of K_S of our previous paper, without making use of the instanton expansion. We then extend this formalism to local fourfolds K_X, where X is a complex 3-fold. As a result, we are able to fix the prepotential of local Calabi-Yau threefolds K_S up to polynomial terms of degree 2. We then outline methods of extending the procedure to non canonical bundle cases.Comment: 42 pages, 7 figures. Expanded, reorganized, and added a theoretical background for the calculation

WMAP Haze: Directly Observing Dark Matter?

In this paper we show that dark matter in the form of dense matter/antimatter nuggets could provide a natural and unified explanation for several distinct bands of diffuse radiation from the core of the Galaxy spanning over 12 orders of magnitude in frequency. We fix all of the phenomenological properties of this model by matching to x-ray observations in the keV band, and then calculate the unambiguously predicted thermal emission in the microwave band, at frequencies smaller by 10 orders of magnitude. Remarkably, the intensity and spectrum of the emitted thermal radiation are consistent with--and could entirely explain--the so-called "WMAP haze": a diffuse microwave excess observed from the core of our Galaxy by the Wilkinson Microwave Anisotropy Probe (WMAP). This provides another strong constraint of our proposal, and a remarkable nontrivial validation. If correct, our proposal identifies the nature of the dark matter, explains baryogenesis, and provides a means to directly probe the matter distribution in our Galaxy by analyzing several different types of diffuse emissions.Comment: 16 pages, REVTeX4. Updated to correspond with published version: includes additional appendices discussing finite-size effect

Chemical control of root maggots in early cabbage

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Zonal mean and tidal dynamics from space: An empirical examination of aliasing and sampling issues

Interpretations of space-based measurements of atmospheric parameters in the mesosphere and thermosphere are complicated by large local-time variations at these altitudes. For this reason, satellite orbits are often preferred which precess through all local times one or more times per season. However, the local-time structure of the atmosphere is inherently non-stationary, which can lead to sampling and aliasing difficulties when attempting to deconvolve the measurements into zonal mean and tidal components. In the present study, hourly radar measurements of mesopause-region winds are used to form a mock data base which can be used to gain insight into implications of the aforementioned problems; the use of actual measurements introduces a realistic element of geophysical temporal variability. Assuming zonal symmetry (i.e., migrating tides superimposed on a zonal mean circulation), the radar measurements are sampled from the satellite perspective for orbital inclinations of 57° and 70°, and compared to the ground or true perspective. These comparisons provide realistic estimates of the errors to be expected when attempting to derive mean and tidal components from space-based measurements. For both diurnal and semidiurnal components, and the quoted satellite inclinations, acceptable errors (3–4m/srms) are obtained for data covering 24h local time (i.e., ascending plus descending nodes); the corresponding errors for single-node data (12h local-time coverage) are of order 8–11m/s, and therefore may not represent reliable estimates of the actual tidal components. There exist certain caveats in connection with the latter conclusion which are discussed