Most of the globular clusters in the main body of the Galactic halo were formed almost simultaneously. However, globular cluster formation in dwarf spheroidal galaxies appears to have extended over a significant fraction of a Hubble time. This suggests that the factors which suppressed late-time formation of globulars in the main body of the Galactic halo were not operative in dwarf spheroidal ...

We propose a simple model for the formation of dwarf spheroidal galaxies, in which stars are assumed to have formed from isothermal gas in hydrostatic equilibrium inside extended dark matter halos. After expelling the leftover gas, the stellar system undergoes a dynamical relaxation inside the dark matter halo. These models can adequately describe the observed properties of three (Draco, Sculpt...

An algorithm for the generation of non-uniform, locally orthogonal staggered unstructured spheroidal grids is described. This technique is designed to generate very high-quality staggered Voronoi–Delaunay meshes appropriate for general circulation modelling on the sphere, including applications to atmospheric simulation, ocean-modelling and numerical weather prediction. Using a recently develop...

An algorithm for the generation of nonuniform, locally-orthogonal staggered unstructured grids on spheroidal geometries is described. This technique is designed to generate high-quality staggered Voronoi/Delaunay dual meshes appropriate for general circulation modelling on the sphere, including applications to atmospheric simulation, ocean-modelling and numerical weather predication. Using a re...

We investigate a wide range of possible evolutionary histories for the recently discovered Bootes dwarf spheroidal galaxy, a Milky Way satellite. By means of N -body simulations we follow the evolution of possible progenitor galaxies of Bootes for a variety of orbits in the gravitational potential of the Milky Way. The progenitors considered cover the range from dark-matter-free star clusters t...

Isotropic earth models are unable to provide uniform fits to the gross Earth normal mode data set or, in many cases, to regional Loveand Rayleigh-wave data. Anisotropic inversion provides a good fit to the data and indicates that the upper 200 km of the mantle is anisotropic. The nature and magnitude of the required anisotropy, moreover, is similar to that found in body wave studies and in stud...

Tragopogon L. (Cichorioideae, Lactuceae, Scorzonerinae) is an Old World genus with 150 species. Pollen morphology has proved useful in the systematics of some genera and species Asteraceae as well that its The pollen 24 taxa was investigated detail by scanning electron microscopy (SEM). grain type ranged from suboblate, oblate-spheroidal to prolate-spheroidal equatorial view hexagonal, obtuse-h...

[1] Recent modeling results have indicated that, in general, idealized homogeneous spheroidal models of ice crystals and snowflakes cannot consistently describe radar backscattering from snowfall when the radar wavelengths are on the order of the snowflake size. In this paper, we provide empirical evidence supporting this prediction by analyzing collocated airborne radar measurements at 13.4 GH...

From observations of edge-on, late-type galaxies, we present morphological evidence that some nuclear star clusters have experienced in situ star formation. We find three nuclear clusters that, viewed from the edge-on perspective, have both a compact disk-like component and a spheroidal component. In each cluster, the disk components are closely aligned with the major axis of the host galaxy an...

In view of the extensive evidence of tight inter-relationships between spheroidal galaxies (and galactic bulges) with massive black holes hosted at their centers, a consistent model must deal jointly with the evolution of the two components. We describe one such model, which successfully accounts for the local luminosity function of spheroidal galaxies, for their photometric and chemical proper...