Motivated by observations of inner halo satellite remnants like the Sgr and ω-Centauri , we develop fully analytical models to study the orbital decay and tidal massloss of satellites on eccentric orbits in an isothermal potential of a host galaxy halo. The orbital decay rate is often severely overestimated if applying the ChandraSekhar’s formula without correcting for (a) the evaporation and t...

Substructures, expected in cold dark matter haloes, have been proposed to explain the anomalous flux ratios in gravitational lenses. About 25% of lenses in the Cosmic Lens All-Sky Survey (CLASS) appear to have luminous satellites within ∼ 5 h kpc of the main lensing galaxies, which are usually at redshift z ∼ 0.2− 1. In this work we use the Millennium Simulation combined with galaxy catalogues ...

Absorption and luminescence excitation spectra of Xe/CF(4) mixtures were studied in the vacuum UV region at high resolution using tunable synchrotron radiation. Pressure-broadened resonance bands and bands associated with dipole-forbidden states of the Xe atom due to collision-induced breakdown of the optical selection rules are reported. The spectra display in addition numerous satellite bands...

In the ectodermal cells of sea urchin blastulae, the microtubules converge and appear to make contact with three distinct cytoplasmic foci or satellites associated with the basal body of the cilium. Beneath the nucleus, which lies in the apical end of the cell, the microtubules are aligned predominantly parallel to the cell's long axis and could thus make contact with the satellites as is direc...

Title of Dissertation: Three-Body Capture of Jupiter’s Irregular Satellites and Resonant History of the Galilean Satellites Catherine M. Philpott, Doctor of Philosophy, 2010 Dissertation directed by: Professor Douglas P. Hamilton Department of Astronomy We examine the capture of small, irregular satellites, which, with their distant, eccentric, and inclined paths, must have originated in helioc...

Recent advances in spacecraft technology allow a large number of smaller and cheaper satellites to fulfill useful Earth monitoring roles. An emerging challenge is to coordinate those satellites to monitor the Earth’s surface and atmosphere. In this paper, we study the satellite assignment problem for a large constellation of Earth observing satellites, where a set of satellites assign themselve...

Directorate, we are developing architectures for commanding and controlling a cluster of cooperating satellites through autonomous software development for the TechSat 21 program (see the “TechSat 21” sidebar starting on page 10). Many space missions require large, monolithic satellites. This often results in costly, complex, failure-prone vehicles whose physical size constraints limit their pe...

We conduct a systematic survey of the regions in which distant satellites can orbit stably around the four giant planets in the Solar system, using orbital integrations of up to 108 yr. We confirm previous results that (i) prograde and retrograde satellites orbiting within the Hill radius rH can survive out to radii of ∼ 0.5rH and ∼ 0.7rH, respectively; (ii) stable orbits do not exist at high e...

On the basis of tidal despinning timescale arguments, Peale showed in 1977 that the majority of irregular satellites (with unknown rotation states) are expected to reside close to their initial (fast) rotation states. Here we investigate the problem of typical rotation states among satellites from a viewpoint of dynamical stability. We explore location of the known planetary satellites on the “...