NICMOS Observations of the Pre-Main-Sequence Planetary Debris System HD 98800

Spectral energy distributions (SEDs) from 0.4 to 4.7 microns are presented for the two principal stellar components of HD~98800, A and B. The third major component, an extensive planetary debris system (PDS), emits > 20% of the luminosity of star B in a blackbody SED at 164 +/- 5K extending from mid-IR to millimeter-wavelengths. At 0.95 microns a preliminary upper limit of < 0.06 is obtained for the ratio of reflected light to the total from star B. This result limits the albedo of the PDS to < 0.3. Values are presented for the temperature, luminosity, and radius of each major systemic component. Remarkable similarities are found between the PDS and the interplanetary debris system around the Sun as it could have appeared a few million years after its formation.Comment: LaTeX, 9 pages with 1 encapsulated postscript figure and one specially formatted Table which is rendered as a postscript file and included as a figure. Accepted for publication in Astrophysical Journal Letter

Dust in the wind: Crystalline silicates, corundum and periclase in PG 2112+059

We have determined the mineralogical composition of dust in the Broad Absorption Line (BAL) quasar PG 2112+059 using mid-infrared spectroscopy obtained with the Spitzer Space Telescope. From spectral fitting of the solid state features, we find evidence for Mg-rich amorphous silicates with olivine stoichiometry, as well as the first detection of corundum (Al_2O_3) and periclase (MgO) in quasars. This mixed composition provides the first direct evidence for a clumpy density structure of the grain forming region. The silicates in total encompass 56.5% of the identified dust mass, while corundum takes up 38 wt.%. Depending on the choice of continuum, a range of mass fractions is observed for periclase ranging from 2.7% in the most conservative case to 9% in a less constrained continuum. In addition, we identify a feature at 11.2 micron as the crystalline silicate forsterite, with only a minor contribution from polycyclic aromatic hydrocarbons. The 5% crystalline silicate fraction requires high temperatures such as those found in the immediate quasar environment in order to counteract rapid destruction from cosmic rays.Comment: 2 figure

A Large Mass of H2 in the Brightest Cluster Galaxy in Zwicky 3146

We present the Spitzer/IRS mid-infrared spectrum of the infrared-luminous (L_{IR}=4e11 L_sun) brightest cluster galaxy (BCG) in the X-ray-luminous cluster Z3146 (z=0.29). The spectrum shows strong aromatic emission features, indicating that the dominant source of the infrared luminosity is star formation. The most striking feature of the spectrum, however, is the exceptionally strong molecular hydrogen (H2) emission lines, which seem to be shock-excited. The line luminosities and inferred warm H2 gas mass (~1e10 M_sun) are 6 times larger than those of NGC 6240, the most H2-luminous galaxy at z <~ 0.1. Together with the large amount of cold H2 detected previously (~1e11 M_sun), this indicates that the Z3146 BCG contains disproportionately large amounts of both warm and cold H2 gas for its infrared luminosity, which may be related to the intracluster gas cooling process in the cluster core.Comment: 13 pages, 3 figures, 1 table; Accepted for publication in ApJ

Entanglement Sharing and Decoherence in the Spin-Bath

The monogamous nature of entanglement has been illustrated by the derivation of entanglement sharing inequalities - bounds on the amount of entanglement that can be shared amongst the various parts of a multipartite system. Motivated by recent studies of decoherence, we demonstrate an interesting manifestation of this phenomena that arises in system-environment models where there exists interactions between the modes or subsystems of the environment. We investigate this phenomena in the spin-bath environment, constructing an entanglement sharing inequality bounding the entanglement between a central spin and the environment in terms of the pairwise entanglement between individual bath spins. The relation of this result to decoherence will be illustrated using simplified system-bath models of decoherence.Comment: 5 pages, 1 figure v2: 6 pages 2 figures, additional example and reference

Lean towards learning: connecting Lean Thinking and human resource management in UK higher education

From its origins in the automotive industry, Lean Thinking is increasingly being seen as a solution to problems of efficiency and quality in other industries and sectors. In recent years attempts have been made to transfer Lean principles and practice to the higher education sector with indications of mixed consequences and debate over its suitability. This paper contributes to the debate by drawing evidence from thirty-four interviews conducted across two UK universities that have implemented Lean in some of their activities and we pay particular attention to the role of the HR function in facilitating its introduction. The findings suggest there are problems in understanding, communicating and transferring Lean Thinking in the higher education context; that, despite HR systems being vital facets of Lean, HR professionals are excluded from participation; and that as a consequence the depth and breadth of Lean application in the two institutions is very limited