10,332 research outputs found

    Lyman-alpha Imaging of a Very Luminous z=2.3 Starburst Galaxy with WFPC2

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    We investigate a very luminous Lyman-alpha emitting galaxy, associated with a z=2.3 damped absorption system in the spectrum of the QSO PHL 957. The galaxy was observed with the HST WFPC2, through a narrow filter (F410M) corresponding to rest-frame Lyman -alpha, for 41.2 ksec, with shorter exposures in F555W and F814W. The galaxy is resolved into a close (0.35 arcsec) pair of two components, CFgA and CFgB. The profile of CFgA is consistent with an exponential disk, but CFgB is closer to a bulge galaxy. Fr om the observed colours we estimate rest-frame Lyman-alpha equivalent widths of 151 Angstroms for CFgA and 33 for CFgB. From the F814W and F555W magnitudes we estimate rest-frame blue-band absolute magnitudes of -23.12 for CFgA and -23.24 for CFgB, signi ficantly brighter than local galaxies of the same size. CFgA shows a remarkable 3.9 magnitudes of surface brightness enhancement relative to local spirals, and we speculate that this may be the result of a very luminous starburst, triggered by the merger of the two components. The Lyman-alpha emission could be from a brief phase early in the starburst in which most of these photons can escape. We search for other z=2.3 galaxies with strong Lyman-alpha emission, selecting these by a colour F410M-F555W<-0.2. Eight candidate sources, all fainter than CFgA, are identified. One is a point-source and may be an AGN; the others are irregular a nd of low surface brightness, appearing typical of Lyman break galaxies, but with Lyman-alpha equivalent widths near 100 Angstroms.Comment: 17 pages, Latex, 17 figures. Accepted for publication in MNRA

    Comprehensive Analysis of Arkansas Teacher Salaries: State, Region, and District

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    School funding has been an area of contention in the courts of nearly every state. Many of these court cases have challenged the constitutionality of state funding formulas, arguing the funding system was inadequate or inequitable because poor urban or rural districts often faced a disadvantage in garnering tax dollars for education. Specific to Arkansas, in the 1983 decision Dupree v. Alma School District, the Arkansas Supreme Court declared the state’s funding system was not meeting its constitutional requirements

    The Morphology of 9 Radio-selected Faint Galaxies from deep HST Imaging

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    Using the HST WFPC2 we perform deep I-band imaging of 9 radio-selected (limit 14 microJanskys at 8.5 GHz) faint galaxies from Roche, Lowenthal and Koo (2002). Two are also observed in V. Six of the galaxies have known redshifs of 0.4<z<1.0. Radial intensity profiles indicate that 7 are disk galaxies and 2 are bulge-dominated. Four of the six with redshifts have a high optical surface brightness compared to typical disk galaxies. Two of the 9 galaxies are in close interacting pairs, another two are very asymmetric and three have large, luminous rings resembling the collisional starburst rings in the Cartwheel galaxy. In most of these galaxies the high radio luminosities are probably the result of interaction-triggered starbursts. The mixture of observed morphologies suggests that enhanced radio luminosities often persist for >0.2 Gyr, to a late stage of the interaction. One of these 9 galaxies may be an exception in that it is a large red elliptical and its strong radio emission is more likely to be from an obscured AGN.Comment: 12 pages, latex, 8 figures, accepted for publication in MNRA

    Missing transverse energy significance at CMS

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    Missing transverse energy significance may be used to help distinguish real missing transverse energy due to undetected particles from spurious missing transverse energy due to resolution smearing. We present a description of the missing transverse energy significance variable, and assess its performance in Z→ΌΌ\rightarrow\mu\mu, dijet, and W→eÎœ\rightarrow e\nu events using the CMS 8 TeV dataset.Comment: LHCP Conference 2014. 4 pages, 11 figure

    Design dis-integration Silent, Partial, and Disparate Design

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    Michael Porter’s frameworks for analysing and planning competitive differentiation (Porter 1980, 1985) are established ‘textbook’ tools, widely taught to business students today. As the claim of design’s strategic importance is increasingly heard, we ask where does design fit in established strategy thinking? This paper documents a proposed conceptual model based on Porter’s value chain model for strategic planning. The concept outlined is the result of the first stage of a larger study of design’s potential role at strategic level and the difficulties faced by organisations in exploiting design strategically. This exploratory phase comprised a review of literature on design management and models of strategy, followed by nineteen interviews with senior design professionals. These then informed a novel revision of the value chain diagram reflecting the strategic role of design, and the identification of three key phenomena concerning design integration (silent design, partial design and disparate design). These phenomena are also represented in modified versions of the value chain. This overall project follows a research approach based on the design research method and on procedural action research, and aims to develop a tool or method to help organisations increase design integration. This project is ongoing, and the results will be published separately. Keywords: Strategic; value chain; silent; partial; disparate; integrated</p
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