1,348 research outputs found

    Searching High Redshift Large-Scale Structures: Photometry of Four Fields Around Quasar Pairs at z~1

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    We have studied the photometric properties of four fields around the high-redshift quasar pairs QP1310+0007, QP1355-0032, QP0110-0219, and QP0114-3140 at z ~ 1 with the aim of identifying large-scale structures- galaxy clusters or groups- around them. This sample was observed with GMOS in Gemini North and South telescopes in the g', r', i', and z' bands, and our photometry is complete to a limiting magnitude of i' ~ 24 mag (corresponding to ~ M*_i' + 2 at the redshift of the pairs). Our analysis reveals that QP0110-0219 shows very strong and QP1310+0007 and QP1355-0032 show some evidence for the presence of rich galaxy clusters in direct vicinity of the pairs. On the other hand, QP0114-3140 could be an isolated pair in a poor environment. This work suggest that z ~ 1 quasar pairs are excellent tracers of high density environments and this same technique may be useful to find clusters at higher redshifts.Comment: 29 pages, 7 figures, ApJ accepted. Added one figure and 3 references. Some paragraphs was rewritten in sections 1, 3, 5, and 6, as suggested by refere

    3D freeform surfaces from planar sketches using neural networks

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    A novel intelligent approach into 3D freeform surface reconstruction from planar sketches is proposed. A multilayer perceptron (MLP) neural network is employed to induce 3D freeform surfaces from planar freehand curves. Planar curves were used to represent the boundaries of a freeform surface patch. The curves were varied iteratively and sampled to produce training data to train and test the neural network. The obtained results demonstrate that the network successfully learned the inverse-projection map and correctly inferred the respective surfaces from fresh curves

    The ESO Key-Programme ``A Homogeneous Bright QSO Survey'' - I The Methods and the ``Deep'' Fields

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    This is the first paper in a series aimed at defining a statistically significant sample of QSOs in the range 15<B<18.75 15 < B < 18.75 and 0.3<z<2.2 0.3 < z < 2.2. The selection is carried out using direct plates obtained at the ESO and UK Schmidt Telescopes, scanned with the COSMOS facility and searched for objects with an ultraviolet excess. Follow-up spectroscopy, carried out at ESO La Silla, is used to classify each candidate. In this initial paper, we describe the scientific objectives of the survey; the selection and observing techniques used. We present the first sample of 285 QSOs (MB<−23M_B < -23) in a 153 deg2^2 area, covered by the six ``deep'' fields, intended to obtain significant statistics down B≃18.75B \simeq 18.75 with unprecedented photometric accuracy. From this database, QSO counts are determined in the magnitude range 17<B<18.75 17 < B < 18.75.Comment: 21 pages uuencoded compressed postscript, to appear in Astronomy and Astrophysics Supplements, 199

    Supporting public involvement in interview and other panels: a systematic review.

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    BACKGROUND: Members of the public are increasingly being invited to become members of a variety of different panels and boards. OBJECTIVE: This study aimed to systematically search the literature to identify studies relating to support or training provided to members of the public who are asked to be members of an interview panel. SEARCH STRATEGY: A systematic search for published and unpublished studies was carried out from June to September 2015. The search methods included electronic database searching, reference list screening, citation searching and scrutinizing online sources. INCLUSION CRITERIA: We included studies of any design including published and unpublished documents which outlined preparation or guidance relating to public participants who were members of interview panels or representatives on other types of panels or committees. DATA SYNTHESIS: Results were synthesised via narrative methods. MAIN RESULTS: Thirty-six documents were included in the review. Scrutiny of this literature highlighted ten areas which require consideration when including members of the public on interview panels: financial resources; clarity of role; role in the interview process; role in evaluation; training; orientation/induction; information needs; terminology; support; and other public representative needs such as timing, accessibility and support with information technology. DISCUSSION AND CONCLUSIONS: The results of the review emphasize a range of elements that need to be fully considered when planning the involvement of public participants on interview panels. It highlights potential issues relating to the degree of involvement of public representatives in evaluating/grading decisions and the need for preparation and on-going support
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