Institution
University of Portsmouth
Education•Portsmouth, Portsmouth, United Kingdom•
About: University of Portsmouth is a education organization based out in Portsmouth, Portsmouth, United Kingdom. It is known for research contribution in the topics: Population & Galaxy. The organization has 5452 authors who have published 14256 publications receiving 424346 citations. The organization is also known as: Portsmouth and Gosport School of Science and Art & Portsmouth and Gosport School of Science and the Arts.
Topics: Population, Galaxy, Redshift, Context (language use), Computer science
Papers published on a yearly basis
Papers
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University of Southampton1, University of Queensland2, University of California, Santa Cruz3, Swinburne University of Technology4, University of Pennsylvania5, University of Chicago6, Australian Astronomical Observatory7, University of Sydney8, Australian National University9, University of Portsmouth10, Chinese Academy of Sciences11, Rhodes University12, University College London13, Fermilab14, SLAC National Accelerator Laboratory15, Stanford University16, National Center for Supercomputing Applications17, University of Illinois at Urbana–Champaign18, IFAE19, Spanish National Research Council20, California Institute of Technology21, Steward Health Care System22, Autonomous University of Madrid23, ETH Zurich24, Ohio State University25, Harvard University26, University of São Paulo27, Brandeis University28, State University of Campinas29, Oak Ridge National Laboratory30, University of Michigan31
TL;DR: In this article, the results of a search for rapidly evolving transients in the Dark Energy Survey Supernova Programme were presented, including 72 events, including 37 transients with a spectroscopic redshift from host galaxy spectral features.
Abstract: We present the results of a search for rapidly evolving transients in the Dark Energy Survey Supernova Programme. These events are characterized by fast light-curve evolution (rise to peak in≲10 d and exponential decline in≲30 d after peak).We discovered 72 events, including 37 transients with a spectroscopic redshift from host galaxy spectral features. The 37 events increase the total number of rapid optical transients by more than a factor of two. They are found at a wide range of redshifts (0.05 M > -22.25). The multiband photometry is well fit by a blackbody up to few weeks after peak. The events appear to be hot (T ≈ 10 000-30 000 K) and large (R ≈ 10 - 2 × 10 cm) at peak, and generally expand and cool in time, though some events show evidence for a receding photosphere with roughly constant temperature. Spectra taken around peak are dominated by a blue featureless continuum consistent with hot, optically thick ejecta. We compare our events with a previously suggested physical scenario involving shock breakout in an optically thick wind surrounding a core-collapse supernova, we conclude that current models for such a scenario might need an additional power source to describe the exponential decline. We find that these transients tend to favour star-forming host galaxies, which could be consistent with a core-collapse origin. However, more detailed modelling of the light curves is necessary to determine their physical origin.
130 citations
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TL;DR: Inquiry into the determinants of risk-related sexual behavior is important for the development of interventions to reduce the incidence of new cases of human immunodeficiency virus infection.
Abstract: Inquiry into the determinants of risk-related sexual behavior is important for the development of interventions to reduce the incidence of new cases of human immunodeficiency virus infection. Recent social and behavioral research has revealed much about the individual and social factors influencing risk-taking. Findings from these studies have been important in the development of new educational and community-based interventions for communities at risk in the developed and developing worlds.
129 citations
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University of St Andrews1, École Polytechnique Fédérale de Lausanne2, University of Edinburgh3, Max Planck Society4, Liverpool John Moores University5, University of Nottingham6, University of Sydney7, Cardiff University8, European Southern Observatory9, University of Sussex10, Durham University11, Swinburne University of Technology12, Leiden University13, Carnegie Institution for Science14, University of Portsmouth15, University of Bristol16, Monash University, Clayton campus17, University of Central Lancashire18, Queen Mary University of London19
TL;DR: In this article, the authors discuss the software infrastructure used, and create self-consistent ugrizYJHK photometry for all sources within the Galaxy and Mass Assembly (GAMA) sample.
Abstract: In order to generate credible 0.1–2 μm spectral energy distributions, the Galaxy and Mass Assembly (GAMA) project requires many gigabytes of imaging data from a number of instruments to be reprocessed into a standard format. In this paper, we discuss the software infrastructure we use, and create self-consistent ugrizYJHK photometry for all sources within the GAMA sample. Using UKIDSS and SDSS archive data, we outline the pre-processing necessary to standardize all images to a common zero-point, the steps taken to correct for the seeing bias across the data set and the creation of gigapixel-scale mosaics of the three 4 × 12 deg2 GAMA regions in each filter. From these mosaics, we extract source catalogues for the GAMA regions using elliptical Kron and Petrosian matched apertures. We also calculate Sersic magnitudes for all galaxies within the GAMA sample using sigma, a galaxy component modelling wrapper for galfit 3. We compare the resultant photometry directly and also calculate the r-band galaxy luminosity function for all photometric data sets to highlight the uncertainty introduced by the photometric method. We find that (1) changing the object detection threshold has a minor effect on the best-fitting Schechter parameters of the overall population (M*± 0.055 mag, α± 0.014, ϕ*± 0.0005 h3 Mpc−3); (2) there is an offset between data sets that use Kron or Petrosian photometry, regardless of the filter; (3) the decision to use circular or elliptical apertures causes an offset in M* of 0.20 mag; (4) the best-fitting Schechter parameters from total-magnitude photometric systems (such as SDSS modelmag or Sersic magnitudes) have a steeper faint-end slope than photometric systems based upon Kron or Petrosian measurements; and (5) our Universe’s total luminosity density, when calculated using Kron or Petrosian r-band photometry, is underestimated by at least 15 per cent.
129 citations
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Yale University1, Vanderbilt University2, New Mexico State University3, New York University4, University of Utah5, Harvard University6, Case Western Reserve University7, Swinburne University of Technology8, University of Portsmouth9, Spanish National Research Council10, Autonomous University of Madrid11, Lawrence Berkeley National Laboratory12, Pennsylvania State University13, University of Arizona14, University of California, Berkeley15, Ohio State University16
TL;DR: In this article, the authors report on the small scale (0:5 < r < 40h 1 Mpc) clustering of 78895 massive (M 10 11:3 M ) galaxies at 0:2 < z < 0:4 from the first two years of data from the Baryon Oscillation Spectroscopic Survey (BOSS), to be released as part of SDSS Data Release 9 (DR9).
Abstract: We report on the small scale (0:5 < r < 40h 1 Mpc) clustering of 78895 massive (M 10 11:3 M ) galaxies at 0:2 < z < 0:4 from the first two years of data from the Baryon Oscillation Spectroscopic Survey (BOSS), to be released as part of SDSS Data Release 9 (DR9). We describe the sample selection, basic properties of the galaxies, and caveats for working with the data. We calculate the real- and redshift-space two-point correlation functions of these galaxies, fit these measurements using Halo Occupation Distribution (HOD) modeling within dark matter cosmological simulations, and estimate the errors using mock catalogs. These galaxies lie in massive halos, with a mean halo mass of 5:2 10 13 h 1 M , a large scale bias of 2:0, and a satellite fraction of 12 2%. Thus,
129 citations
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TL;DR: This review focuses on the applications of neural network methods and their development over the last five years and the early problems encountered with neural networks such as overfitting and overtraining are addressed.
129 citations
Authors
Showing all 5624 results
Name | H-index | Papers | Citations |
---|---|---|---|
Robert C. Nichol | 187 | 851 | 162994 |
Gavin Davies | 159 | 2036 | 149835 |
Daniel Thomas | 134 | 846 | 84224 |
Will J. Percival | 129 | 473 | 87752 |
Claudia Maraston | 103 | 362 | 59178 |
I. W. Harry | 98 | 312 | 65338 |
Timothy Clark | 95 | 1137 | 53665 |
Kevin Schawinski | 95 | 376 | 30207 |
Ashley J. Ross | 90 | 248 | 46395 |
Josep Call | 90 | 451 | 34196 |
David A. Wake | 89 | 214 | 46124 |
L. K. Nuttall | 89 | 253 | 54834 |
Stephen Neidle | 89 | 457 | 32417 |
Andrew Lundgren | 88 | 249 | 57347 |
Rita Tojeiro | 87 | 229 | 43140 |