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, Poison control, Fuzzy logic
Papers published on a yearly basis
Papers
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Queen's University Belfast1, Max Planck Society2, California Institute of Technology3, University College Dublin4, University of Southampton5, University of Hawaii6, University of Copenhagen7, Weizmann Institute of Science8, University of Warwick9, University of Edinburgh10, Millennium Institute11, Andrés Bello National University12, European Southern Observatory13, Liverpool John Moores University14, Stockholm University15, Space Science Institute16, Pontifical Catholic University of Chile17, INAF18, University of Padua19, Radboud University Nijmegen20, Netherlands Institute for Space Research21, Spanish National Research Council22, Centre national de la recherche scientifique23, University of Chile24, University of Portsmouth25, University of Pittsburgh26, Instituto Superior Técnico27, University of Warsaw28, University of Turku29, University of Iceland30, Valparaiso University31, University of Cambridge32, Lancaster University33, Humboldt University of Berlin34, Heidelberg University35, Heidelberg Institute for Theoretical Studies36, Institut d'Astrophysique de Paris37, University of Oxford38, University of Catania39, Johns Hopkins University40, Space Telescope Science Institute41, Inter-University Centre for Astronomy and Astrophysics42, Australian National University43, University of New South Wales44, Harvard University45, University of the Free State46, Northwestern University47, University of Minnesota48
TL;DR: Observations and physical modelling of a rapidly fading electromagnetic transient in the galaxy NGC 4993, which is spatially coincident with GW170817, indicate that neutron-star mergers produce gravitational waves and radioactively powered kilonovae, and are a nucleosynthetic source of the r-process elements.
Abstract: Gravitational waves were discovered with the detection of binary black-hole mergers and they should also be detectable from lower-mass neutron-star mergers. These are predicted to eject material rich in heavy radioactive isotopes that can power an electromagnetic signal. This signal is luminous at optical and infrared wavelengths and is called a kilonova. The gravitational-wave source GW170817 arose from a binary neutron-star merger in the nearby Universe with a relatively well confined sky position and distance estimate. Here we report observations and physical modelling of a rapidly fading electromagnetic transient in the galaxy NGC 4993, which is spatially coincident with GW170817 and with a weak, short γ-ray burst. The transient has physical parameters that broadly match the theoretical predictions of blue kilonovae from neutron-star mergers. The emitted electromagnetic radiation can be explained with an ejected mass of 0.04 ± 0.01 solar masses, with an opacity of less than 0.5 square centimetres per gram, at a velocity of 0.2 ± 0.1 times light speed. The power source is constrained to have a power-law slope of -1.2 ± 0.3, consistent with radioactive powering from r-process nuclides. (The r-process is a series of neutron capture reactions that synthesise many of the elements heavier than iron.) We identify line features in the spectra that are consistent with light r-process elements (atomic masses of 90-140). As it fades, the transient rapidly becomes red, and a higher-opacity, lanthanide-rich ejecta component may contribute to the emission. This indicates that neutron-star mergers produce gravitational waves and radioactively powered kilonovae, and are a nucleosynthetic source of the r-process elements.
695 citations
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TL;DR: In this paper, the authors identify systematic variations in hafnium and oxygen isotopes in zircons of different ages that reveal the relative proportions of reworked crust and of new crust through time, and a marked decrease in the rate of crustal growth at ~3 billion years ago may be linked to the onset of subduction-driven plate tectonics.
Abstract: Models for the growth of continental crust rely on knowing the balance between the generation of new crust and the reworking of old crust throughout Earth’s history. The oxygen isotopic composition of zircons, for which uranium-lead and hafnium isotopic data provide age constraints, is a key archive of crustal reworking. We identified systematic variations in hafnium and oxygen isotopes in zircons of different ages that reveal the relative proportions of reworked crust and of new crust through time. Growth of continental crust appears to have been a continuous process, albeit at variable rates. A marked decrease in the rate of crustal growth at ~3 billion years ago may be linked to the onset of subduction-driven plate tectonics.
695 citations
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TL;DR: Four graphical typologies are used to outline the questions that multilevel models can address and the paper illustrates their potential by drawing on published examples in a number of different research areas.
685 citations
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TL;DR: It is shown that density perturbations in hybrid inflation models of the new type can be very large on the scale corresponding to the phase transition, which could lead to a copious production of black holes in these models.
Abstract: We investigate the recently proposed hybrid inflation models with two stages of inflation. We show that quantum fluctuations at the time corresponding to the phase transition between the two inflationary stages can trigger the formation of a large number of inflating topological defects. In order to study density perturbations in these models we further develop a method to calculate density perturbations in a system of two scalar fields. We show that density perturbations in hybrid inflation models of the new type can be very large on the scale corresponding to the phase transition. The resulting density inhomogeneties lead to a copious production of black holes. This could be an argument against hybrid inflation models with two stages of inflation. However, we find a class of models where this problem can be easily avoided. The number of black holes produced in these models can be made extremely small, but in general it could be sufficiently large to have important cosmological and astrophysical implications. In particular, for certain values of parameters these black holes may constitute the dark matter in the Universe. It is also possible to have hybrid models with two stages of inflation where the black hole production is not suppressed, but where the typical masses of the black holes are very small. Such models lead to a completely different thermal history of the Universe, where postinflationary reheating occurs via black hole evaporation.
684 citations
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TL;DR: The structural basis of talin's unique ability to activate integrins is revealed, an interaction that could aid in the design of therapeutics to block integrin activation is identified, and engineering of cells with defects in the activation of multiple classes of integrin is enabled.
674 citations
Authors
Showing all 5624 results
Name | H-index | Papers | Citations |
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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 |