Now showing items 481-500 of 520

    • The COS-Halos survey: Rationale, design and a census of circumgalactic neutral hydrogen 

      Tumlinson, Jason; Thom, Christopher; Dave, Romeel; Werk, Jessica K.; Prochaska, J. Xavier; Tripp, Todd M.; Katz, Neal; Oppenheimer, Benjamin D.; Meiring, Joseph D.; Ford, Amanda Brady; O'Meara, John M.; Peeples, Molly S.; Sembach, Kenneth R.; Weinberg, David H. (IOP Publishing, 2013)
      We present the design and methods of the COS-Halos survey, a systematic investigation of the gaseous halos of 44 z = 0.15–0.35 galaxies using background QSOs observed with the Cosmic Origins Spectrograph aboard the Hubble ...
    • The cosmic evolution of the IMF under the Jeans conjecture with implications for massive galaxies 

      Narayanan, Desika; Dave, Romeel (Oxford University Press, 2013)
      We examine the cosmic evolution of a stellar initial mass function (IMF) in galaxies that varies with the Jeans mass in the interstellar medium, paying particular attention to the K-band stellar mass-to-light ratio (M/LK) ...
    • The Edinburgh-Cape Blue Object Survey - III. Zone 2; galactic latitudes -30? > b > -40? 

      Kilkenny, David; Koen, Chris; Hambly, N.; MacGillivray, H.; Stobie, R. S.; O’Donoghue, D. (Oxford University Press, 2013)
      The Edinburgh–Cape Blue Object Survey seeks to identify point sources with an ultraviolet excess. Results for zone 2 of the survey are presented here, covering that part of the South Galactic Cap between 30◦ and 40◦ from ...
    • The faint source population at 15.7 GHz - I. The radio properties 

      Whittam, I.; Riley, J.; Jarvis, Matt; Green, D.A.; Prandoni, I.; Guglielmino, G.; Morganti, R.; Röttgering, H. J. A.; Garrett, M. A. (Oxford University Press, 2013)
      We have studied a sample of 296 faint (>0.5 mJy) radio sources selected from an area of the Tenth Cambridge (10C) survey at 15.7 GHz in the Lockman Hole. By matching this catalogue to several lower frequency surveys (e.g. ...
    • The high-ion content and kinematics of low-redshift lyman limit systems 

      Fox, Andrew J.; Lehner, Nicholas; Dave, Romeel; Tumlinson, Jason; Howk, J. Christopher; Tripp, Todd M.; Prochaska, J. Xavier; O'Meara, John M.; Werk, Jessica K.; Bordoloi, Rongmon; Katz, Neal; Oppenheimer, Benjamin D. (The American Astronomical Society, 2013)
      We study the high-ion content and kinematics of the circumgalactic medium around low-redshift galaxies using a sample of 23 Lyman limit systems (LLSs) at 0.08 < z < 0.93 observed with the Cosmic Origins Spectrograph on ...
    • The host haloes of O I absorbers in the reionization epoch 

      Finlator, Kristian; Muñoz, Joseph A.; Dave, Romeel; Oppenheimer, B. D.; Peng Oh, S.; Özel, Feryal (Oxford University Press, 2013)
      We use a radiation hydrodynamic simulation of the hydrogen reionization epoch to study OI absorbers at z ∼ 6. The intergalactic medium (IGM) is reionized before it is enriched; hence, OI absorption originates within dark ...
    • Mind the gap: Science and engineering education at the secondary–tertiary interface 

      Case, Jenni; Marshall, Delia; Grayson, Diane (Academy of Science of South Africa, 2013)
      In the South African higher education sector, there is increasing concern about the poor retention and throughput rates of undergraduate students. There is also concern that the participation rates in higher education, ...
    • The neutral hydrogen content of galaxies in cosmological hydrodynamic simulations 

      Dave, Romeel; Katz, Neal; Oppenheimer, Benjamin D.; Kollmeier, Juna A.; Weinberg, David H. (Oxford University Press, 2013)
      We examine the global HI properties of galaxies in quarter billion particle cosmological simulations using GADGET-2, focusing on howgalactic outflows impactHI content.We consider four outflow models, including a new one ...
    • The ongoing pursuit of R Coronae Borealis stars: the ASAS-3 survey strikes again 

      Tisserand, P.; Clayton, G.; Kilkenny, David; Welch, D. L.; Wyrzykowsk, L.; Pilecki, B. (EDP Sciences, 2013)
      CONTEXT: R Coronae Borealis stars( RCBs) are rare, hydrogen-deficient, carbon rich super giant variable stars that are likely the evolved merger products of pairs of CO and He white dwarfs. Only 55 RCB stars have been found ...
    • Using a disciplinary discourse lens to explore how representations afford meaning making in a typical wave physics course 

      Enghag, Margareta; Forsman, Jonas; Linder, Cedric; MacKinnon, Allan; Moons, Ellen (Springer Verlag, 2013)
      We carried out a case study in a wave physics course at a Swedish university in order to investigate the relations between the representations used in the lessons and the experience of meaning making in interview–discussions. ...
    • The preferentially magnified active nucleus in IRAS F10214+4724 - III. VLBI observations of the radio core 

      Deane, Roger P.; Rawlings, S.; Jarvis, Matt; Garrett, M. A.; Heywood, Ian; Klöckner, H. R.; Marshall, P. J.; McKean, J. P. (Oxford University Press, 2013)
      We report 1.7GHz very long baseline interferometry (VLBI) observations of IRAS F10214+4724, a lensed z = 2.3 obscured quasar with prodigious star formation. We detect what we argue to be the obscured active nucleus with ...
    • The Q/U imaging experiment instrument 

      Biscoff, C.; Brizius, A.; Zwart, J.; Buder, I.; Chinone, Y.; Cleary, K.; Dumoulin, R.N.; Kusaka, A.; Monsalve, R.; Naess, S.K.; Newburgh, L.B.; Nixon, G.; Reeves, R.; Smith, K.M.; Vanderlinde, K.; Wehus, I.K.; Bogdan, M.; Bustos, R.; Church, S.E.; Davis, Robert; Dickenson, C.; Eriksen, H.K.; Gaier, T.; Gundersen, J.O.; Hasegawa, M.; Hazumi, M.; Holler, C.; Huffenberger, K.M.; Imbriale, W.A.; Ishidoshiro, K.; Jones, M.E.; Kangaslahti, P.; Kapner, D.J.; Lawrence, C.R.; Leitch, E.M.; Limon, M.; McMahon, J.J.; Miller, A.D.; Nagai, M.; Nguyen, H.; Pearson, T.J.; Piccirillo, L.; Radford, S.J.E.; Readhead, A.C.S.; Richards, J.L.; Samtleben, D.; Seiffert, M.; Shepherd, M.C.; Staggs, S.T.; Tajima, O.; Thompson, K.L.; Williamson, R.; Winstein, B.; Wollack, E.J. (The American Astronomical Society, 2013)
      The Q/U Imaging ExperimenT (QUIET) is designed to measure polarization in the cosmic microwave background, targeting the imprint of inflationary gravitational waves at large angular scales(∼1◦). Between 2008 October and ...
    • The roles of star formation and AGN activity of IRS sources in the HerMES fields 

      Feltre, Anna; Hatziminaoglou, Evanthia; Vaccari, Mattia; Hernán-Caballero, Antonio; Fritz, Jacopo; Franceschini, Alberto; Bock, J.; Cooray, Asantha; Farrah, Duncan; Gonzalez-Solares, Eduardo A.; Ibar, Edo; Isaak, Kate G.; Lo Faro, Barbara; Marchetti, L.; Oliver, Seb J.; Page, Matthew J.; Rigopoulou, Dimitra; Roseboom, Isaac G.; Symeonidis, Myrto (Oxford University Press, 2013)
      In this work we explore the impact of the presence of an active galactic nucleus (AGN) on the mid- and far-infrared (IR) properties of galaxies as well as the effects of simultaneous AGN and starburst activity in these ...
    • The slow flow model of dust eflux in local star-forming galaxies 

      Zahid, H.; Torrey, Paul; Dave, Romeel; Geller, Margaret; Kudritzki, Rolf; Kewley, Lisa J. (Oxford University Press, 2013)
      We develop a dust efflux model of radiation pressure acting on dust grains which successfully reproduces the relation between stellar mass, dust opacity and star forma- tion rate observed in local star-forming galaxies. ...
    • Students' ontological security and agency in science education - an example from reasoning about the use of gene technology 

      Lindahl, Mats Gunnar; Linder, Cedric (Taylor & Francis, 2013)
      This paper reports on a study of how students' reasoning about socioscientific issues is framed by three dynamics: societal structures, agency and how trust and security issues are handled. Examples from gene technology ...
    • The VISTA Deep Extragalactic Observations (VIDEO) survey 

      Jarvis, Matt; Bonfield, David G.; Bruce, V.A.; Zwart, J.; Geach, J.E.; McAlpine, K.; McLure, R.J.; Gonzalez-Solares, Eduardo A.; Irwin, M.; Lewis, J.; Kupcu Yoldas, A.; Andreon, S.; Cross, N.J.G.; Emerson, J.P.; Dalton, G.; Dunlop, J.S.; Hodgkin, S. T.; Le Fevre, O.; Karouzos, M.; Meisenheimer, K.; Oliver, S.; Rawlings, S.; Simpson, Chris; Smail, I.; Smith, Daniel J.B.; Sullivan, M.; Sutherland, W.; White, S.V. (Oxford University Press, 2013)
      In this paper we describe the first data release of the the Visible and Infrared Survey Telescope for Astronomy (VISTA) Deep Extragalactic Observations (VIDEO) survey. VIDEO is a 12 degree2 survey in the near-infrared ...
    • Theoretical evolution of optical strong lines across cosmic time 

      Kewley, Lisa J.; Dopita, Michael A.; Dave, Romeel; Leitherer, Claus; Yuan, Tiantian; Allen, Mark; Groves, Brent; Sutherland, Ralph (The American Astronomical Society, 2013)
      We use the chemical evolution predictions of cosmological hydrodynamic simulations with our latest theoretical stellar population synthesis, photoionization, and shock models to predict the strong line evolution of ...
    • A framework for assessing the performance of pulsar search pipelines 

      van Heerden, E.; Karastergiou, A.; Roberts, J. (Oxford Unviersity Press, 2016)
      In this paper, we present a framework for assessing the effect of non-stationary Gaussian noise and radio frequency interference (RFI) on the signal to noise ratio, the number of false positives detected per true positive ...
    • Gaia Data Release 1. Open cluster astrometry: performance, limitations, and future prospects 

      van Leeuwen, F.; Vallenari, A.; Vaccari, M. (EDP Sciences, 2017)
      CONTEXT: The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are ...
    • Mufasa: The assembly of the red sequence 

      Dave, Romeel; Rafieferantso, Mika H.; Thompson, Robert J. (Oxford University Press, 2017)
      We examine the growth and evolution of quenched galaxies in the Mufasa cosmo- logical hydrodynamic simulations that include an evolving halo mass-based quench- ing prescription, with galaxy colours computed accounting ...