Physics and Astronomy: Recent submissions

Now showing items 481-500 of 520

    • 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 ...

    • Evolution from 4f-electron antiferromagnetic to ferromagnetic order in the CeCu(Ge1-xSnx) alloy series (0≤x≤1) 

      Altayeb, Anas; Sondezi, B. M.; Tchoula Tchokonte, Moise; Strydom, A. M.; Doyle, T. B.; Kaczorowski, D. (American Institute of Physics Inc., 2017)
      We report the evolution from ferromagnetic (FM) to antiferromagnetic (AFM) state in CeCu(Ge1-xSnx) investigated by means of magnetic and heat capacity measurements. X-ray diffraction studies for all compositions indicate ...

    • Revealing the cold dust in low-metallicity environments: I. Photometry analysis of the Dwarf Galaxy Survey with Herschel 

      Remy-Ruyer, A.; Madden, S.C.; Galliano, F.; Hony, S.; Sauvage, M.; Bendo, G.J.; Roussel, H.; Pohlen, M.; Smith, M.W.L.; Galametz, M.; Cormier, D.; Lebouteiller, V.; Wu, R.; Baes, M.; Barlow, M.J.; Boquien, M.; Boselli, A.; Ciesla, L.; De Looze, I.; Karczewski, O.L.; Panuzzo, P.; Spinoglio, L.; Vaccari, M.; Wilson, C.D. (EDP Sciences, 2013)
      Context. We present new photometric data from our Herschel Guaranteed Time Key Programme, the Dwarf Galaxy Survey (DGS), dedicated to the observation of the gas and dust in low-metallicity environments. A total of 48 ...

    • Existence domains of dust-acoustic solitons and supersolitons 

      Maharaj, S.K.; Bharuthram, Ramashwar; Singh, S. V.; Lakhina, G. S. (AIP PublishingAIP Publishing, 2013)
      Using the Sagdeev potential method, the existence of large amplitude dust-acoustic solitons and supersolitons is investigated in a plasma comprising cold negative dust, adiabatic positive dust, Boltzmann electrons, and ...

    • Self-catalytic growth of tin oxide nanowires by chemical vapor deposition process 

      Thabethe, Bongani; Malgas, Gerald; Motaung, David; Malwela, Thomas; Arendse, Christopher (Hindawi, 2013)
      We report on the synthesis of tin oxide (SnO2) nanowires by a chemical vapor deposition (CVD) process. Commercially bought SnO nanopowders were vaporized at 1050∘C for 30 minutes with argon gas continuously passing through ...

    • Hot subdwarf stars in close-up view IV. Helium abundances and the 3He isotopic anomaly of subdwarf B stars 

      Geier, S.; Edelmann, H.; Kilkenny, David; O'Donoghue, D.; Marsh, T.R.; Copperwheat, C. (EDP Sciences, 2013)
      Atmospheric parameters and helium abundances of 44 bright subdwarf B stars have been determined. More than half of our sample consists of newly discovered stars from the Edinburgh Cape survey. We showed that effective ...

    • Herschel-ATLAS/GAMA: What determines the far-infrared properties of radio galaxies? 

      Virdee, J.S.; Hardcastle, M.J.; Jarvis, Matt (OUP, 2013)
      We perform a stacking analysis of Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) data in order to obtain isothermal dust temperatures and rest-frame luminosities at 250 µm (L250), for a well-defined sample ...

    • Herschel-atlas/Gama: a difference between star formation rates in strong-line and weak-line radio galaxies 

      Hardcastle, M.J.; Ching, J.H.Y.; Jarvis, Matt (OUP, 2013)
      We have constructed a sample of radio-loud objects with optical spectroscopy from the Galaxy and Mass Assembly (GAMA) project over the Herschel Astrophysical Terahertz Large Area Survey (Herschel-ATLAS) Phase 1 fields. ...