Research Articles (Physics): Recent submissions

Now showing items 461-480 of 520

    • An overview of the Dwarf Galaxy Survey 

      Remy-Ruyer, A.; Galametz, M.; Vaccari, Mattia; Madden, S.C. (The Astronomical Society of the Pacific, 2013)
      The Dwarf Galaxy Survey (DGS) program is studying low-metallicity galax- ies using 230h of far-infrared (FIR) and submillimetre (submm) photometric and spectroscopic observations of the Herschel Space Observatory and ...

    • Comparative study: the effect of annealing conditions on the properties of P3HT:PCBM blends 

      Motaung, David E.; Malgas, Gerald; Nkosi, Steven S.; Mhlongo, Gugu H.; Mwakikunga, Bonex W.; Malwela, Thomas; Arendse, Christopher; Muller, Theophillus F. G.; Cummings, Franscious R. (Springer Verlag, 2013)
      This paper presents a detailed study on the role of various annealing treatments on organic poly(3-hexylthiophene) and [6]-phenyl-C61-butyric acid methyl ester blends under different experimental conditions. A combination ...

    • Bringing together knowledge and capabilities: a case study of engineering graduates 

      Case, Jennifer M.; Marshall, Delia (Springer Verlag, 2016)
      In contemporary times there is a renewed focus on the purposes of university education in science or engineering, especially inemerging economycontexts like South Africa where the massification of higher education is in ...

    • Calibrating photometric redshifts with intensity mapping observations 

      Alonso, David; Ferreira, Pedro G.; Jarvis, Matt; Moodley, Kavilan (American Physical Society, 2017)
      Imaging surveys of galaxies will have a high number density and angular resolution yet a poor redshift precision. Intensity maps of neutral hydrogen (HI) will have accurate redshift resolution yet will not resolve ...

    • Annealing effect of hybrid solar cells based on poly (3-hexylthiophene) and zinc-oxide nanostructures 

      Motaung, David; Malgas, Gerald; Ray, Suprakas S.; Arendse, Christopher (Elsevier, 2013)
      The structural growth and optical and photovoltaic properties of the organic–inorganic hybrid structures of zinc oxide (ZnO)-nanorods/poly-3-hexylthiophene (P3HT) and two variations of organic polymer blends of ZnO/ ...

    • Inelastic scattering of 9Li and excitation mechanism of its first excited state 

      Al Falou, H.; Kanungo, R.; Orce, J.N. (Elsevier, 2013)
      The first measurement of inelastic scattering of 9Li from deuterons at the ISAC facility is reported. The measured angular distribution for the first excited state confirms the nature of excitation to be an E2 transition. ...

    • Investigations on the characterization of ion implanted hexagonal boran nitride 

      Aradi, E.; Naidoo, S.R.; Erasmus, R.M.; Julies, B.; Derry, T.E. (Elsevier, 2013)
      The effect of ion implantation on hexagonal boron nitride (h-BN) is studied herein. We use boron as an ion of choice to introduce radiation damage into h-BN, at fluences ranging from 1 x 10 14–1 x 10 16 ions/cm2 and ...

    • Periodic variations in the O-C diagrams of five pulsation frequencies of the DB white dwarf EC 20058-5234 

      Dalessio, J.; Sullivan, D. J.; Kilkenny, David; Provencal, J. L.; Shipman, H. L.; Sullivan, T.; Fraga, L.; Sefako, R. (American Physical Society, 2013)
      Variations in the pulsation arrival time of five independent pulsation frequencies of the DB white dwarf EC 20058−5234 individually imitate the effects of reflex motion induced by a planet or companion but are inconsistent ...

    • Probing reionization with LOFAR (Low Frequency Array) using 21-cm redshift space distortions 

      Jensen, Hannes; Datta, Kanan K.; Santos, Mario G.; Mellema, Garrelt; Chapman, Emma; Abdalla, Filipe B.; Iliev, Ilian T.; Mao, Yi; Shapiro, Paul R.; Zaroubi, Saleem; Bernardi, Gianni; Brentjens, M. A.; de Bruyn, A. G.; Ciardi, B.; Harker, G. J. A.; Jelić, V.; Kazemi, S.; Koopmans, L. V. E.; Labropoulos, P.; Martinez, O.; Offringa, A. R.; Pandey, V. N.; Schaye, J.; Thomas, R. M.; Veligatla, V.; Vedantham, H.; Yatawatta, S. (Oxford University Press, 2013)
      One of the most promising ways to study the epoch of reionization (EoR) is through radio observations of the redshifted 21-cm line emission from neutral hydrogen. These observations are complicated by the fact that the ...

    • Probing the bias of radio sources at high redshift 

      Passmoor, S.; Cress, Catherine; Faltenbacher, Andreas; Johnston, Russell; Smith, Mathew; Ratsimbazafy, Ando; Hoyle, Ben (Oxford University Press, 2013)
      The relationship between the clustering of dark matter and that of luminous matter is often described using the bias parameter. Here, we provide a new method to probe the bias of intermediate-to-high-redshift radio ...

    • Properties of Type Ia supernovae inside rich galaxy clusters 

      Xavier, Henrique S.; Gupta, Ravi R.; Smith, Mathew; Sako, Masao; D’Andrea, Chris B.; Frieman, Joshua A.; Galbany, Lluis; Garnavich, Peter M.; Marriner, John; Nichol, Robert C.; Olmstead, Matthew D.; Schneider, Donald P. (Oxford University Press, 2013)
      We used the Gaussian Mixture Brightest Cluster Galaxy catalogue and Sloan Digital Sky Survey-II supernovae data with redshifts measured by the Baryon Oscillation Spectroscopic Survey to identify 48 Type Ia supernovae ...

    • Radio-loud active calactic nucleus: is there a link between luminosity and cluster environment? 

      Ineson, J.; Croston, J. H.; Jarvis, Matt; Hardcastle, M.J.; Evans, D. A.; Kraft, R. P. (American Physical Society, 2013)
      We present here the first results from the Chandra ERA (Environments of Radio-loud AGN) Large Project, characterizing the cluster environments of a sample of 26 radio-loud active galactic nuclei (AGNs) at z ∼ 0.5 that ...

    • Revised SWIRE photometric redshifts 

      Rowan-Robinson, Michael; Gonzalez-Solares, Eduardo A.; Vaccari, Mattia; Marchetti, L. (Oxford University Press, 2013)
      We have revised the Spitzer Wide-Area Infrared Extragalactic survey (SWIRE) Photometric Redshift Catalogue to take account of new optical photometry in several of the SWIRE areas, and incorporating Two Micron All Sky ...

    • Sample variance, source clustering and their influence on the counts of faint radio sources 

      Heywood, Ian; Jarvis, Matt; Condon, James J. (Oxford University Press, 2013)
      The shape of the curves defined by the counts of radio sources per unit area as a function of their flux density was one of the earliest cosmological probes. Radio source counts continue to be an area of astrophysical ...

    • SN Ia host galaxy properties from Sloan Digital Sky Survey-II spectroscopy 

      Johansson, Jonas; Thomas, Daniel; Smith, Mathew; Pforr, Janine; Maraston, Claudia; Nichol, Robert C.; Lampeitl, Hubert; Beifiori, Alessandra; Gupta, Ravi R.; Schneider, Donald P. (Oxford University Press, 2013)
      We study the stellar populations of Type Ia supernova (SN Ia) host galaxies using Sloan Digital Sky Survey (SDSS)-II spectroscopy. The main focus is on the relationships of SN Ia properties with stellar velocity dispersion ...

    • Stacked reverberation mapping 

      Fine, Stephen; Shanks, T.; Green, P.; Kelly, B.; Croom, S. M.; Webster, R. L.; Berger, E.; Chornock, R.; Burgett, W. S.; Chambers, K. C.; Kaiser, N.; Price, P. A. (Oxford University Press, 2013)
      Over the past 20 years reverberation mapping has proved one of the most successful techniques for studying the local (<1 pc) environment of supermassive black holes that drive active galactic nuclei. Key successes of ...

    • Testing gravity using large-scale redshift-space distortions 

      Raccanelli, Alvise; Bertacca, Daniele; Pietrobon, Davide; Schmidt, Fabian; Samushia, Lado; Bartolo, Nicola; Doré, Olivier; Matarrese, Sabino; Percival, Will J. (Oxford University Press, 2013)
      We use luminous red galaxies from the Sloan Digital Sky Survey (SDSS) II to test the cosmological structure growth in two alternatives to the standard cold dark matter ( CDM)+general relativity (GR) cosmological model. ...

    • Shell-model studies of the astrophysical rp reaction 29P(p, y)30 S 

      Richter, W. A.; Brown, B. Alex (American Physical Society, 2013)
      We present results for levels in 30S (the mirror nucleus of 30Si) that are used for the 29P(p,γ ) rp reaction rate calculations. The resonance energies used in the reaction rate calculations are based on recent ...

    • Testing homegeneity with Galaxy Star formation histories 

      Hoyle, Ben; Jimenez, Raul; Maartens, Roy; Heavens, Alan; Clarkson, Chris; Tojeiro, Rita (IOP Publishing, 2013)
      Observationally confirming spatial homogeneity on sufficiently large cosmological scales is of importance to test one of the underpinning assumptions of cosmology, and is also imperative for correctly interpreting dark ...

    • The complex physics of dusty star-forming galaxies at high redshifts as revealed by Herschel and Spitzer 

      Lo Faro, Barbara; Franceschini, Alberto; Vaccari, M.; Silva, L.; Rodighiero, G.; Berta, S.; Bock, J.; Burgarella, D.; Buat, V.; Cava, A.; Clements, D.L.; Cooray, Asantha; Farrah, D.; Feltre, Anna; Gonzalez-Solares, Eduardo A.; Hurley, P.; Lutz, D.; Magdis, G.; Magnelli, B.; Marchetti, L.; Oliver, S.J.; Page, Matthew J.; Popesso, P.; Pozzi, F.; Rigopoulou, D.; Rowan-Robinson, M.; Roseboom, I.G.; Scott, Douglas; Smith, A.J.; Symeonidis, Myrto; Wang, L.; Wuyts, S. (IOP Publishing, 2013)
      We combine far-infrared photometry from Herschel (PEP/HerMES) with deep mid-infrared spectroscopy from Spitzer to investigate the nature and the mass assembly history of a sample of 31 luminous and ultraluminous infrared ...