Browsing by Author "Liebenberg, I."

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    Revival of the magnetar PSR J1622–4950 : observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR
    (American Astronomical Society, 2018) Camilo, F.; Serylak, M.; Buchner, S.; Merryfield, M.; Kaspi, V. M.; Archibald, R. F.; Bailes, M.; Jameson, A.; Van Straten, W.; Sarkissian, J.; Reynolds, J. E.; Johnston, S.; Hobbs, G.; Abbott, T. D.; Adam, R. M.; Adams, G. B.; Alberts, T.; Andreas, R.; Asad, K. M. B.; Baker, D. E.; Baloyi, T.; Bauermeister, E. F.; Baxana, T.; Bennett, T. G. H.; Bernardi, G.; Booisen, D.; Booth, R. S.; Botha, D. H.; Boyana, L.; Brederode, L. R. S.; Burge, J. P.; Cheetham, T.; Conradie, J.; Conradie, J. P.; Davidson, D. B.; De Bruin, G.; De Swardt, B.; De Villiers, C.; De Villiers, D. I. L.; De Villiers, M. S.; De Villiers, W.; De Waal, C.; Dikgale, M. A.; Du Toit, G.; Du Toit, L. J.; Esterhuyse, S. W. P.; Fanaroff, B.; Fataar, S.; Foley, A. R.; Foste, G.; Fourie, D.; Gamatham, R.; Gatsi, T.; Geschke, R.; Goedhart, S.; Grobler, T. L.; Gumede, S. C.; Hlakola, M. J.; Hokwana, A.; Hoorn, D. H.; Horn, D.; Horrell, J.; Hugo, B.; Isaacson, A.; Jacobs, O.; Jansen Van Rensburg, J. P.; Jonas, J. L.; Jordaan, B.; Joubert, A.; Joubert, F.; Jozsa, G. I. G.; Julie, R.; Julius, C. C.; Kapp, F.; Karastergiou, A.; Karels, F.; Kariseb, M.; Karuppusamy, R.; Kasper, V.; Knox-Davies, E. C.; Koch, D.; Kotze, P. P. A.; Krebs, A.; Kriek, N.; Kriel, H.; Kusel, T.; Lamoor, S.; Lehmensiek, R.; Liebenberg, D.; Liebenberg, I.; Lord, R. T.; Lunsky, B.; Mabombo, N.; Macdonald, T.; Macfarlane, P.; Madisa, K.; Mafhungo, L.; Magnus, L. G.; Magozore, C.; Mahgoub, O.; Main, J. P. L.; Makhathini, S.; Malan, J. A.; Malgas, P.; Manley, J. R.; Manzini, M.; Marais, L.; Marais, N.; Marais, S. J.; Maree, M.; Martens, A.; Matshawule, S. D.; Matthysen, N.; Mauch, T.; McNally, L. D.; Merry, B.; Millenaar, R. P.; Mjikelo, C.; Mkhabela, N.; Mnyandu, N.; Moeng, I. T.; Mokone, O. J.; Monama, T. E.; Montshiwa, K.; Moss, V.; Mphego, M.; New, W.; Ngcebetsha, B.; Ngoasheng, K.; Niehaus, H.; Ntuli, P.; Nzama, A.; Obies, F.; Obrocka, M.; Ockards, M. T.; Olyn, C.; Oozeer, N.; Otto, A. J.; Padayachee, Y.; Passmoor, S.; Patel, A. A.; Paula, S.; Peens-Hough, A.; Pholoholo, B.; Prozesky, P.; Rakoma, S.; Ramaila, A. J. T.; Rammala, I.; Ramudzuli, Z. R.; Rasivhaga, M.; Ratcliffe, S.; Reader, H. C.; Renil, R.; Richter, L.; Robyntjies, A.; Rosekrans, D.; Rust, A.; Salie, S.; Sambu, N.; Schollar, C. T. G.; Schwardt, L.; Seranyane, S.; Sethosa, G.; Sharpe, C.; Siebrits, R.; Sirothia, S. K.; Slabber, M. J.; Smirnov, O.; Smith, S.; Sofeya, L.; Songqumase, N.; Spann, R.; Stappers, B.; Steyn, D.; Steyn, T. J.; Strong, R.; Struthers, A.; Struthers, A.; Stuart, C.; Sunnylall, P.; Swart, P. S.; Taljaard, B.; Tasse, C.; Taylor, G.; Theron, I. P.; Thondikulam, V.; Thorat, K.; Tiplady, A.; Toruvanda, O.; Van Aardt, J.; Van Balla, T.; Van den Heever, L.; Van der Byl, A.; Van der Merwe, C.; Van der Merwe, P.; Van Niekerk, P. C.; Van Rooyen, R.; Van Staden, J. P.; Van Tonder, V.; Van Wyk, R.; Wait, I.; Walker, A. L.; Wallace, B.; Welz, M.; Williams, L. P.; Xaia, B.; Young, N.; Zitha, S.
    New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622–4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100× larger than during its dormant state. The X-ray flux one month after reactivation was at least 800× larger than during quiescence, and has been decaying exponentially on a 111 ± 19 day timescale. This high-flux state, together with a radio-derived rotational ephemeris, enabled for the first time the detection of X-ray pulsations for this magnetar. At 5%, the 0.3–6 keV pulsed fraction is comparable to the smallest observed for magnetars. The overall pulsar geometry inferred from polarized radio emission appears to be broadly consistent with that determined 6–8 years earlier. However, rotating vector model fits suggest that we are now seeing radio emission from a different location in the magnetosphere than previously. This indicates a novel way in which radio emission from magnetars can differ from that of ordinary pulsars. The torque on the neutron star is varying rapidly and unsteadily, as is common for magnetars following outburst, having changed by a factor of 7 within six months of reactivation.
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    Viewing 'the other' over a hundred and a score more years : South Africa and Russia (1890–2010)
    (AOSIS, 2010-03-30) Liebenberg, I.
    Whether novel is history or history is novel, is a tantalising point. “The novel is no longer a work, a thing to make las t, to connect the pas t with the future but (only) one current event among many, a ges ture with no tomorrow” Kundera (1988:19). One does not have to agree with Kundera to find that social sciences , as his toriography holds a s tory, a human narrative to be shared when focused on a case or cases. In this case, relations between peoples over more than a century are discussed. At the same time, what is known as broader casing in qualitative studies enters the picture. The relations between the governments and the peoples of South Africa and Russia ( including the Soviet Union), sometimes in conflict or peace and sometimes at variance are discussed. Past and present communalities and differences between two national entities within a changing international or global context deserve attention while moments of auto-ethnography compliment the study. References are made to the international political economy in the context of the relations between these countries.