Now showing items 1-6 of 6

    • High-resolution international LOFAR observations of 4C~43.15 -- Spectral ages and injection indices in a high-z radio galaxy 

      Sweijen, Frits; Morabito, Leah K.; Harwood, Jeremy; Weeren, Reinout J. van; Röttgering, Huub J. A.; Callingham, Joseph R.; Jackson, Neal; Miley, George; Moldon, Javier (2022-02-01)
      It has long been known that radio sources with the steepest spectra are preferentially associated with the most distant galaxies, the α - z relation, but the reason for this relation is an open question. The spatial ...
    • Investigating the spectral age problem with powerful radio galaxies 

      Mahatma, Vijay H.; Hardcastle, Martin J.; Croston, Judith H.; Harwood, Jeremy; Ineson, Judith; Moldon, Javier (2020-02-01)
      The 'spectral age problem' is our systematic inability to reconcile the maximum cooling time of radiating electrons in the lobes of a radio galaxy with its age as modelled by the dynamical evolution of the lobes. While ...
    • The resolved jet of 3C 273 at 150 MHz : Sub-arcsecond imaging with the LOFAR international baselines 

      Harwood, Jeremy J.; Mooney, Sean; Morabito, Leah K.; Quinn, John; Sweijen, Frits; Groeneveld, Christian; Bonnassieux, Etienne; Kappes, Alexander; Moldon, Javier (2022-02-01)
      Context. Since its discovery in 1963, 3C 273 has become one of the most widely studied quasars with investigations spanning the electromagnetic spectrum. While much has therefore been discovered about this historically ...
    • Sub-arcsecond imaging with the International LOFAR Telescope. II. Completion of the LOFAR Long-Baseline Calibrator Survey 

      Jackson, Neal; Badole, Shruti; Chhetri, Rajan; Prusis, Kaspars; Nikolajevs, Atvars; Morabito, Leah; Brentjens, Michiel; Sweijen, Frits; Iacobelli, Marco; Orrù, Emanuela; Sluman, J.; Blaauw, R.; Mulder, H.; Dijk, P. van; Mooney, Sean; Deller, Adam; Moldon, Javier; Callingham, J. R.; Harwood, Jeremy; Hardcastle, Martin; Heald, George; Drabent, Alexander; McKean, J. P.; Asgekar, A.; Avruch, I. M.; Bentum, M. J.; Bonafede, A.; Brouw, W. N.; Brüggen, M.; Butcher, H. R.; Ciardi, B.; Coolen, A.; Corstanje, A.; Damstra, S.; Duscha, S.; Eislöffel, J.; Falcke, H.; Garrett, M.; Gasperin, F. de; Griessmeier, J. -M.; Gunst, A. W.; Haarlem, M. P. van; Hoeft, M.; Horst, A. J. van der; Jütte, E.; Koopmans, L. V. E.; Krankowski, A.; Maat, P.; Mann, G.; Miley, G. K.; Nelles, A.; Norden, M.; Paas, M.; Pandey, V. N.; Pandey-Pommier, M.; Pizzo, R. F.; Reich, W.; Rothkaehl, H.; Rowlinson, A.; Ruiter, M.; Shulevski, A.; Schwarz, D. J.; Smirnov, O.; Tagger, M.; Vocks, C.; Weeren, R. J. van; Wijers, R.; Wucknitz, O.; Zarka, P.; Zensus, J. A.; Zucca, P. (2022-02-01)
      The Low-Frequency Array (LOFAR) Long-Baseline Calibrator Survey (LBCS) was conducted between 2014 and 2019 in order to obtain a set of suitable calibrators for the LOFAR array. In this paper, we present the complete survey, ...
    • Subarcsecond view on the high-redshift blazar GB 1508+5714 by the International LOFAR Telescope 

      Kappes, A.; Burd, P. R.; Kadler, M.; Ghisellini, G.; Bonnassieux, E.; Perucho, M.; Brüggen, Marcus; Cheung, C. C.; Ciardi, B.; Gallo, E.; Haardt, F.; Morabito, Leah K.; Sbarrato, T.; Drabent, A.; Harwood, J.; Jackson, N. J.; Moldon, Javier (2022-07-12)
      Context. Studies of the most distant active galactic nuclei (AGNs) allow us to test our current understanding of the physics present in radio-jetted AGNs across a range of environments, and probe their interactions with ...
    • Unmasking the history of 3C 293 with LOFAR sub‐arcsecond imaging 

      Kukreti, Pranav; Morganti, Raffaella; Shimwell, Timothy W.; Morabito, Leah K.; Beswick, Robert J.; Brienza, Marisa; Hardcastle, Martin J.; Sweijen, Frits; Jackson, Neal; Miley, George K.; Moldon, Javier; Oosterloo, Tom; Gasperin, Francesco de (2021-12-07)
      Active galactic nuclei show episodic activity, which can be evident in galaxies that exhibit restarted radio jets. These restarted jets can interact with their environment, leaving signatures in the radio spectral energy ...