Browsing University of Hertfordshire by Author "Shimwell, Timothy W."

Now showing items 1-6 of 6

    • Faceting for direction-dependent spectral deconvolution 

      Tasse, C.; Hugo, B.; Mirmont, M.; Smirnov, O.; Atemkeng, M.; Bester, L.; Bonnassieux, E.; Hardcastle, M. J.; Lakhoo, R.; Girard, J.H.V.; Makhathini, S.; Perkins, S.; Shimwell, Timothy W. (2018-03-01)
      The new generation of radio interferometers is characterized by high sensitivity, wide fields of view and large fractional bandwidth. To synthesize the deepest images enabled by the high dynamic range of these instruments ...

    • Faraday tomography of LoTSS-DR2 data : I. Faraday moments in the high-latitude outer Galaxy and revealing Loop III in polarisation 

      Erceg, Ana; Jelić, Vibor; Haverkorn, Marijke; Bracco, Andrea; Shimwell, Timothy W.; Tasse, Cyril; Dickey, John M.; Ceraj, Lana; Drabent, Alexander; Hardcastle, Martin J.; Turić, Luka (2022-07-01)
      Context. Observations of synchrotron emission at low radio frequencies reveal a labyrinth of polarised Galactic structures. However, the explanation for the wealth of structures remains uncertain due to the complex ...

    • Filaments in the southern giant lobe of Centaurus A : Constraints on nature and origin from modelling and GMRT observations 

      Wykes, Sarka; Intema, Huib T.; Hardcastle, M.J.; Achterberg, Abraham; Jones, Thomas W.; Jerjen, Helmut; Orrú, Emanuela; Lazarian, Alex; Shimwell, Timothy W.; Wise, Michael W.; Kronberg, Philipp P. (2014-08-21)
      We present results from imaging of the radio filaments in the southern giant lobe of CentaurusA using data from Giant Metrewave Radio Telescope observations at 325 and 235 MHz, and outcomes from filament modelling. The ...

    • Investigating the Unification of LOFAR-detected powerful AGN in the Boötes Field 

      Morabito, Leah K.; Williams, W. L.; Duncan, Kenneth J.; Röttgering, H.~J.~A.; Miley, George; Saxena, Aayush; Barthel, Peter; Best, Philip N.; Bruggen, M.; Brunetti, G.; Chyży, K. T.; Engels, D.; Hardcastle, M. J.; Harwood, J. J.; Jarvis, Matt J.; Mahony, E. K.; Prandoni, I.; Shimwell, Timothy W.; Shulevski, Alexander; Tasse, C. (2017-08-01)
      Low radio frequency surveys are important for testing unified models of radio-loud quasars and radio galaxies. Intrinsically similar sources that are randomly oriented on the sky will have different projected linear sizes. ...

    • Search and modelling of remnant radio galaxies in the LOFAR Lockman Hole field 

      Brienza, M.; Godfrey, L.; Morganti, R.; Prandoni, I.; Harwood, J.; Mahony, E. K.; Hardcastle, M. J.; Murgia, Matteo; Röttgering, H.~J.~A.; Shimwell, Timothy W.; Shulevski, Aleksander (2017-10-20)
      The phase of radio galaxy evolution after the jets have switched off, often referred to as the remnant phase, is poorly understood and very few sources in this phase are known. In this work we present an extensive search ...

    • 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 ...