Browsing by Author "Orru, E."

Now showing items 1-8 of 8

    • The intergalactic magnetic field probed by a giant radio galaxy 

      O'Sullivan, S. P.; Machalski, J.; Eck, C. L. Van; Heald, G.; Brueggen, M.; Fynbo, J. P. U.; Heintz, K. E.; Lara-Lopez, M. A.; Vacca, V.; Hardcastle, M. J.; Shimwell, T. W.; Tasse, C.; Vazza, F.; Andernach, H.; Birkinshaw, M.; Haverkorn, M.; Horellou, C.; Williams, W. L.; Harwood, J. J.; Brunetti, G.; Anderson, J. M.; Mao, S. A.; Nikiel-Wroczynski, B.; Takahashi, K.; Carretti, E.; Vernstrom, T.; Weeren, R. J. van; Orru, E.; Morabito, L. K.; Callingham, J. R. (2018-10-09)
      Cosmological simulations predict that an intergalactic magnetic field (IGMF) pervades the large scale structure (LSS) of the Universe. Measuring the IGMF is important to determine its origin (i.e. primordial or otherwise). ...

    • LOFAR imaging of Cygnus A - direct detection of a turnover in the hotspot radio spectra 

      McKean, J. P.; Godfrey, L. E H; Vegetti, S.; Wise, Michael W.; Morganti, R.; Hardcastle, M. J.; Rafferty, D.; Avruch, I. M.; Beck, R.; Bell, M. E.; Bemmel, I. M. van; Bentum, M. J.; Bernardi, G.; Best, Philip; Blaauw, R.; Bonafede, A.; Breitling, F.; Broderick, J. W.; Brüggen, Marcus; Cerrigone, L.; Ciardi, B.; De Gasperin, Francesco; Deller, A.; Duscha, S.; Engels, D.; Falcke, H.; Fallows, R. A.; Frieswijk, W.; Garrett, M.A.; Grießmeier, J. -M.; Haarlem, M. P. van; Heald, G.; Hoeft, Matthias; van der, HorstA J.; Iacobelli, M.; Interna, H.; Juette, E.; Karastergiou, A.; Kondratiev, V. I.; Koopmans, L. V E; Kuniyoshi, M.; Kuper, G.; Van Leeuwen, J.; Maat, P.; Mann, R. G.; Markoff, S.; McFadden, R.; McKay-Bukowski, D.; Mulcahy, D. D.; Munk, H.; Nelles, A.; Orru, E.; Paas, H.; Pandey-Pommier, M.; Pietka, M.; Pizzo, R.; Polatidis, A. G.; Reich, W.; Rottgering, H. J. A.; Rowlinson, A.; Scaife, A. M M; Serylak, M.; Shulevski, Alexander; Sluman, J.; Smirnov, O.; Steinmetz, M.; Stewart, A. J.; Swinbank, J.; Tagger, M.; Thoudam, S.; Toribio, M. C.; Vermeulen, R.; Vocks, C.; Van Weeren, R. J.; Wucknitz, O.; Yatawatta, S.; Zarka, P. (2016-12-01)
      The low-frequency radio spectra of the hotspots within powerful radio galaxies can provide valuable information about the physical processes operating at the site of the jet termination. These processes are responsible for ...

    • The LOFAR LBA Sky Survey I. survey description and preliminary data release 

      Gasperin, F. de; Williams, W. L.; Best, P.; Bruggen, M.; Brunetti, G.; Cuciti, V.; Dijkema, T. J.; Hardcastle, M. J.; Norden, M. J.; Offringa, A.; Shimwell, T.; Weeren, R. van; Bomans, D.; Bonafede, A.; Botteon, A.; Callingham, J. R.; Cassano, R.; Chyzy, K. T.; Emig, K. L.; Edler, H.; Haverkorn, M.; Heald, G.; Heesen, V.; Iacobelli, M.; Intema, H. T.; Kadler, M.; Malek, K.; Mevius, M.; Miley, G.; Mingo, B.; Morabito, L. K.; Sabater, J.; Morganti, R.; Orru, E.; Pizzo, R.; Prandoni, I.; Shulevski, A.; Tasse, C.; Vaccari, M.; Zarka, P.; Rottgering, H. (2021-02-17)
      Context. The LOw Frequency ARray (LOFAR)istheonlyradiotelescopethatispresentlycapableofhigh-sensitivity,high-resolution (i.e. < 1mJybeam−1 and < 1500) observations at ultra-low frequencies(< 100MHz). To utilise these ...

    • LOFAR MSSS: Detection of a low-frequency radio transient in 400 hrs of monitoring of the North Celestial Pole 

      Stewart, A. J.; Fender, R.P.; Broderick, J. W.; Hassall, T. E.; Muñoz-Darias, T.; Rowlinson, A.; Swinbank, J. D.; Staley, T. D.; Molenaar, G. J.; Scheers, B.; Grobler, T. L.; Pietka, M.; Heald, G.; McKean, J. P.; Bell, M. E.; Bonafede, A.; Breton, R. P.; Carbone, D.; Cendes, Y.; Clarke, A. O.; Corbel, S.; Gasperin, F. de; Eislöffel, J.; Falcke, H.; Ferrari, C.; Grießmeier, J. -M.; Hardcastle, M.J.; Heesen, V.; Hessels, J. W. T.; Horneffer, A.; Iacobelli, M.; Jonker, P.; Karastergiou, A.; Kokotanekov, G.; Kondratiev, V. I.; Kuniyoshi, M.; Law, C. J.; Leeuwen, J. van; Markoff, S.; Miller-Jones, J. C. A.; Mulcahy, D.; Orru, E.; Pandey-Pommier, M.; Pratley, L.; Rol, E.; Röttgering, H. J. A.; Scaife, A. M. M.; Shulevski, A.; Sobey, C. A.; Stappers, B. W.; Tasse, C.; van der Horst, A.J.; Velzen, S. van; Weeren, R. J. van; Wijers, R.A.M.J.; Wijnands, R.; Wise, M.; Zarka, P.; Alexov, A.; Anderson, J.; Asgekar, A.; Avruch, I. M.; Bentum, M. J.; Bernardi, G.; Best, P.; Breitling, F.; Brüggen, M.; Butcher, H. R.; Ciardi, B.; Conway, J. E.; Corstanje, A.; Geus, E. de; Deller, A.; Duscha, S.; Frieswijk, W.; Garrett, M.A.; Gunst, A. W.; Haarlem, M. P. van; Hoeft, M.; Hörandel, J.; Juette, E.; Kuper, G.; Loose, M.; Maat, P.; McFadden, R.; McKay-Bukowski, D.; Moldon, J.; Munk, H.; Norden, M. J.; Paas, H.; Polatidis, A. G.; Schwarz, D.; Sluman, J.; Smirnov, O.; Steinmetz, M.; Thoudam, S.; Toribio, M. C.; Vermeulen, R.; Vocks, C.; Wijnholds, S. J.; Wucknitz, O.; Yatawatta, S. (2016-03-01)
      We present the results of a four-month campaign searching for low-frequency radio transients near the North Celestial Pole with the Low-Frequency Array (LOFAR), as part of the Multifrequency Snapshot Sky Survey (MSSS). The ...

    • LOFAR MSSS: Discovery of a 2.56 Mpc giant radio galaxy associated with a disturbed galaxy group 

      Clarke, A. O.; Heald, G.; Jarrett, T.; Bray, J. D.; Hardcastle, Martin; Cantwell, T. M.; Scaife, A. M. M.; Brienza, M.; Bonafede, A.; Breton, R. P.; Broderick, J. W.; Carbone, D.; Croston, J. H.; Farnes, J. S.; Harwood, J. J.; Heesen, V.; Horneffer, A.; Horst, A. J. van der; Iacobelli, M.; Jurusik, W.; Kokotanekov, G.; McKean, J. P.; Morabito, L. K.; Mulcahy, D. D.; Nikiel-Wroczynski, B. S.; Orru, E.; Paladino, R.; Pandey-Pommier, M.; Pietka, M.; Pizzo, R.; Pratley, L.; Riseley, C. J.; Rottgering, H. J. A.; Rowlinson, A.; Sabater, J.; Sendlinger, K.; Shulevski, A.; Sridhar, S. S.; Stewart, A. J.; Tasse, C.; Velzen, S. van; Weeren, R. J. van; Wise, M. W. (2017-05-01)
      We report on the discovery in the LOFAR Multifrequency Snapshot Sky Survey (MSSS) of a giant radio galaxy (GRG) with a projected size of $2.56 \pm 0.07$ Mpc projected on the sky. It is associated with the galaxy triplet ...

    • Low-frequency observations of the Giant Radio Galaxy NGC 6251 

      Cantwell, T. M.; Bray, J. D.; Croston, J. H.; Scaife, A. M. M.; Mulcahy, D. D.; Best, P. N.; Bruggen, M.; Brunetti, G.; Callingham, J. R.; Clarke, A. O.; Hardcastle, M. J.; Harwood, J. J.; Heald, G.; Heesen, V.; Iacobelli, M.; Jamrozy, M.; Morganti, R.; Orru, E.; O'Sullivan, S. P.; Riseley, C. J.; Rottgering, H. J. A.; Shulevski, A.; Sridhar, S. S.; Tasse, C.; Eck, C. L. Van (2020-06-01)
      We present LOFAR observations at 150 MHz of the borderline FRI/FRII giant radio galaxy NGC 6251. This paper presents the most sensitive and highest-resolution images of NGC 6251 at these frequencies to date, revealing for ...

    • The spectral structure and energetics of powerful radio sources 

      Harwood, J. J.; Hardcastle, M J.; Croston, J. H.; Stroe, A.; Morganti, R.; Orru, E. (2014-04-29)
      Determining the energy spectrum of an electron population can give key insights into the underlying physics of a radio source; however, the lack of high resolution, broad-bandwidth observations has left many ambiguities ...

    • Sub-arcsecond imaging with the International LOFAR Telescope : I. Foundational calibration strategy and pipeline 

      Morabito, L. K.; Jackson, N. J.; Mooney, S.; Sweijen, F.; Badole, S.; Kukreti, P.; Venkattu, D.; Groeneveld, C.; Kappes, A.; Bonnassieux, E.; Drabent, A.; Iacobelli, M.; Croston, J. H.; Best, P. N.; Bondi, M.; Callingham, J. R.; Conway, J. E.; Deller, A. T.; Hardcastle, M. J.; McKean, J. P.; Miley, G. K.; Moldon, J.; Röttgering, H. J. A.; Tasse, C.; Shimwell, T. W.; Weeren, R. J. van; Anderson, J. M.; Asgekar, A.; Avruch, I. M.; Bemmel, I. M. van; Bentum, M. J.; Bonafede, A.; Brouw, W. N.; Butcher, H. R.; Ciardi, B.; Corstanje, A.; Coolen, A.; Damstra, S.; Gasperin, F. de; Duscha, S.; Eislöffel, J.; Engels, D.; Falcke, H.; Garrett, M. A.; Griessmeier, J.; Gunst, A. W.; Haarlem, M. P. van; Hoeft, M.; Horst, A. J. van der; Jütte, E.; Kadler, M.; Koopmans, L. V. E.; Krankowski, A.; Mann, G.; Nelles, A.; Oonk, J. B. R.; Orru, E.; Paas, H.; Pandey, V. N.; Pizzo, R. F.; Pandey-Pommier, M.; Reich, W.; Rothkaehl, H.; Ruiter, M.; Schwarz, D. J.; Shulevski, A.; Soida, M.; Tagger, M.; Vocks, C.; Wijers, R. A. M. J.; Wijnholds, S. J.; Wucknitz, O.; Zarka, P.; Zucca, P. (2022-02-28)
      The International LOFAR Telescope is an interferometer with stations spread across Europe. With baselines of up to ∼2000 km, LOFAR has the unique capability of achieving sub-arcsecond resolution at frequencies below 200 ...