Now showing items 21-33 of 33

    • LOFAR/H-ATLAS: A deep low-frequency survey of the Herschel-ATLAS North Galactic Pole field 

      Hardcastle, M. J.; Gürkan, G.; Weeren, R. J. van; Williams, W. L.; Best, P. N.; Gasperin, F. de; Rafferty, D. A.; Read, S. C.; Sabater, J.; Shimwell, T. W.; Smith, D. J. B.; Tasse, C.; Bourne, N.; Brienza, M.; Brüggen, M.; Brunetti, G.; Chyży, K. T.; Conway, J.; Dunne, L.; Eales, S. A.; Maddox, S. J.; Jarvis, M. J.; Mahony, E. K.; Morganti, R.; Prandoni, I.; Röttgering, H. J. A.; Valiante, E.; White, G. J. (2016-10-21)
      We present LOFAR High-Band Array (HBA) observations of the Herschel-ATLAS North Galactic Pole survey area. The survey we have carried out, consisting of four pointings covering around 142 square degrees of sky in the ...
    • The LoTSS view of radio AGN in the local Universe. The most massive galaxies are always switched on 

      Sabater, J.; Best, P.N.; Hardcastle, M. J.; Shimwell, T. W.; Tasse, C.; Williams, W. L.; Brüggen, M.; Cochrane, R. K.; Croston, J. H.; Gasperin, F. de; Duncan, K. J.; Gürkan, G.; Mechev, A. P.; Morabito, Leah K.; Prandoni, I.; Röttgering, H. J. A.; Smith, D. J. B.; Harwood, J. J.; Mingo, B.; Mooney, S.; Saxena, A. (2018-11-15)
      This paper presents a study of the local radio source population, by cross-comparing the data from the first data release (DR1) of the LOFAR Two-Metre Sky Survey (LoTSS) with the Sloan Digital Sky Survey (SDSS) DR7 main ...
    • Nearby galaxies in the LOFAR Two-metre Sky Survey : I. Insights into the non-linearity of the radio–SFR relation 

      Heesen, V.; Staffehl, M.; Basu, A.; Beck, R.; Stein, M.; Tabatabaei, F. S.; Hardcastle, M. J.; Chyży, K. T.; Shimwell, T. W.; Adebahr, B.; Beswick, R.; Bomans, D. J.; Botteon, A.; Brinks, E.; Brüggen, M.; Dettmar, R. -J.; Drabent, A.; Gasperin, F. de; Gürkan, G.; Heald, G. H.; Horellou, C.; Nikiel-Wroczynski, B.; Paladino, R.; Piotrowska, J.; Röttgering, H. J. A.; Smith, D. J. B.; Tasse, C. (2022-08-08)
      Context. Cosmic rays and magnetic fields are key ingredients in galaxy evolution, regulating both stellar feedback and star formation. Their properties can be studied with low-frequency radio continuum observations, free ...
    • The Planck clusters in the LOFAR sky. I. LoTSS-DR2 new detections and sample overview 

      Botteon, A.; Shimwell, T. W.; Cassano, R.; Cuciti, V.; Zhang, X.; Bruno, L.; Camillini, L.; Natale, R.; Jones, A.; Gastaldello, F.; Simionescu, A.; Rossetti, M.; Akamatsu, H.; Weeren, R. J. van; Brunetti, G.; Brüggen, M.; Groenveld, C.; Hoang, D. N.; Hardcastle, M. J.; Ignesti, A.; Gennaro, G. Di; Bonafede, A.; Drabent, A.; Röttgering, H. J. A.; Hoeft, M.; Gasperin, F. de (2022-04-30)
      Context. Relativistic electrons and magnetic fields permeate the intra-cluster medium (ICM) and manifest themselves as diffuse sources of synchrotron emission observable at radio wavelengths, namely radio halos and radio ...
    • A plethora of diffuse steep spectrum radio sources in Abell 2034 revealed by LOFAR 

      Shimwell, T. W.; Luckin, J.; Brüggen, M.; Brunetti, G.; Intema, H. T.; Owers, M. S.; Röttgering, H. J. A.; Stroe, A.; Weeren, R. J. van; Williams, W. L.; Cassano, R.; Gasperin, F. de; Heald, G. H.; Hoang, D. N.; Hardcastle, M.J.; Sridhar, S. S.; Sabater, J.; Best, P. N.; Bonafede, A.; Chyży, K. T.; Ensslin, T. A.; Ferrari, C.; Haverkorn, M.; Hoeft, M.; Horellou, C.; McKean, J. P.; Morabito, L. K.; Orrù, E.; Pizzo, R.; Retana-Montenegro, E.; White, G.J. (2016-06-11)
      With Low-Frequency Array (LOFAR) observations, we have discovered a diverse assembly of steep spectrum emission that is apparently associated with the intra cluster medium (ICM) of the merging galaxy cluster Abell 2034. ...
    • The population of M dwarfs observed at low radio frequencies 

      Callingham, J. R.; Vedantham, H. K.; Shimwell, T. W.; Pope, B. J. S.; Davis, I. E.; Best, P. N.; Hardcastle, M. J.; Rottgering, H. J. A.; Sabater, J.; Tasse, C.; Weeren, R. J. van; Williams, W. L.; Zarka, P.; Gasperin, F. de; Drabent, A. (2021-10-11)
      Coherent low-frequency (≲200 MHz) radio emission from stars encodes the conditions of the outer corona, mass-ejection events and space weather 1–5. Previous low-frequency searches for radio-emitting stellar systems have ...
    • Radio-loud AGN in the first LoTSS data release: The lifetimes and environmental impact of jet-driven sources 

      Hardcastle, M. J.; Williams, W. L.; Best, P. N.; Croston, J. H.; Duncan, K. J.; Rottgering, H. J. A.; Sabater, J.; Shimwell, T. W.; Tasse, C.; Callingham, J. R.; Cochrane, R. K.; Gasperin, F. de; Gurkan, G.; Jarvis, M. J.; Mahatma, V.; Miley, G. K.; Mingo, B.; Mooney, S.; Morabito, L. K.; O'Sullivan, S. P.; Prandoni, I.; Shulevski, A.; Smith, D. J. B. (2018-11-19)
      We constructed a sample of 23,344 radio-loud active galactic nuclei (RLAGN) from the catalogue derived from the LOFAR Two-Metre Sky Survey (LoTSS) survey of the HETDEX Spring field. Although separating AGN from star-forming ...
    • Revived Fossil Plasma Sources in Galaxy Clusters 

      Mandal, S.; Intema, H. T.; Weeren, R. J. van; Shimwell, T. W.; Botteon, A.; Brunetti, G.; Gasperin, F. de; Brüggen, M.; Gennaro, G. Di; Kraft, R.; Röttgering, H. J. A.; Hardcastle, M.; Tasse, C. (2020-01-28)
      It is well established that particle acceleration by shocks and turbulence in the intra-cluster medium can produce cluster-scale synchrotron emitting sources. However, the detailed physics of these particle acceleration ...
    • Signatures from a merging galaxy cluster and its AGN population : LOFAR observations of Abell 1682 

      Clarke, A. O.; Scaife, Anna M.M.; Shimwell, T.; Weeren, R. J. van; Bonafede, A.; Heald, George; Brunetti, G.; Cantwell, T. M.; Gasperin, F. de; Brüggen, M.; Botteon, A.; Hoeft, M.; Horellou, C.; Cassano, R.; Harwood, J. J.; Röttgering, H. J. A. (2019-07-05)
      We present LOFAR data from 110-180 MHz of the merging galaxy cluster Abell 1682, alongside archival optical, radio, and X-ray data. Our images of 6 arcsec in resolution at low frequencies reveal new structures associated ...
    • A snapshot of the oldest AGN feedback phases 

      Brienza, M.; Shimwell, T. W.; Gasperin, F. de; Bikmaev, I.; Bonafede, A.; Botteon, A.; Brüggen, M.; Brunetti, G.; Burenin, R.; Capetti, A.; Churazov, E.; Hardcastle, M. J.; Khabibullin, I.; Lyskova, N.; R öttgering, H. J. A.; Sunyaev, R.; Weeren, R. J. van; Gastaldello, F.; Mandal, S.; Purser, S.; Simionescu, A.; Tasse, C. (2021-10-18)
      Active Galactic Nuclei (AGN) inject large amounts of energy into their host galaxies and surrounding environment, shaping their properties and evolution. In particular, AGN jets inflate cosmic-ray lobes, which can rise ...
    • 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 ...
    • 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, ...
    • VICTORIA project: The LOFAR HBA Virgo Cluster Survey 

      Edler, H. W.; Gasperin, F. de; Shimwell, T. W.; Hardcastle, M. J.; Boselli, A.; Heesen, V.; McCall, H.; Bomans, D. J.; Brüggen, M.; Bulbul, E.; Chŷzy, K. T.; Ignesti, A.; Merloni, A.; Pacaud, F.; Reiprich, T. H.; Roberts, I. D.; Rottgering, H. J. A.; Weeren, R. J. van (2023-06-02)
      Context. The Virgo cluster is the nearest (d = 16.5 Mpc) massive (M ≥ 1014 M⊙) galaxy cluster and is therefore a prime target for studying astrophysical processes in dense large-scale environments. In the radio band, we ...