Now showing items 1-20 of 27

    • The best of both worlds : Combining LOFAR and Apertif to derive resolved radio spectral index images 

      Morganti, R.; Oosterloo, T. A.; Brienza, M.; Jurlin, N.; Prandoni, I.; Orru', E.; Shabala, S. S.; Adams, E. A. K.; Adebahr, B.; Best, P. N.; Coolen, A. H. W. M.; Damstra, S.; Blok, W. J. G. de; Gasperin, F. de; Denes, H.; Hardcastle, M.; Hess, K. M.; Hut, B.; Kondapally, R.; Kutkin, A. M.; Loose, G. M.; Lucero, D. M.; Maan, Y.; Maccagni, F. M.; Mingo, B.; Moss, V. A.; Mostert, R. I. J.; Norden, M. J.; Oostrum, L. C.; Rottgering, H. J. A.; Ruiter, M.; Shimwell, T. W.; Schulz, R.; Vermaas, N. J.; Vohl, D.; Hulst, J. M. van der; Diepen, G. M. van; Leeuwen, J. van; Ziemke, J. (2021-04-07)
      Supermassive black holes at the centres of galaxies can cycle through periods of activity and quiescence. Characterising the duty cycle of active galactic nuclei is crucial for understanding the impact of the energy they ...
    • The bright end of the infrared luminosity functions and the abundance of hyperluminous infrared galaxies 

      Wang, L.; Gao, F.; Best, P. N.; Duncan, K.; Hardcastle, M. J.; Kondapally, R.; Malek, K.; McCheyne, I.; Sabater, J.; Shimwell, T.; Tasse, C.; Bonato, M.; Bondi, M.; Cochrane, R. K.; Farrah, D.; Gurkan, G.; Haskell, P.; Pearson, W. J.; Prandoni, I.; Rottgering, H. J. A.; Smith, D. J. B.; Vaccari, M.; Williams, W. L. (2021-04-07)
      We provide the most accurate estimate yet of the bright end of the infrared (IR) luminosity functions (LFs) and the abundance of hyperluminous IR galaxies (HLIRGs) with IR luminosities > 10^13 L_solar, thanks to the ...
    • The contribution of discrete sources to the sky temperature at 144 MHz 

      Hardcastle, M. J.; Shimwell, T. W.; Tasse, C.; Best, P. N.; Drabent, A.; Jarvis, M. J.; Prandoni, I.; Rottgering, H. J. A.; Sabater, J.; Schwarz, D. J. (2021-04-07)
      In recent years, the level of the extragalactic radio background has become a point of considerable interest, with some lines of argument pointing to an entirely new cosmological synchrotron background. The contribution ...
    • Discovery of 24 radio-bright quasars at $4.9 \leq z \leq6.6$ using low-frequency radio observations 

      Gloudemans, A. J.; Duncan, K. J.; Saxena, A.; Harikane, Y.; Hill, G. J.; Zeimann, G. R.; Rottgering, H. J. A.; Yang, D.; Best, P. N.; Banados, E.; Drabent, A.; Hardcastle, M. J.; Hennawi, J. F.; Lansbury, G.; Magliocchetti, M.; Miley, G. K.; Nanni, R.; Shimwell, T. W.; Smith, D. J. B.; Venemans, B.P.; Wagenveld, J. D. (2022-12-31)
      High redshift quasars ($z>5$) that also shine brightly at radio wavelengths are unique signposts of supermassive black hole activity in the early universe. However, bright radio sources at $z\ge5$ are extremely rare and ...
    • The e-MERLIN Galaxy Evolution Survey (e-MERGE) : Overview and Survey Description 

      Muxlow, T. W. B.; Wrigley, N. H.; Beswick, R. J.; Smail, Ian; McHardy, I. M.; Garrington, S. T.; Ivison, R. J.; Jarvis, M. J.; Prandoni, I.; Bondi, M.; Guidetti, D.; Argo, M. K.; Bacon, David; Best, P. N.; Biggs, A. D.; Chapman, S. C.; Coppin, K.; Chen, H.; Garratt, T. K.; Garrett, M. A.; Ibar, E.; Kneib, Jean-Paul; Knudsen, Kirsten K.; Koopmans, L. V. E.; Morabito, L. K.; Njeri, A.; Pearson, Chris; Perez-Torres, M. A.; Rottgering, H. J. A.; Sargent, M. T.; Serjeant, Stephen; Swinbank, A. M.; Varenius, E.; Venturi, T. (2020-05-08)
      We present an overview and description of the eMERLIN Galaxy Evolution survey (eMERGE) Data Release 1 (DR1), a large program of high-resolution 1.5 GHz radio observations of the GOODS-N field comprising $\sim140$ hours of ...
    • The Far-Infrared Radio Correlation at low radio frequency with LOFAR/H-ATLAS 

      Read, Shaun; Smith, Daniel; Gurkan, Gulay; Hardcastle, Martin; Williams, Wendy Louise; Best, P.N.; Brinks, Elias; Calistro-Rivera, Gabriela; Chyzy, K.T.; Duncan, Kenneth J.; Dunne, Loretta; Jarvis, M. J.; Morabito, Leah K.; Prandoni, I.; Rottgering, H. J. A.; Sabater, Jose; Viaene, Sébastien (2018-11-11)
      The radio and far-infrared luminosities of star-forming galaxies are tightly correlated over several orders of magnitude; this is known as the far-infrared radio correlation (FIRC). Previous studies have shown that a host ...
    • Giant radio galaxies in the LOFAR Two-metre Sky Survey-I 

      Dabhade, P.; Rottgering, H. J. A.; Bagchi, J.; Shimwell, T. W.; Hardcastle, M. J.; Sankhyayan, S.; Morganti, R.; Jamrozy, M.; Shulevski, A.; Duncan, K. J. (2020-03-01)
      Giant radio galaxies (GRGs) are a subclass of radio galaxies which have grown to megaparsec scales. GRGs are much rarer than normal sized radio galaxies ( less than 0.7 Mpc) and the reason for their gigantic sizes is still ...
    • Investigating the spectra and physical nature of galaxy scale jets 

      Webster, B.; Croston, J. H.; Harwood, J. J.; Baldi, R. D.; Hardcastle, M. J.; Mingo, B.; Rottgering, H. J. A. (2021-10-13)
      Previous studies have shown that physically small, low-luminosity radio galaxies, which we refer to as galaxy scale jets (GSJ), could potentially have a significant effect upon the host galaxy's evolution. Using 6 arcsec ...
    • 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 II. First data release 

      Gasperin, F. de; Edler, H. W.; Williams, W. L.; Callingham, J. R.; Asabere, B.; Bruggen, M.; Brunetti, G.; Dijkema, T. J.; Hardcastle, M. J.; Iacobelli, M.; Offringa, A.; Norden, M. J.; Rottgering, H. J. A.; Shimwell, T.; Weeren, R. J. van; Tasse, C.; Bomans, D. J.; Bonafede, A.; Botteon, A.; Cassano, R.; Chyzy, K. T.; Cuciti, V.; Emig, K. L.; Kadler, M.; Miley, G.; Mingo, B.; Oei, M. S. S. L.; Prandoni, I.; Schwarz, D. J.; Zarka, P. (2023-05-26)
      Context. The Low Frequency Array (LOFAR) is the only existing radio interferometer able to observe at ultra-low frequencies (<100 MHz) with high resolution (<15") and high sensitivity (<1 mJy beam-1). To exploit these ...
    • 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 ...
    • The LOFAR Two-metre Sky Survey Deep Fields Data Release 1 V. Survey description, source classifications and host galaxy properties 

      Best, P. N.; Kondapally, R.; Williams, W. L.; Cochrane, R. K.; Duncan, K. J.; Hale, C. L.; Haskell, P.; Malek, K.; McCheyne, I.; Smith, D. J. B.; Wang, L.; Botteon, A.; Bonato, M.; Bondi, M.; Rivera, G. Calistro; Gao, F.; Gurkan, G.; Hardcastle, M. J.; Jarvis, M. J.; Mingo, B.; Miraghaei, H.; Morabito, L. K.; Nisbet, D.; Prandoni, I.; Rottgering, H. J. A.; Sabater, J.; Shimwell, T.; Tasse, C.; Weeren, R. van (2023-08-01)
      Source classifications, stellar masses, and star-formation rates are presented for ≈80 000 radio sources from the first data release of the Low Frequency Array Two-metre Sky Survey (LoTSS) Deep Fields, which represents the ...
    • The LOFAR Two-metre Sky Survey: Deep Fields: : II. The ELAIS-N1 LOFAR deep field 

      Sabater, J.; Best, P. N.; Tasse, C.; Hardcastle, M. J.; Shimwell, T. W.; Nisbet, D.; Jelic, V.; Callingham, J. R.; Rottgering, H. J. A.; Bonato, M.; Bondi, M.; Ciardi, B.; Cochrane, R. K.; Jarvis, M. J.; Kondapally, R.; Koopmans, L. V. E.; O'Sullivan, S. P.; Prandoni, I.; Schwarz, D. J.; Smith, D. J. B.; Wang, L.; Williams, W. L.; Zaroubi, S. (2021-04-07)
      The LOFAR Two-metre Sky Survey (LoTSS) will cover the full northern sky and, additionally, aims to observe the LoTSS deep fields to a noise level of ~10 microJy/bm over several tens of square degrees in areas that have the ...
    • The LOFAR view of FR0 radio galaxies 

      Capetti, A.; Brienza, M.; Baldi, R. D.; Giovannini, G.; Morganti, R.; Hardcastle, M. J.; Rottgering, H. J. A.; Brunetti, G. F.; Best, P. N.; Miley, G. (2020-10-09)
      We explore the low-frequency radio properties of the sources in the Fanaroff-Riley class 0 catalog (FR0CAT) as seen by the LOw Frequency ARray (LOFAR) observations at 150 MHz. This sample includes 104 compact radio active ...
    • The LOFAR view of giant, early-type galaxies: radio emission from active nuclei and star formation 

      Capetti, A.; Brienza, M.; Balmaverde, B.; Best, R. D. P. N.; Baldi, R. D.; Drabent, A.; Gurkan, G.; Rottgering, H. J. A.; Tasse, C.; Webster, B. (2022-02-17)
      We studied the properties and the origin of the radio emission in the most luminous, early-type galaxies (ETGs) in the nearby Universe (MK ≤ −25, recession velocity ≤7500 km s−1), as seen by the 150 MHz Low-Frequency ARray ...
    • A LOFAR-IRAS cross-match study : the far-infrared radio correlation and the 150-MHz luminosity as a star-formation rate 

      Wang, L.; Gao, F.; Duncan, K. J.; Williams, W. L.; Rowan-Robinson, M.; Sabater, J.; Shimwell, T. W.; Bonato, M.; Calistro-Rivera, G.; Chyzy, K. T.; Farrah, D.; Gurkan Uygun, Gulay; Hardcastle, M. J.; McCheyne, I.; Prandoni, I.; Read, S. C.; Rottgering, H. J. A.; Smith, D. J. B. (2019-11-01)
      Aims. We aim to study the far-infrared radio correlation (FIRC) at 150 MHz in the local Universe (at a median redshift z~0:05) and improve the use of the rest-frame 150-MHz luminosity, L150, as a star-formation rate (SFR) ...
    • 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 ...
    • NGC 326: X-shaped no more 

      Hardcastle, M. J.; Croston, J. H.; Shimwell, T. W.; Tasse, C.; Gurkan Uygun, Gulay; Morganti, R.; Murgia, M.; Rottgering, H. J. A.; Weeren, R. J. van; Williams, W. L. (2019-09-01)
      We present new 144-MHz LOFAR observations of the prototypical `X-shaped' radio galaxy NGC 326, which show that the formerly known wings of the radio lobes extend smoothly into a large-scale, complex radio structure. We ...
    • No strong radio absorption detected in the low-frequency spectra of radio-loud quasars at z > 5.6 

      Gloudemans, A. J.; Saxena, A.; Intema, H.; Callingham, J. R.; Duncan, K. J.; Rottgering, H. J. A.; Belladitta, S.; Hardcastle, M. J.; Harikane, Y.; Spingola, C. (2023-10-12)
      We present the low-frequency radio spectra of nine high-redshift quasars at 5:6 < z < 6:6 using the Giant Metre Radio Telescope band-3, -4, and -5 observations (∼300-1200 MHz), archival Low Frequency Array (LOFAR; 144 MHz), ...
    • A novel Bayesian approach for decomposing the radio emission of quasars: I. Modelling the radio excess in red quasars 

      Yue, B -H; Best, P N; Duncan, K J; Calistro-Rivera, G; Morabito, L K; Petley, J W; Prandoni, I; Rottgering, H. J. A.; Smith, D J B (2024-03-12)
      Studies show that both radio jets from the active galactic nuclei (AGNs) and the star formation (SF) activity in quasar host galaxies contribute to the quasar radio emission; yet their relative contributions across the ...