Browsing by Author "Tasse, C."

Now showing items 1-20 of 62

    • Alignment in the orientation of LOFAR radio sources 

      Osinga, E.; Miley, G. K.; Weeren, R. J. van; Shimwell, T. W.; Duncan, K. J.; Hardcastle, M. J.; Mechev, A. P.; Röttgering, H. J. A.; Tasse, C.; Williams, W. L. (2020-08-25)
      Various studies have laid claim to finding an alignment of the polarization vectors or radio jets of active galactic nuclei (AGN) over large distances, but these results have proven controversial and so far, there is no ...

    • Blazars in the LOFAR Two-Metre Sky Survey First Data Release 

      Mooney, S.; Quinn, J.; Callingham, J. R.; Morganti, R.; Duncan, K.; Morabito, Leah K.; Best, P. N.; Gürkan, G.; Hardcastle, M. J.; Prandoni, I.; Röttgering, H. J. A.; Sabater, J.; Shimwell, T. W.; Shulevski, A.; Tasse, C.; Williams, W. L. (2018-11-19)
      Historically, the blazar population has been poorly understood at low frequencies because survey sensitivity and angular resolution limitations have made it difficult to identify megahertz counterparts. We used the LOFAR ...

    • 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 ...

    • Coherent radio emission from a quiescent red dwarf indicative of star-planet interaction 

      Vedantham, H. K.; Callingham, J. R.; Shimwell, T. W.; Tasse, C.; Pope, B. J. S.; Bedell, M.; Snellen, I.; Best, P.; Hardcastle, M. J.; Haverkorn, M.; Mechev, A.; O'Sullivan, S. P.; Röttgering, H. J. A.; White, G. J. (2020-02-17)
      Low-frequency (ν ≲ 150 MHz) stellar radio emission is expected to originate in the outer corona at heights comparable to and larger than the stellar radius. Such emission from the Sun has been used to study coronal structure, ...

    • 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 ...

    • Exploring the radio-loudness of SDSS quasars with spectral stacking 

      Arnaudova, M. I.; Smith, D. J. B.; Hardcastle, M. J.; Das, Soumyadeep; Drake, A.; Duncan, Kenneth; Gürkan, G.; Magliocchetti, M.; Morabito, L. K.; Petley, J. W.; Shenoy, S.; Tasse, C. (2024-01-22)
      We use new 144 MHz observations over 5634 deg 2 from the LOFAR (Low Frequency Array) Two-metre Sky Survey (LoTSS) to compile the largest sample of uniformly selected, spectroscopically confirmed quasars from the 14th data ...

    • 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 ...

    • The Faraday Rotation Measure Grid of the LOFAR Two-metre Sky Survey: Data Release 2 

      O'Sullivan, S. P.; Shimwell, T. W.; Hardcastle, M. J.; Tasse, C.; Heald, G.; Carretti, E.; Brüggen, M.; Vacca, V.; Sobey, C.; Eck, C. L. Van; Horellou, C.; Beck, R.; Bilicki, M.; Bourke, S.; Botteon, A.; Croston, J. H.; Drabent, A.; Duncan, K.; Heesen, V.; Ideguchi, S.; Kirwan, M.; Lawlor, L.; Mingo, B.; Nikiel-Wroczyński, B.; Piotrowska, J.; Scaife, A. M. M.; Weeren, R. J. van (2023-01-02)
      A Faraday rotation measure (RM) catalogue, or RM Grid, is a valuable resource for the study of cosmic magnetism. Using the second data release (DR2) from the LOFAR Two-metre Sky Survey (LoTSS), we have produced a catalogue ...

    • 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). ...

    • 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. ...

    • The life cycle of radio galaxies in the LOFAR Lockman Hole field 

      Jurlin, N.; Morganti, R.; Brienza, M.; Mandal, S.; Maddox, N.; Duncan, K. J.; Shabala, S. S.; Hardcastle, M. J.; Prandoni, I.; Röttgering, H. J. A.; Mahatma, V.; Best, P. N.; Mingo, B.; Sabater, J.; Shimwell, T. W.; Tasse, C. (2020-06-08)
      Radio galaxies are known to go through cycles of activity, where phases of apparent quiescence can be followed by repeated activity of the central supermassive black hole. A better understanding of this cycle is crucial ...

    • The Lockman Hole project : LOFAR observations and spectral index properties of low-frequency radio sources 

      Mahony, E. K.; Morganti, R.; Prandoni, I.; Bemmel, I. M. van; Shimwell, T. W.; Brienza, M.; Best, P. N.; Brüggen, M.; Rivera, G. Calistro; Gasperin, F. de; Hardcastle, M. J.; Harwood, J. J.; Heald, G.; Jarvis, M. J.; Mandal, S.; Miley, G. K.; Retana-Montenegro, E.; Röttgering, H. J. A.; Sabater, J.; Tasse, C.; Velzen, S. van; Weeren, R. J. van; Williams, W. L.; White, G. J. (2016-12-11)
      The Lockman Hole is a well-studied extragalactic field with extensive multi-band ancillary data covering a wide range in frequency, essential for characterising the physical and evolutionary properties of the various source ...

    • LOFAR 144-MHz follow-up observations of GW170817 

      Broderick, J. W.; Shimwell, T. W.; Gourdji, K.; Rowlinson, A.; Nissanke, S.; Hotokezaka, K.; Jonker, P. G.; Tasse, C.; Hardcastle, M. J.; Oonk, J. B. R.; Fender, R. P.; Wijers, R. A. M. J.; Shulevski, A.; Stewart, A. J.; Veen, S. ter; Moss, V. A.; Wiel, M. H. D. van der; Nichols, D. A.; Piette, A.; Carbone, D.; Corbel, S.; Eislöffel, J.; Grießmeier, J. -M.; Keane, E. F.; Law, C. J.; Muñoz-Darias, T.; Pietka, M.; Serylak, M.; Horst, A. J. van der; Leeuwen, J. van; Wijnands, R.; Zarka, P.; Anderson, J. M.; Bentum, M. J.; Blaauw, R.; Brouw, W. N.; Brüggen, M.; Ciardi, B.; Vos, M. de; Duscha, S.; Fallows, R. A.; Franzen, T. M. O.; Garrett, M. A.; Gunst, A. W.; Hoeft, M.; Hörandel, J. R.; Iacobelli, M.; Jütte, E.; Koopmans, L. V. E.; Krankowski, A.; Maat, P.; Mann, G.; Mulder, H.; Nelles, A.; Paas, H.; Pandey-Pommier, M.; Pekal, R.; Reich, W.; Röttgering, H. J. A.; Schwarz, D. J.; Smirnov, O.; Soida, M.; Toribio, M. C.; Haarlem, M. P. van; Weeren, R. J. van; Vocks, C.; Wucknitz, O.; Zucca, P. (2020-06-01)
      We present low-radio-frequency follow-up observations of AT 2017gfo, the electromagnetic counterpart of GW170817, which was the first binary neutron star merger to be detected by Advanced LIGO-Virgo. These data, with a ...

    • LOFAR 150-MHz observations of the Boötes field: Catalogue and Source Counts 

      Williams, W. L.; Van Weeren, R. J.; Röttgering, H. J. A.; Best, P.; Dijkema, T. J.; Gasperin, F. de; Hardcastle, M. J.; Heald, G.; Prandoni, I.; Sabater, J.; Shimwell, T. W.; Tasse, C.; Bemmel, I. M. van; Brüggen, M.; Brunetti, G.; Conway, J. E.; Enßlin, T.; Engels, D.; Falcke, H.; Ferrari, C.; Haverkorn, M.; Jackson, N.; Jarvis, M. J.; Kapinska, A. D.; Mahony, E. K.; Miley, G. K.; Morabito, L. K.; Morganti, R.; Orrú, E.; Retana-Montenegro, E.; Sridhar, S. S.; Toribio, M. C.; White, G. J.; Wise, M. W.; Zwart, J. T. L. (2016-08-11)
      We present the first wide area (19 deg$^2$), deep ($\approx120-150$ {\mu}Jy beam$^{-1}$), high resolution ($5.6 \times 7.4$ arcsec) LOFAR High Band Antenna image of the Bo\"otes field made at 130-169 MHz. This image is at ...

    • LOFAR Deep Fields : Probing a broader population of polarized radio galaxies in ELAIS-N1 

      Ruiz, N. Herrera; O'Sullivan, S. P.; Vacca, V.; Jelić, V.; Nikiel-Wroczyński, B.; Bourke, S.; Sabater, J.; Dettmar, R. -J.; Heald, G.; Horellou, C.; Piras, S.; Sobey, C.; Shimwell, T. W.; Tasse, C.; Hardcastle, M. J.; Kondapally, R.; Chyży, K. T.; Iacobelli, M.; Best, P. N.; Brüggen, M.; Carretti, E.; Prandoni, I. (2021-04-07)
      We present deep polarimetric observations of the European Large Area ISO Survey-North 1 (ELAIS-N1) field using the Low Frequency Array (LOFAR) at 114.9-177.4 MHz. The ELAIS-N1 field is part of the LOFAR Two-metre Sky Survey ...

    • LOFAR discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45 

      Cassano, R.; Botteon, A.; Gennaro, G. Di; Brunetti, G.; Sereno, M.; Shimwell, T. W.; Weeren, R. J. van; Brüggen, M.; Gastaldello, F.; Izzo, L.; Bîrzan, L.; Bonafede, A.; Cuciti, V.; Gasperin, F. de; Rötttgering, H. J. A.; Hardcastle, M.; Mechev, A. P.; Tasse, C. (2019-08-19)
      In this Letter, we report the discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45 ($z=0.616$) with the LOw Frequency ARray (LOFAR) at 120-168 MHz. This is one of the most distant radio halos ...

    • LOFAR early-time search for coherent radio emission from GRB 180706A 

      Rowlinson, A.; Gourdji, K.; Meulen, K. van der; Meyers, Z. S.; Shimwell, T. W.; Veen, S. ter; Wijers, R. A. M. J.; Kuiack, M. J.; Shulevski, A.; Broderick, J. W.; Horst, A. J. van der; Tasse, C.; Hardcastle, M. J.; Mechev, A. P.; Williams, W. L. (2019-10-21)
      The nature of the central engines of gamma-ray bursts (GRBs) and the composition of their relativistic jets are still under debate. If the jets are Poynting flux dominated rather than baryon dominated, a coherent radio ...

    • LOFAR HBA observations of the Euclid Deep Field North (EDFN) 

      Bondi, M.; Scaramella, R.; Zamorani, G.; Ciliegi, P.; Vitello, F.; Arias, M.; Best, P.N.; Bonato, M.; Botteon, A.; Brienza, M.; Brunetti, G.; Hardcastle, M. J.; Magliocchetti, M.; Massaro, F.; Morabito, L. K; Pentericci, L.; Prandoni, I.; Röttgering, H. J. A.; Shimwell, T. W.; Tasse, C.; Weeren, R. J. van; White, G. J. (2024-03-18)
      We present the first deep (72 h of observations) radio image of the Euclid Deep Field North (EDFN) obtained with the LOw-Frequency ARray (LOFAR) High Band Antenna (HBA) at 144 MHz. The EDFN is the latest addition to the ...

    • 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 ...

    • 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 ...